attach and detach event handlers onappearing and ondisappearing to free up views for GC

src/App/Controls/DismissModalToolBarItem.cs

@@ -4,7 +4,7 @@ using Xamarin.Forms;
 
 namespace Bit.App.Controls
 {
-    public class DismissModalToolBarItem : ToolbarItem
+    public class DismissModalToolBarItem : ToolbarItem, IDisposable
     {
         private readonly ContentPage _page;
         private readonly Action _cancelClickedAction;
@@ -13,8 +13,9 @@ namespace Bit.App.Controls
         {
             _cancelClickedAction = cancelClickedAction;
             _page = page;
+            // TODO: init and dispose events from pages
+            InitEvents();
             Text = text ?? AppResources.Close;
-            Clicked += ClickedItem;
             Priority = -1;
         }
 
@@ -23,5 +24,15 @@ namespace Bit.App.Controls
             _cancelClickedAction?.Invoke();
             await _page.Navigation.PopModalAsync();
         }
+
+        public void InitEvents()
+        {
+            Clicked += ClickedItem;
+        }
+
+        public void Dispose()
+        {
+            Clicked -= ClickedItem;
+        }
     }
 }

src/App/Controls/FormEditorCell.cs

@@ -3,7 +3,7 @@ using Xamarin.Forms;
 
 namespace Bit.App.Controls
 {
-    public class FormEditorCell : ExtendedViewCell
+    public class FormEditorCell : ExtendedViewCell, IDisposable
     {
         public FormEditorCell(Keyboard entryKeyboard = null, double? height = null)
         {
@@ -26,7 +26,6 @@ namespace Bit.App.Controls
 
             stackLayout.Children.Add(Editor);
 
-            Tapped += FormEditorCell_Tapped;
             Editor.AdjustMarginsForDevice();
             stackLayout.AdjustPaddingForDevice();
 
@@ -39,5 +38,15 @@ namespace Bit.App.Controls
         {
             Editor.Focus();
         }
+
+        public void InitEvents()
+        {
+            Tapped += FormEditorCell_Tapped;
+        }
+
+        public void Dispose()
+        {
+            Tapped -= FormEditorCell_Tapped;
+        }
     }
 }

src/App/Controls/FormEntryCell.cs

@@ -5,8 +5,11 @@ using XLabs.Ioc;
 
 namespace Bit.App.Controls
 {
-    public class FormEntryCell : ExtendedViewCell
+    public class FormEntryCell : ExtendedViewCell, IDisposable
     {
+        private VisualElement _nextElement;
+        private TapGestureRecognizer _tgr;
+
         public FormEntryCell(
             string labelText,
             Keyboard entryKeyboard = null,
@@ -17,6 +20,8 @@ namespace Bit.App.Controls
             Thickness? containerPadding = null,
             bool useButton = false)
         {
+            _nextElement = nextElement;
+
             if(!useLabelAsPlaceholder)
             {
                 Label = new Label
@@ -47,7 +52,6 @@ namespace Bit.App.Controls
             if(nextElement != null)
             {
                 Entry.ReturnType = Enums.ReturnType.Next;
-                Entry.Completed += (object sender, EventArgs e) => { nextElement.Focus(); };
             }
 
             var imageStackLayout = new StackLayout
@@ -61,8 +65,7 @@ namespace Bit.App.Controls
 
             if(imageSource != null)
             {
-                var tgr = new TapGestureRecognizer();
+                _tgr = new TapGestureRecognizer();
-                tgr.Tapped += Tgr_Tapped;
 
                 var theImage = new Image
                 {
@@ -70,7 +73,7 @@ namespace Bit.App.Controls
                     HorizontalOptions = LayoutOptions.Start,
                     VerticalOptions = LayoutOptions.Center
                 };
-                theImage.GestureRecognizers.Add(tgr);
+                theImage.GestureRecognizers.Add(_tgr);
 
                 imageStackLayout.Children.Add(theImage);
             }
@@ -126,8 +129,6 @@ namespace Bit.App.Controls
                 }
             }
 
-            Tapped += FormEntryCell_Tapped;
-
             View = imageStackLayout;
         }
 
@@ -135,6 +136,21 @@ namespace Bit.App.Controls
         public ExtendedEntry Entry { get; private set; }
         public ExtendedButton Button { get; private set; }
 
