Develop Reference

Isolated storage in In a multi-page c#

I have created two pages in the application ...
There on the front page Tkstpeix write your name when entering the storage and set up the application on this page,
And when you enter the second page in the application name does not come out!
Example:
When I open the app and type in my name "Ibra" the text box on the second page my name does not appear!
->Page1:
using myProject.Model;
public partial class Test1 : PhoneApplicationPage
{
IsolatedStorageSettings Data = IsolatedStorageSettings.ApplicationSettings;
List<UserData> ObjUserDataList = new List<UserData>();
public Test1()
{
InitializeComponent();
this.Loaded += Test1_Loaded;
}
private void Test1_Loaded(object sender, RoutedEventArgs e)
{
if (Data.Contains("UserNameData"))
{
NavigationService.Navigate(new Uri("/Test2.xaml", UriKind.Relative));
}
}
private void NameBox_GotFocus(object sender, RoutedEventArgs e)
{
TextBox tb = (TextBox)sender;
tb.BorderBrush = new SolidColorBrush(Colors.LightGray);
}
private void button_Click(object sender, RoutedEventArgs e)
{
Data["UserNameData"] = NameBox.Text;
NavigationService.Navigate(new Uri("/Test2.xaml", UriKind.Relative));
}
}
-->Page2:
using myProject.Model;
public partial class Test2 : PhoneApplicationPage
{
IsolatedStorageSettings Data = IsolatedStorageSettings.ApplicationSettings;
UserData ObjUserData = new UserData();
public Test2()
{
InitializeComponent();
this.Loaded += Test2_Loaded;
}
private void Test2_Loaded(object sender, RoutedEventArgs e)
{
if (Data.Contains("UserNameData"))
{
StckUserDetailsUI.DataContext = ObjUserData;
}
}
}
<StackPanel Name="StckUserDetailsUI" Grid.Row="0" Margin="12,17,0,28" Grid.ColumnSpan="2">
<TextBlock Text="Your Details :" Foreground="White" FontSize="30" TextDecorations="Underline"/>
<TextBlock FontSize="40" Name="TxtUserName" Text="{Binding UserName}" Foreground="White"/>
</StackPanel>
--->UserData.Cs: (in in the file /Model)
class UserData
{
public string UserName { get; set; }
}
note:
I work in windows phone 8.1 silverlight

You set the DataContext to ObjUserData but you never put anything for ObjUserData.UserName, hence it comes back as blank.