+        public void InitEvents()
+        {
+            if(_nextElement != null)
+            {
+                Entry.Completed += Entry_Completed;
+            }
+
+            if(_tgr != null)
+            {
+                _tgr.Tapped += Tgr_Tapped;
+            }
+            
+            Tapped += FormEntryCell_Tapped;
+        }
+
         private void Tgr_Tapped(object sender, EventArgs e)
         {
             Entry.Focus();
@@ -144,5 +160,21 @@ namespace Bit.App.Controls
         {
             Entry.Focus();
         }
+
+        private void Entry_Completed(object sender, EventArgs e)
+        {
+            _nextElement?.Focus();
+        }
+
+        public void Dispose()
+        {
+            if(_tgr != null)
+            {
+                _tgr.Tapped -= Tgr_Tapped;
+            }
+
+            Tapped -= FormEntryCell_Tapped;
+            Entry.Completed -= Entry_Completed;
+        }
     }
 }

src/App/Controls/FormPickerCell.cs

@@ -1,5 +1,4 @@
 using System;
-using Bit.App.Resources;
 using Xamarin.Forms;
 
 namespace Bit.App.Controls
@@ -42,8 +41,6 @@ namespace Bit.App.Controls
             Picker.AdjustMarginsForDevice();
             stackLayout.AdjustPaddingForDevice();
 
-            Tapped += FormPickerCell_Tapped;
-
             View = stackLayout;
         }
 
@@ -54,5 +51,15 @@ namespace Bit.App.Controls
         {
             Picker.Focus();
         }
+
+        public void InitEvents()
+        {
+            Tapped += FormPickerCell_Tapped;
+        }
+
+        public void Dispose()
+        {
+            Tapped -= FormPickerCell_Tapped;
+        }
     }
 }

src/App/Controls/PinControl.cs

@@ -22,7 +22,6 @@ namespace Bit.App.Controls
                 MaxLength = 4,
                 Margin = new Thickness(0, int.MaxValue, 0, 0)
             };
-            Entry.TextChanged += Entry_TextChanged;
 
             if(Device.OS == TargetPlatform.Android)
             {
@@ -30,6 +29,9 @@ namespace Bit.App.Controls
             }
         }
 
+        public Label Label { get; set; }
+        public ExtendedEntry Entry { get; set; }
+
         private void Entry_TextChanged(object sender, TextChangedEventArgs e)
         {
             if(e.NewTextValue.Length >= 4)
@@ -38,7 +40,14 @@ namespace Bit.App.Controls
             }
         }
 
-        public Label Label { get; set; }
+        public void InitEvents()
-        public ExtendedEntry Entry { get; set; }
+        {
+            Entry.TextChanged += Entry_TextChanged;
+        }
+
+        public void Dispose()
+        {
+            Entry.TextChanged -= Entry_TextChanged;
+        }
     }
 }

src/App/Controls/StepperCell.cs

@@ -34,8 +34,6 @@ namespace Bit.App.Controls
                 Value = value
             };
 
-            Stepper.ValueChanged += Stepper_ValueChanged;
-
             var stackLayout = new StackLayout
             {
                 Orientation = StackOrientation.Horizontal,
@@ -56,13 +54,23 @@ namespace Bit.App.Controls
             View = stackLayout;
         }
 
+        public Label Label { get; private set; }
+        public Label StepperValueLabel { get; private set; }
+        public Stepper Stepper { get; private set; }
+
         private void Stepper_ValueChanged(object sender, ValueChangedEventArgs e)
         {
             StepperValueLabel.Text = e.NewValue.ToString();
         }
 
-        public Label Label { get; private set; }
+        public void InitEvents()
-        public Label StepperValueLabel { get; private set; }
+        {
-        public Stepper Stepper { get; private set; }
+            Stepper.ValueChanged += Stepper_ValueChanged;
+        }
+
+        public void Dispose()
+        {
+            Stepper.ValueChanged -= Stepper_ValueChanged;
+        }
     }
 }

src/App/Pages/Lock/LockPasswordPage.cs

@@ -38,7 +38,6 @@ namespace Bit.App.Pages
                 useLabelAsPlaceholder: true, imageSource: "lock", containerPadding: padding);
 
             PasswordCell.Entry.ReturnType = Enums.ReturnType.Go;
-            PasswordCell.Entry.Completed += Entry_Completed;
 
             var table = new ExtendedTableView
             {
@@ -99,7 +98,16 @@ namespace Bit.App.Pages
         protected override void OnAppearing()
         {
             base.OnAppearing();
+            PasswordCell.InitEvents();
             PasswordCell.Entry.FocusWithDelay();
+            PasswordCell.Entry.Completed += Entry_Completed;
+        }
+
+        protected override void OnDisappearing()
+        {
+            base.OnDisappearing();
+            PasswordCell.Dispose();
+            PasswordCell.Entry.Completed -= Entry_Completed;
         }
 
         protected async Task CheckPasswordAsync()

src/App/Pages/Lock/LockPinPage.cs

@@ -15,6 +15,7 @@ namespace Bit.App.Pages
     {
         private readonly IAuthService _authService;
         private readonly ISettings _settings;
+        private TapGestureRecognizer _tgr;
 
         public LockPinPage()
         {
@@ -39,7 +40,6 @@ namespace Bit.App.Pages
             };
 
             PinControl = new PinControl();
-            PinControl.OnPinEntered += PinEntered;
             PinControl.Label.SetBinding<PinPageModel>(Label.TextProperty, s => s.LabelText);
             PinControl.Entry.SetBinding<PinPageModel>(Entry.TextProperty, s => s.PIN);
 
@@ -60,14 +60,13 @@ namespace Bit.App.Pages
                 Children = { PinControl.Label, instructionLabel, logoutButton, PinControl.Entry }
             };
 
-            var tgr = new TapGestureRecognizer();
+            _tgr = new TapGestureRecognizer();
-            tgr.Tapped += Tgr_Tapped;
+            PinControl.Label.GestureRecognizers.Add(_tgr);
-            PinControl.Label.GestureRecognizers.Add(tgr);
+            instructionLabel.GestureRecognizers.Add(_tgr);
-            instructionLabel.GestureRecognizers.Add(tgr);
 
             Title = AppResources.VerifyPIN;
             Content = stackLayout;
-            Content.GestureRecognizers.Add(tgr);
+            Content.GestureRecognizers.Add(_tgr);
             BindingContext = Model;
         }
 
@@ -79,9 +78,20 @@ namespace Bit.App.Pages
         protected override void OnAppearing()
         {
             base.OnAppearing();
+            _tgr.Tapped += Tgr_Tapped;
+            PinControl.OnPinEntered += PinEntered;
+            PinControl.InitEvents();
             PinControl.Entry.FocusWithDelay();
         }
 
+        protected override void OnDisappearing()
+        {
+            base.OnDisappearing();
+            _tgr.Tapped -= Tgr_Tapped;
+            PinControl.OnPinEntered -= PinEntered;
+            PinControl.Dispose();
+        }
+
         protected void PinEntered(object sender, EventArgs args)
         {
             if(Model.PIN == _authService.PIN)

src/App/Pages/LoginPage.cs

@@ -74,7 +74,6 @@ namespace Bit.App.Pages
             }
 
             PasswordCell.Entry.ReturnType = Enums.ReturnType.Go;
-            PasswordCell.Entry.Completed += Entry_Completed;
 
             var table = new ExtendedTableView
             {
@@ -136,6 +135,10 @@ namespace Bit.App.Pages
         protected override void OnAppearing()
         {
             base.OnAppearing();
+            PasswordCell.InitEvents();
+            EmailCell.InitEvents();
+
+            PasswordCell.Entry.Completed += Entry_Completed;
             MessagingCenter.Send(Application.Current, "ShowStatusBar", true);
 
             if(string.IsNullOrWhiteSpace(_email))
@@ -151,6 +154,14 @@ namespace Bit.App.Pages
             }
         }
 
+        protected override void OnDisappearing()
+        {
+            base.OnDisappearing();
+            PasswordCell.Dispose();
+            EmailCell.Dispose();
+            PasswordCell.Entry.Completed -= Entry_Completed;
+        }
+
         private async void Entry_Completed(object sender, EventArgs e)
         {
             await LogIn();

src/App/Pages/LoginTwoFactorPage.cs

@@ -64,7 +64,6 @@ namespace Bit.App.Pages
 
             CodeCell.Entry.Keyboard = Keyboard.Numeric;
             CodeCell.Entry.ReturnType = Enums.ReturnType.Go;
-            CodeCell.Entry.Completed += Entry_Completed;
 
             var table = new ExtendedTableView
             {
@@ -129,7 +128,16 @@ namespace Bit.App.Pages
         protected override void OnAppearing()
         {
             base.OnAppearing();
+            CodeCell.InitEvents();
             CodeCell.Entry.FocusWithDelay();
+            CodeCell.Entry.Completed += Entry_Completed;
+        }
+
+        protected override void OnDisappearing()
+        {
+            base.OnDisappearing();
+            CodeCell.Dispose();
+            CodeCell.Entry.Completed -= Entry_Completed;
         }
 
         private void Lost2FAApp()

src/App/Pages/PasswordHintPage.cs

@@ -38,7 +38,6 @@ namespace Bit.App.Pages
                 useLabelAsPlaceholder: true, imageSource: "envelope", containerPadding: padding);
 
             EmailCell.Entry.ReturnType = Enums.ReturnType.Go;
-            EmailCell.Entry.Completed += Entry_Completed;
 
             var table = new ExtendedTableView
             {
@@ -93,9 +92,18 @@ namespace Bit.App.Pages
         protected override void OnAppearing()
         {
             base.OnAppearing();
+            EmailCell.InitEvents();
+            EmailCell.Entry.Completed += Entry_Completed;
             EmailCell.Entry.FocusWithDelay();
         }
 