Binding to DependencyProperty doesn't update LongListSelector items as expected

I have one UserControl LetterInRowUserControl with LongListSelector and ItemTemplate in xaml part
<UserControl>
...
<UserControl.Resources>
<DataTemplate x:Key="itemTemplate">
<local:LetterControl x:Name="letterControl" VerticalAlignment="Top" Width="50" Letter="{Binding}"/>
</DataTemplate>
</UserControl.Resources>
<Grid x:Name="LayoutRoot">
<phone:LongListSelector x:Name="lls" LayoutMode="List" ItemTemplate="{StaticResource itemTemplate}" />
</Grid>
</UserControl>
cs part:
public partial class LetterInRowUserControl : UserControl
{
public LetterInRowUserControl()
{
InitializeComponent();
LetterControl.TextChanged += (o, ev) =>
{
var conv = new StringToListConverter();
ContainsLetters = (string)conv.ConvertBack(lls.ItemsSource, typeof(string), null, CultureInfo.CurrentCulture);
};
}
public static readonly DependencyProperty ContainsLettersProperty =
DependencyProperty.Register("ContainsLetters", typeof (string), typeof (LetterInRowUserControl), new PropertyMetadata(default(string),
(o, args) =>
{
var control = (LetterInRowUserControl) o;
var conv = new StringToListConverter();
control.lls.ItemsSource = (ObservableCollection<string>)conv.Convert(args.NewValue, typeof(string), null, CultureInfo.CurrentCulture);
}));
public string ContainsLetters
{
get
{
return (string) GetValue(ContainsLettersProperty);
}
set
{
SetValue(ContainsLettersProperty, value);
}
}
}
then I have second Usercontrol - LetterControl which is inside itemstemplate of LetterInRowUserControl
xaml part:
<UserControl>
...
<Grid x:Name="LayoutRoot">
<Grid>
<Button x:Name="hidden" Height="0" Width="0"/>
<TextBox x:Name="textBox"
TextWrapping="Wrap" VerticalAlignment="Top" Height="84" Margin="-12" FontFamily="Segoe WP Semibold" FontSize="33.333" TextAlignment="Center" GotFocus="textBox_GotFocus" LostFocus="textBox_LostFocus" MaxLength="1" TextChanged="textBox_TextChanged"/>
</Grid>
</Grid>
</UserControl>
and cs part:
public partial class LetterControl : UserControl
{
public static event TextChangedEventHandler TextChanged;
public static readonly DependencyProperty LetterProperty =
DependencyProperty.Register("Letter", typeof(string), typeof(LetterControl), new PropertyMetadata(default(string),
(o, args) =>
{
var control = (LetterControl)o;
control.textBox.Text = (string)args.NewValue;
}));
public string Letter
{
get { return (string)GetValue(LetterProperty); }
set
{
SetValue(LetterProperty, value);
}
}
public LetterControl()
{
InitializeComponent();
}
private void textBox_GotFocus(object sender, RoutedEventArgs e)
{
textBox.SelectAll();
}
private void textBox_LostFocus(object sender, RoutedEventArgs e)
{
textBox.Text = textBox.Text.ToUpper();
}
private void textBox_TextChanged(object sender, TextChangedEventArgs e)
{
SetValue(LetterProperty,textBox.Text);
if(textBox.Text.Length>=1)
hidden.Focus();
if (TextChanged != null) TextChanged.Invoke(sender, e);
}
}
Basically there are two UserControls: LetterInRowUserControl and LetterControl.
LetterInRowUserControl has LongListSelector with LetterControl inside its ItemTemplate.
The problem is that if I change Property Letter from inside LetterControl, it doesn't affect ItemSource in LongListSelector in LetterInRowUserControl. Conversely (if I change ItemSource directly) it works without problems.
/intended to one Windows Phone 8 App
... something like listbox with textboxes of one letter - problem is that if I edit a letter ItemSource of listbox doesn't change.
EDIT: After hard trying I have succeeded. And my code is working. Main problem was that I was using ObservableCollection<string> and not ObservableCollection<CustomObjectWithINotifyPropChangedImplementation>. So the value wasn't automatically changed (ObservableCollection did not fulfill its function).