+        protected override void OnDisappearing()
+        {
+            base.OnDisappearing();
+            EmailCell.Dispose();
+            EmailCell.Entry.Completed -= Entry_Completed;
+        }
+
         private async void Entry_Completed(object sender, EventArgs e)
         {
             await SubmitAsync();

src/App/Pages/RegisterPage.cs

@@ -58,7 +58,6 @@ namespace Bit.App.Pages
                 containerPadding: padding);
 
             PasswordHintCell.Entry.ReturnType = Enums.ReturnType.Done;
-            PasswordHintCell.Entry.Completed += Entry_Completed;
 
             var table = new FormTableView
             {
@@ -144,8 +143,22 @@ namespace Bit.App.Pages
         {
             base.OnAppearing();
             MessagingCenter.Send(Application.Current, "ShowStatusBar", true);
+            EmailCell.InitEvents();
+            PasswordCell.InitEvents();
+            PasswordHintCell.InitEvents();
+            ConfirmPasswordCell.InitEvents();
+            PasswordHintCell.Entry.Completed += Entry_Completed;
             EmailCell.Entry.FocusWithDelay();
         }
+        protected override void OnDisappearing()
+        {
+            base.OnDisappearing();
+            EmailCell.Dispose();
+            PasswordCell.Dispose();
+            PasswordHintCell.Dispose();
+            ConfirmPasswordCell.Dispose();
+            PasswordHintCell.Entry.Completed -= Entry_Completed;
+        }
 
         private async void Entry_Completed(object sender, EventArgs e)
         {

src/App/Pages/Settings/SettingsAddFolderPage.cs

@@ -28,9 +28,11 @@ namespace Bit.App.Pages
             Init();
         }
 
+        public FormEntryCell NameCell { get; set; }
+
         private void Init()
         {
-            var nameCell = new FormEntryCell(AppResources.Name);
+            NameCell = new FormEntryCell(AppResources.Name);
 
             var table = new ExtendedTableView
             {
@@ -41,7 +43,7 @@ namespace Bit.App.Pages
                 {
                     new TableSection()
                     {
-                        nameCell
+                        NameCell
                     }
                 }
             };
@@ -60,7 +62,7 @@ namespace Bit.App.Pages
                     return;
                 }
 
-                if(string.IsNullOrWhiteSpace(nameCell.Entry.Text))
+                if(string.IsNullOrWhiteSpace(NameCell.Entry.Text))
                 {
                     await DisplayAlert(AppResources.AnErrorHasOccurred, string.Format(AppResources.ValidationFieldRequired,
                         AppResources.Name), AppResources.Ok);
@@ -69,7 +71,7 @@ namespace Bit.App.Pages
 
                 var folder = new Folder
                 {
-                    Name = nameCell.Entry.Text.Encrypt()
+                    Name = NameCell.Entry.Text.Encrypt()
                 };
 
                 _userDialogs.ShowLoading(AppResources.Saving, MaskType.Black);
@@ -105,12 +107,19 @@ namespace Bit.App.Pages
         protected override void OnAppearing()
         {
             base.OnAppearing();
+            NameCell.InitEvents();
             if(!_connectivity.IsConnected)
             {
                 AlertNoConnection();
             }
         }
 
+        protected override void OnDisappearing()
+        {
+            base.OnDisappearing();
+            NameCell.Dispose();
+        }
+
         private void AlertNoConnection()
         {
             DisplayAlert(AppResources.InternetConnectionRequiredTitle, AppResources.InternetConnectionRequiredMessage, AppResources.Ok);

src/App/Pages/Settings/SettingsEditFolderPage.cs

@@ -29,6 +29,9 @@ namespace Bit.App.Pages
             Init();
         }
 
+        public FormEntryCell NameCell { get; set; }
+        public ExtendedTextCell DeleteCell { get; set; }
+
         private void Init()
         {
             var folder = _folderService.GetByIdAsync(_folderId).GetAwaiter().GetResult();
@@ -38,11 +41,10 @@ namespace Bit.App.Pages
                 return;
             }
 
-            var nameCell = new FormEntryCell(AppResources.Name);
+            NameCell = new FormEntryCell(AppResources.Name);
-            nameCell.Entry.Text = folder.Name.Decrypt();
+            NameCell.Entry.Text = folder.Name.Decrypt();
 
-            var deleteCell = new ExtendedTextCell { Text = AppResources.Delete, TextColor = Color.Red };
+            DeleteCell = new ExtendedTextCell { Text = AppResources.Delete, TextColor = Color.Red };
-            deleteCell.Tapped += DeleteCell_Tapped;
 
             var mainTable = new ExtendedTableView
             {
@@ -54,11 +56,11 @@ namespace Bit.App.Pages
                 {
                     new TableSection
                     {
-                        nameCell
+                        NameCell
                     },
                     new TableSection
                     {
-                        deleteCell
+                        DeleteCell
                     }
                 }
             };
@@ -77,14 +79,14 @@ namespace Bit.App.Pages
                     return;
                 }
 