Change main window implementation to user control

I need to replace the following code usercontrol instead of main window (of course the main window is just calling to the userControl),while doing that I have the following problem.
Currently I tried to add the following code like in the main window in the
constructor of the usercontrol after the
public partial class UserControl: UserControl
{
private static MappingViewModelView _modelViewInstance;
public UserControl()
{
InitializeComponent();
_modelViewInstance = new MappingViewModelView();
DataContext = _modelViewInstance;
var source = Resources["source"] as CollectionViewSource;
if (source != null)
source.Source = _modelViewInstance.UserList;
ListBox.SelectionChanged += listbox_SelectionChanged;
But now in the user control there is no event SelectionChanged for list box (using the intlisense) just ListBox.SelectionChangedEvent which is not fit the original solution from the main window which is
ListBox.SelectionChanged += listbox_SelectionChanged;
error which is given if i put the exact code is: Cannot access non-static event 'SelectionChanged' in static context
Any idea why the list box behave different in the user control?
public partial class MainWindow : Window
{
public ObservableCollection<User> _UsersList = new ObservableCollection<User>();
private readonly Dictionary<string, string> _mapping = new Dictionary<string, string>();
private const string DRAG_SOURCE = "DragSource";
public MainWindow()
{
InitializeComponent();
_UsersList.Add(new User { Name = "Jhon" });
_UsersList.Add(new User { Name = "Mike" });
_UsersList.Add(new User { Name = "Alex" });
_UsersList.Add(new User { Name = "Darl" });
CollectionViewSource source = this.Resources["source"] as CollectionViewSource;
source.Source = _UsersList;
ListBox.SelectionChanged += listbox_SelectionChanged;
DataObject.AddCopyingHandler(text1, DragCopy);
DataObject.AddCopyingHandler(text2, DragCopy);
}
public ObservableCollection<User> UserList
{
get { return _UsersList; }
}
private void listbox_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
if (e.AddedItems.Count == 1)
{
if (ListBox.SelectedItems.Count > 0)
{
var mySelectedItem = ListBox.SelectedItem as User;
if (mySelectedItem != null)
{
DragDrop.DoDragDrop(ListBox, mySelectedItem,
DragDropEffects.Copy | DragDropEffects.Move);
}
}
}
}
private void DropText_PreviewDragEnter(object sender, DragEventArgs e)
{
e.Effects = DragDropEffects.None;
}
private void DropText_PreviewDrop(object sender, DragEventArgs e)
{
var textbox = (TextBox)sender;
if (!(textbox.Text.Length > 0))
{
DataObject data = e.Data as DataObject;
User user = data.GetData(typeof(User)) as User;
textbox.Tag = user;
var name = user.Name;
textbox.Text += name;
textbox.Focus();
textbox.CaretIndex = textbox.Text.Length;
e.Handled = true;
var remove = _UsersList.Remove((User)ListBox.SelectedItem);
if (!_mapping.ContainsKey(textbox.Name))
_mapping.Add(textbox.Name, name);
}
e.Handled = true;
}
private void DropText_PreviewDragOver(object sender, DragEventArgs e)
{
e.Handled = true;
}
private void ListBox_Drop(object sender, DragEventArgs e)
{
DataObject data = e.Data as DataObject;
if (data != null)
{
User user = data.GetData(typeof(User)) as User;
if (user != null && !_UsersList.Contains(user))
_UsersList.Add(user);
}
TextBox txtBox = e.Data.GetData(DRAG_SOURCE) as TextBox;
if (txtBox != null)
{
if (_mapping.ContainsKey(txtBox.Name))
_mapping.Remove(txtBox.Name);
txtBox.Dispatcher.BeginInvoke((Action)(() => { txtBox.Text = string.Empty; }), System.Windows.Threading.DispatcherPriority.Normal);
}
e.Handled = true;
}
private void DragCopy(object sender, DataObjectCopyingEventArgs e)
{
if (e.IsDragDrop)
{
e.CancelCommand();
TextBox txtBox = sender as TextBox;
if (txtBox != null && txtBox.Tag != null)
{
DataObject dataObject = new DataObject(txtBox.Tag);
dataObject.SetData(DRAG_SOURCE, txtBox);
DragDrop.DoDragDrop(sender as DependencyObject, dataObject, DragDropEffects.Move | DragDropEffects.Copy);
}
e.Handled = true;
}
}
private void DropText_TextChanged(object sender, TextChangedEventArgs e)
{
TextBox txtBox = sender as TextBox;
if (txtBox.Text == string.Empty)
{
User user = txtBox.Tag as User;
if(user != null && !_UsersList.Contains(user))
_UsersList.Add(user);
if (_mapping.ContainsKey(txtBox.Name))
_mapping.Remove(txtBox.Name);
}
}
}
ListBox x:Name="ListBox" HorizontalAlignment="Left" Height="115"
VerticalAlignment="Top" Width="150" ItemsSource="{Binding Source={StaticResource source}}"
DisplayMemberPath="Name"
AllowDrop="True" Drop="ListBox_Drop" />
<Window.Resources>
<CollectionViewSource x:Key="source">
</CollectionViewSource>
</Window.Resources>
<TextBox x:Name="text1"
AcceptsReturn="True"
AllowDrop="True"
PreviewDragEnter="DropText_PreviewDragEnter"
PreviewDrop="DropText_PreviewDrop"
PreviewDragOver="DropText_PreviewDragOver"
TextChanged="DropText_TextChanged"
Grid.Column="1"
HorizontalAlignment="Left" Height="23" TextWrapping="Wrap"
VerticalAlignment="Top" Width="120"/>
<TextBox x:Name="text2"
AcceptsReturn="True"
AllowDrop="True"
PreviewDragEnter="DropText_PreviewDragEnter"
PreviewDrop="DropText_PreviewDrop"
PreviewDragOver="DropText_PreviewDragOver"
TextChanged="DropText_TextChanged"
Grid.Column="1"
HorizontalAlignment="Left" Height="23" TextWrapping="Wrap"
VerticalAlignment="Top" Width="120"/>