-                if(string.IsNullOrWhiteSpace(nameCell.Entry.Text))
+                if(string.IsNullOrWhiteSpace(NameCell.Entry.Text))
                 {
                     await DisplayAlert(AppResources.AnErrorHasOccurred, string.Format(AppResources.ValidationFieldRequired,
                         AppResources.Name), AppResources.Ok);
                     return;
                 }
 
-                folder.Name = nameCell.Entry.Text.Encrypt();
+                folder.Name = NameCell.Entry.Text.Encrypt();
 
                 _userDialogs.ShowLoading(AppResources.Saving, MaskType.Black);
                 var saveResult = await _folderService.SaveAsync(folder);
@@ -119,12 +121,22 @@ namespace Bit.App.Pages
         protected override void OnAppearing()
         {
             base.OnAppearing();
+            NameCell.InitEvents();
+            DeleteCell.Tapped += DeleteCell_Tapped;
+
             if(!_connectivity.IsConnected)
             {
                 AlertNoConnection();
             }
         }
 
+        protected override void OnDisappearing()
+        {
+            base.OnDisappearing();
+            NameCell.Dispose();
+            DeleteCell.Tapped -= DeleteCell_Tapped;
+        }
+
         private async void DeleteCell_Tapped(object sender, EventArgs e)
         {
             if(!_connectivity.IsConnected)

src/App/Pages/Settings/SettingsPinPage.cs

@@ -40,7 +40,6 @@ namespace Bit.App.Pages
             };
 
             PinControl = new PinControl();
-            PinControl.OnPinEntered += PinEntered;
             PinControl.Label.SetBinding<PinPageModel>(Label.TextProperty, s => s.LabelText);
             PinControl.Entry.SetBinding<PinPageModel>(Entry.TextProperty, s => s.PIN);
 
@@ -75,9 +74,18 @@ namespace Bit.App.Pages
         protected override void OnAppearing()
         {
             base.OnAppearing();
+            PinControl.OnPinEntered += PinEntered;
+            PinControl.InitEvents();
             PinControl.Entry.FocusWithDelay();
         }
 
+        protected override void OnDisappearing()
+        {
+            base.OnDisappearing();
+            PinControl.Dispose();
+            PinControl.OnPinEntered -= PinEntered;
+        }
+
         protected void PinEntered(object sender, EventArgs args)
         {
             OnPinEntered.Invoke(this, null);

src/App/Pages/Tools/ToolsPasswordGeneratorSettingsPage.cs

@@ -53,7 +53,6 @@ namespace Bit.App.Pages
                 Text = "!@#$%^&*",
                 On = _settings.GetValueOrDefault(Constants.PasswordGeneratorSpecial, true)
             };
-            SpecialCell.OnChanged += SpecialCell_OnChanged;
 
             NumbersCell = new ExtendedSwitchCell
             {
@@ -67,7 +66,6 @@ namespace Bit.App.Pages
                 Text = AppResources.AvoidAmbiguousCharacters,
                 On = !_settings.GetValueOrDefault(Constants.PasswordGeneratorAmbiguous, false)
             };
-            AvoidAmbiguousCell.OnChanged += AvoidAmbiguousCell_OnChanged; ;
 
             NumbersMinCell = new StepperCell(AppResources.MinNumbers, 
                 _settings.GetValueOrDefault(Constants.PasswordGeneratorMinNumbers, 1), 0, 5, 1);
@@ -111,8 +109,19 @@ namespace Bit.App.Pages
             Content = table;
         }
 
+        protected override void OnAppearing()
+        {
+            base.OnAppearing();
+            SpecialCell.OnChanged += SpecialCell_OnChanged;
+            AvoidAmbiguousCell.OnChanged += AvoidAmbiguousCell_OnChanged;
+        }
+
         protected override void OnDisappearing()
         {
+            base.OnDisappearing();
+            SpecialCell.OnChanged -= SpecialCell_OnChanged;
+            AvoidAmbiguousCell.OnChanged -= AvoidAmbiguousCell_OnChanged;
+
             _settings.AddOrUpdateValue(Constants.PasswordGeneratorMinNumbers, 
                 Convert.ToInt32(NumbersMinCell.Stepper.Value));
 

src/App/Pages/Vault/VaultAddLoginPage.cs

@@ -46,32 +46,37 @@ namespace Bit.App.Pages
         }
 
         public FormEntryCell PasswordCell { get; private set; }
+        public FormEntryCell UsernameCell { get; private set; }
+        public FormEntryCell UriCell { get; private set; }
+        public FormEntryCell NameCell { get; private set; }
+        public FormEditorCell NotesCell { get; private set; }
+        public FormPickerCell FolderCell { get; private set; }
+        public ExtendedTextCell GenerateCell { get; private set; }
 
         private void Init()
         {
-            var notesCell = new FormEditorCell(height: 90);
+            NotesCell = new FormEditorCell(height: 90);
-            PasswordCell = new FormEntryCell(AppResources.Password, isPassword: true, nextElement: notesCell.Editor,
+            PasswordCell = new FormEntryCell(AppResources.Password, isPassword: true, nextElement: NotesCell.Editor,
                 useButton: true);
             PasswordCell.Button.Image = "eye";
-            PasswordCell.Button.Clicked += PasswordButton_Clicked;
             PasswordCell.Entry.DisableAutocapitalize = true;
             PasswordCell.Entry.Autocorrect = false;
             PasswordCell.Entry.FontFamily = Device.OnPlatform(iOS: "Courier", Android: "monospace", WinPhone: "Courier");
 
-            var usernameCell = new FormEntryCell(AppResources.Username, nextElement: PasswordCell.Entry);
+            UsernameCell = new FormEntryCell(AppResources.Username, nextElement: PasswordCell.Entry);
-            usernameCell.Entry.DisableAutocapitalize = true;
+            UsernameCell.Entry.DisableAutocapitalize = true;
-            usernameCell.Entry.Autocorrect = false;
+            UsernameCell.Entry.Autocorrect = false;
 
-            var uriCell = new FormEntryCell(AppResources.URI, Keyboard.Url, nextElement: usernameCell.Entry);
+            UriCell = new FormEntryCell(AppResources.URI, Keyboard.Url, nextElement: UsernameCell.Entry);
             if(!string.IsNullOrWhiteSpace(_defaultUri))
             {
-                uriCell.Entry.Text = _defaultUri;
+                UriCell.Entry.Text = _defaultUri;
             }
 
-            var nameCell = new FormEntryCell(AppResources.Name, nextElement: uriCell.Entry);
+            NameCell = new FormEntryCell(AppResources.Name, nextElement: UriCell.Entry);
             if(!string.IsNullOrWhiteSpace(_defaultName))
             {
-                nameCell.Entry.Text = _defaultName;
+                NameCell.Entry.Text = _defaultName;
             }
 
             var folderOptions = new List<string> { AppResources.FolderNone };
@@ -81,14 +86,13 @@ namespace Bit.App.Pages
             {
                 folderOptions.Add(folder.Name.Decrypt());
             }
-            var folderCell = new FormPickerCell(AppResources.Folder, folderOptions.ToArray());
+            FolderCell = new FormPickerCell(AppResources.Folder, folderOptions.ToArray());
 
-            var generateCell = new ExtendedTextCell
+            GenerateCell = new ExtendedTextCell
             {
                 Text = AppResources.GeneratePassword,
                 ShowDisclousure = true
             };
-            generateCell.Tapped += GenerateCell_Tapped; ;
 
             var favoriteCell = new ExtendedSwitchCell { Text = AppResources.Favorite };
 
@@ -101,20 +105,20 @@ namespace Bit.App.Pages
                 {
                     new TableSection(AppResources.LoginInformation)
                     {
-                        nameCell,
+                        NameCell,
-                        uriCell,
+                        UriCell,
-                        usernameCell,
+                        UsernameCell,
                         PasswordCell,
-                        generateCell
+                        GenerateCell
                     },
                     new TableSection
                     {
-                        folderCell,
+                        FolderCell,
                         favoriteCell
                     },
                     new TableSection(AppResources.Notes)
                     {
-                        notesCell
+                        NotesCell
                     }
                 }
             };
@@ -137,7 +141,7 @@ namespace Bit.App.Pages
                     return;
                 }
 
-                if(string.IsNullOrWhiteSpace(nameCell.Entry.Text))
+                if(string.IsNullOrWhiteSpace(NameCell.Entry.Text))
                 {
                     await DisplayAlert(AppResources.AnErrorHasOccurred, string.Format(AppResources.ValidationFieldRequired,
                         AppResources.Name), AppResources.Ok);
@@ -146,17 +150,17 @@ namespace Bit.App.Pages
 
                 var login = new Login
                 {
-                    Uri = uriCell.Entry.Text?.Encrypt(),
+                    Uri = UriCell.Entry.Text?.Encrypt(),
-                    Name = nameCell.Entry.Text?.Encrypt(),
+                    Name = NameCell.Entry.Text?.Encrypt(),
-                    Username = usernameCell.Entry.Text?.Encrypt(),
+                    Username = UsernameCell.Entry.Text?.Encrypt(),
                     Password = PasswordCell.Entry.Text?.Encrypt(),
-                    Notes = notesCell.Editor.Text?.Encrypt(),
+                    Notes = NotesCell.Editor.Text?.Encrypt(),
                     Favorite = favoriteCell.On
                 };
 