If you moved the ListBox to the UserControl, the most likely reasen is that - maybe by accident - the name was changed in the process.
The error message points in this direction as it recognizes ListBox as the type and not as the name of a concrete instance of a ListBox on the UserControl.

how to access a textbox in a grid in a stackpanel

I have the following code:
<StackPanel x:Name="ContentStackPanel">
<Grid>
<TextBlock Text="Min Value" />
<TextBox Text="{Binding MinValue}" />
</Grid>
<Grid>
<TextBlock Text="Max Value" />
<TextBox Text="{Binding MinValue}" />
</Grid>
</StackPanel>
I want to add a button so that I can clear the text in both TextBoxes. This code doesn't work
private void ClearAllClick(object sender, RoutedEventArgs e)
{
foreach (TextBox tb in ContentStack.Children)
{
tb.Text = String.Empty;
}
}
how do I access the textbox inside the grid of ContentStackPanel?

The Children property only gives you immediate children, not all descendants. You could write a helper method to traverse the tree:
private void ClearAllClick(object sender, RoutedEventArgs e)
{
ClearTextChildren(ContentStackPanel);
}
private void ClearTextChildren((Panel container)
{
foreach (var element in container.Children)
{
if (element is TextBox)
((TextBox)element).Text = String.Empty;
else if (element is Panel)
ClearChildren((Panel)element);
}
}
An alternative approach (probably better, since it's fragile to traverse UI trees in code) would be to use a Command implementation on the button, instead of a click handler. This will allow you to clear the view-model properties instead of the text boxes themselves.
<Button x:Name="ClearAll" Command="{Binding ClearAllCommand}" />
"ClearAllCommand" should be in the same place as "MinValue" and "MaxValue":
public ICommand ClearAllCommand { get; private set; }
Using a standard DelegateCommand implementation:
ClearAllCommand = new DelegateCommand(arg => {
MinValue = null;
MaxValue = null;
});

Editable Listbox of textboxes in Silverlight

My aim is to be able to add/ edit/delete items to a listbox. I have created a listbox of textboxes in the following way. I am able to display data but I am not able to edit data. Can someone help me modify the code so that I can achieve this functionality.
<ListBox Name="lbDemoBox" ItemsSource="{Binding testList}" Grid.Column="0" Grid.Row="0" SelectionChanged="lbDemoBox_SelectionChanged">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Vertical">
<TextBox Text="{Binding Path=.}" KeyDown="TextBox_KeyDown" KeyUp="TextBox_KeyUp" GotFocus="TextBox_GotFocus"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
Here is the code behind
public partial class MainPage : UserControl
{
private string focusedString { get; set; }
public MainPage()
{
InitializeComponent();
}
private void Window_Loaded(object sender, RoutedEventArgs e)
{
LayoutRoot.DataContext = new ViewModel();
}
private void TextBox_KeyDown(object sender, KeyEventArgs e)
{
if (e.Key == Key.Enter && (Keyboard.Modifiers & (ModifierKeys.Shift)) == ModifierKeys.Shift)
{
(lbDemoBox.ItemsSource as ObservableCollection<string>).Add(string.Empty);
}
}
private void TextBox_KeyUp(object sender, KeyEventArgs e)
{
if (e.Key == Key.Delete)
{
int index = (lbDemoBox.ItemsSource as ObservableCollection<string>).IndexOf(focusedString);
(lbDemoBox.ItemsSource as ObservableCollection<string>).RemoveAt(index);
}
}
private void TextBox_GotFocus(object sender, RoutedEventArgs e)
{
focusedString = (sender as TextBox).Text;
}
private void lbDemoBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
}
}
public class ViewModel
{
public ObservableCollection<string> testList
{
get { return new ObservableCollection<string> { "Item1", "Item2", "Item3" }; }
}
}

Try this:
<TextBox Text="{Binding Path=YourProperty, Mode=TwoWay}" />