-                if(folderCell.Picker.SelectedIndex > 0)
+                if(FolderCell.Picker.SelectedIndex > 0)
                 {
-                    login.FolderId = folders.ElementAt(folderCell.Picker.SelectedIndex - 1).Id;
+                    login.FolderId = folders.ElementAt(FolderCell.Picker.SelectedIndex - 1).Id;
                 }
 
                 _userDialogs.ShowLoading(AppResources.Saving, MaskType.Black);
@@ -203,6 +207,15 @@ namespace Bit.App.Pages
                 AlertNoConnection();
             }
 
+            PasswordCell.InitEvents();
+            UsernameCell.InitEvents();
+            UriCell.InitEvents();
+            NameCell.InitEvents();
+            NotesCell.InitEvents();
+            FolderCell.InitEvents();
+            PasswordCell.Button.Clicked += PasswordButton_Clicked;
+            GenerateCell.Tapped += GenerateCell_Tapped;
+
             if(!_fromAutofill && !_settings.GetValueOrDefault(AddedLoginAlertKey, false))
             {
                 _settings.AddOrUpdateValue(AddedLoginAlertKey, true);
@@ -219,6 +232,19 @@ namespace Bit.App.Pages
             }
         }
 
+        protected override void OnDisappearing()
+        {
+            base.OnDisappearing();
+            PasswordCell.Dispose();
+            UsernameCell.Dispose();
+            UriCell.Dispose();
+            NameCell.Dispose();
+            NotesCell.Dispose();
+            FolderCell.Dispose();
+            PasswordCell.Button.Clicked -= PasswordButton_Clicked;
+            GenerateCell.Tapped -= GenerateCell_Tapped;
+        }
+
         private void PasswordButton_Clicked(object sender, EventArgs e)
         {
             PasswordCell.Entry.InvokeToggleIsPassword();

src/App/Pages/Vault/VaultEditLoginPage.cs

@@ -33,6 +33,13 @@ namespace Bit.App.Pages
         }
 
         public FormEntryCell PasswordCell { get; private set; }
+        public FormEntryCell UsernameCell { get; private set; }
+        public FormEntryCell UriCell { get; private set; }
+        public FormEntryCell NameCell { get; private set; }
+        public FormEditorCell NotesCell { get; private set; }
+        public FormPickerCell FolderCell { get; private set; }
+        public ExtendedTextCell GenerateCell { get; private set; }
+        public ExtendedTextCell DeleteCell { get; private set; }
 
         private void Init()
         {
@@ -43,34 +50,32 @@ namespace Bit.App.Pages
                 return;
             }
 
-            var notesCell = new FormEditorCell(height: 90);
+            NotesCell = new FormEditorCell(height: 90);
-            notesCell.Editor.Text = login.Notes?.Decrypt();
+            NotesCell.Editor.Text = login.Notes?.Decrypt();
 
-            PasswordCell = new FormEntryCell(AppResources.Password, isPassword: true, nextElement: notesCell.Editor,
+            PasswordCell = new FormEntryCell(AppResources.Password, isPassword: true, nextElement: NotesCell.Editor,
                 useButton: true);
             PasswordCell.Entry.Text = login.Password?.Decrypt();
             PasswordCell.Button.Image = "eye";
-            PasswordCell.Button.Clicked += PasswordButton_Clicked;
             PasswordCell.Entry.DisableAutocapitalize = true;
             PasswordCell.Entry.Autocorrect = false;
             PasswordCell.Entry.FontFamily = Device.OnPlatform(iOS: "Courier", Android: "monospace", WinPhone: "Courier");
 
-            var usernameCell = new FormEntryCell(AppResources.Username, nextElement: PasswordCell.Entry);
+            UsernameCell = new FormEntryCell(AppResources.Username, nextElement: PasswordCell.Entry);
-            usernameCell.Entry.Text = login.Username?.Decrypt();
+            UsernameCell.Entry.Text = login.Username?.Decrypt();
-            usernameCell.Entry.DisableAutocapitalize = true;
+            UsernameCell.Entry.DisableAutocapitalize = true;
-            usernameCell.Entry.Autocorrect = false;
+            UsernameCell.Entry.Autocorrect = false;
 
-            var uriCell = new FormEntryCell(AppResources.URI, Keyboard.Url, nextElement: usernameCell.Entry);
+            UriCell = new FormEntryCell(AppResources.URI, Keyboard.Url, nextElement: UsernameCell.Entry);
-            uriCell.Entry.Text = login.Uri?.Decrypt();
+            UriCell.Entry.Text = login.Uri?.Decrypt();
-            var nameCell = new FormEntryCell(AppResources.Name, nextElement: uriCell.Entry);
+            NameCell = new FormEntryCell(AppResources.Name, nextElement: UriCell.Entry);
-            nameCell.Entry.Text = login.Name?.Decrypt();
+            NameCell.Entry.Text = login.Name?.Decrypt();
 
-            var generateCell = new ExtendedTextCell
+            GenerateCell = new ExtendedTextCell
             {
                 Text = AppResources.GeneratePassword,
                 ShowDisclousure = true
             };
-            generateCell.Tapped += GenerateCell_Tapped; ;
 
             var folderOptions = new List<string> { AppResources.FolderNone };
             var folders = _folderService.GetAllAsync().GetAwaiter().GetResult()
@@ -87,8 +92,8 @@ namespace Bit.App.Pages
 
                 folderOptions.Add(folder.Name.Decrypt());
             }
-            var folderCell = new FormPickerCell(AppResources.Folder, folderOptions.ToArray());
+            FolderCell = new FormPickerCell(AppResources.Folder, folderOptions.ToArray());
-            folderCell.Picker.SelectedIndex = selectedIndex;
+            FolderCell.Picker.SelectedIndex = selectedIndex;
 
             var favoriteCell = new ExtendedSwitchCell
             {
@@ -96,8 +101,7 @@ namespace Bit.App.Pages
                 On = login.Favorite
             };
 
-            var deleteCell = new ExtendedTextCell { Text = AppResources.Delete, TextColor = Color.Red };
+            DeleteCell = new ExtendedTextCell { Text = AppResources.Delete, TextColor = Color.Red };
-            deleteCell.Tapped += DeleteCell_Tapped;
 
             var table = new ExtendedTableView
             {
@@ -108,24 +112,24 @@ namespace Bit.App.Pages
                 {
                     new TableSection(AppResources.LoginInformation)
                     {
-                        nameCell,
+                        NameCell,
-                        uriCell,
+                        UriCell,
-                        usernameCell,
+                        UsernameCell,
                         PasswordCell,
-                        generateCell
+                        GenerateCell
                     },
                     new TableSection
                     {
-                        folderCell,
+                        FolderCell,
                         favoriteCell
                     },
                     new TableSection(AppResources.Notes)
                     {
-                        notesCell
+                        NotesCell
                     },
                     new TableSection
                     {
-                        deleteCell
+                        DeleteCell
                     }
                 }
             };
@@ -148,23 +152,23 @@ namespace Bit.App.Pages
                     return;
                 }
 
-                if(string.IsNullOrWhiteSpace(nameCell.Entry.Text))
+                if(string.IsNullOrWhiteSpace(NameCell.Entry.Text))
                 {
                     await DisplayAlert(AppResources.AnErrorHasOccurred, string.Format(AppResources.ValidationFieldRequired,
                         AppResources.Name), AppResources.Ok);
                     return;
                 }
 
-                login.Uri = uriCell.Entry.Text?.Encrypt();
+                login.Uri = UriCell.Entry.Text?.Encrypt();
-                login.Name = nameCell.Entry.Text?.Encrypt();
+                login.Name = NameCell.Entry.Text?.Encrypt();
-                login.Username = usernameCell.Entry.Text?.Encrypt();
+                login.Username = UsernameCell.Entry.Text?.Encrypt();
                 login.Password = PasswordCell.Entry.Text?.Encrypt();
-                login.Notes = notesCell.Editor.Text?.Encrypt();
+                login.Notes = NotesCell.Editor.Text?.Encrypt();
                 login.Favorite = favoriteCell.On;
 
-                if(folderCell.Picker.SelectedIndex > 0)
+                if(FolderCell.Picker.SelectedIndex > 0)
                 {
-                    login.FolderId = folders.ElementAt(folderCell.Picker.SelectedIndex - 1).Id;
+                    login.FolderId = folders.ElementAt(FolderCell.Picker.SelectedIndex - 1).Id;
                 }
                 else
                 {
@@ -208,6 +212,30 @@ namespace Bit.App.Pages
             {
                 AlertNoConnection();
             }
+
+            PasswordCell.InitEvents();
+            UsernameCell.InitEvents();
+            UriCell.InitEvents();
+            NameCell.InitEvents();
+            NotesCell.InitEvents();
+            FolderCell.InitEvents();
+            PasswordCell.Button.Clicked += PasswordButton_Clicked;
+            GenerateCell.Tapped += GenerateCell_Tapped;
+            DeleteCell.Tapped += DeleteCell_Tapped;
+        }
+
+        protected override void OnDisappearing()
+        {
+            base.OnDisappearing();
+            PasswordCell.Dispose();
+            UsernameCell.Dispose();
+            UriCell.Dispose();
+            NameCell.Dispose();
+            NotesCell.Dispose();
+            FolderCell.Dispose();
+            PasswordCell.Button.Clicked -= PasswordButton_Clicked;
+            GenerateCell.Tapped -= GenerateCell_Tapped;
+            DeleteCell.Tapped -= DeleteCell_Tapped;
         }
 
         private void PasswordButton_Clicked(object sender, EventArgs e)