I have a TextBox that I am setting the focus on using an attached property bound to a property of the view model. The attached property calls "UIElement.Focus()" to set the focus. The problem is when the TextBox receives focus in this manner the "GotFocus" event doesn't fire. I am using Caliburn.Micro's Message.Attach to handle the event. Any ideas?
Here is the TextBox.
<TextBox x:Name="Test"
Grid.Column="0"
Text="{Binding Test, Converter={StaticResource TestToStringConverter}}"
AttachedProperties:FocusExtension.IsFocused="{Binding IsTestFocused}"
cal:Message.Attach="[Event GotFocus] = [Action OnGotFocus($eventargs)]; />
Here is the Attached Property (found on SO).
public static class FocusExtension
{
public static bool GetIsFocused(DependencyObject obj)
{
return (bool) obj.GetValue(IsFocusedProperty);
}
public static void SetIsFocused(DependencyObject obj, bool value)
{
obj.SetValue(IsFocusedProperty, value);
}
public static readonly DependencyProperty IsFocusedProperty =
DependencyProperty.RegisterAttached("IsFocused", typeof (bool), typeof (FocusExtension),
new UIPropertyMetadata(false, OnIsFocusedPropertyChanged));
private static void OnIsFocusedPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var uie = (UIElement)d;
if ((bool)e.NewValue)
{
uie.Focus();
}
}
}
I have tried this myself, and am able to replicate the issue. I'm not quite sure why this happens, it may have something to do with the user control's (i.e. the views) lifecycle. One option could be to extend your attached property so that it invokes a verb on your view model at the point at which it calls uie.Focus().
The name of the verb could be a dependency property on your FocusExtension attached property, and could be set in the view.
Related
I wanted to create a textbox that can search for files and also keeps track of previously used files. So I made a user control with a DependecyProperty that should give me the current text of the textbox and a button. But everytime I try to bind to the DependencyProperty, the property that binds to it remains empty. In short, the control looks like this:
<UserControl
<!-- ... -->
x:Name="PTB">
<AutoSuggestBox x:Name="SearchBox"
Text="{Binding ElementName=PTB, Path=FilePath, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />
<Button Command="{Binding PickFileCommand}" />
</UserControl
I have this simple ViewModel for the user control
public string FilePath
{
get => _filePath;
set => SetProperty(ref _filePath, value);
}
public async Task PickFile()
{
// ...
}
and this code-behind for the user control
public readonly static DependencyProperty FilePathProperty =
DependencyProperty.Register("FilePath", typeof(string), typeof(PathTextBox), new PropertyMetadata("", new PropertyChangedCallback(OnTextChanged)));
public string FilePath
{
get => (string)GetValue(FilePathProperty);
set => SetValue(FilePathProperty, value);
}
private static void OnTextChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs e)
{
if (dependencyObject is PathTextBox ptb && e.NewValue is string s)
{
ptb.SearchBox.Text = s;
ptb.FilePath = s;
}
}
And when I try to use it like this in my MainPage.xaml:
<customcontrols:PathTextBox x:Name="SearchBox"
KeyUp="SearchBox_KeyUp"
FilePath="{Binding ScriptFilePath, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>
and MainPage.xaml.cs
private async void SearchBox_KeyUp(object sender, KeyRoutedEventArgs e)
{
if (e.Key == VirtualKey.Enter)
{
await ViewModel.OpenSqlFile(ViewModel.ScriptFilePath);
}
}
then ViewModel.ScriptFilePath remains empty, even though I did bind to it. I tried a couple of different things with x:Bind etc., but I couldn't find a way to cleanly implement it in MVVM. I'm using the CommunityToolkit.Mvvm library, if that helps. Any ideas?
From your code, I assume that you have the ViewModel in MainPage.xaml.cs. Then you need to add ViewModel to you binding code.
<customcontrols:PathTextBox
x:Name="SearchBox"
KeyUp="SearchBox_KeyUp"
FilePath="{Binding ViewModel.ScriptFilePath, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>
or even better, use x:Bind ViewModel.ScriptFilePath.
I defined a custom loading spinner UserControl in a WPF UserContol library.
It has one dependency property:
public string SpinnerSourcePath { get => _spinner.Source.ToString(); set => _spinner.Source = (ImageSource)new ImageSourceConverter().ConvertFromString(value); }
public static readonly DependencyProperty SpinnerSourcePathProperty =
DependencyProperty.Register(nameof(SpinnerSourcePath), typeof(string), typeof(Spinner));
where _spinner is the Image.
(I tried it directly with ImageSource class but no dice)
The xaml looks like this:
<Image x:Name="_spinner" RenderTransformOrigin="0.5 0.5">
<SomeStyleToMakeItRotate.../>
</Image>
and I use it by defining it like:
<c:Spinner SpinnerSourcePath="/Test;component/_Resources/loading.png"/>
(The project name is Test, the Spinner control resides in a different project), nothing is displayed.
However, if I add the Source property directly in the Spinner definition:
<Image x:Name="_spinner" Source="/Test;component/_Resources/loading.png" RenderTransformOrigin="0.5 0.5">
<SomeStyleToMakeItRotate.../>
</Image>
it shows correctly...
This leads me to believe that the dependency property is wrong, but how ?
E1:
After trying to do the same steps on a different control it stopped working again.
This time I have a DP:
public static readonly DependencyProperty ValidationFunctionProperty =
DependencyProperty.Register(nameof(ValidationFunction), typeof(Func<string, bool>), typeof(ValidatedTextBox), new PropertyMetadata(OnAssignValidation));
public Func<string, bool> ValidationFunction {
get => (Func<string, bool>)GetValue(ValidationFunctionProperty);
set => SetValue(ValidationFunctionProperty, value);
}
private static void OnAssignValidation(DependencyObject d, DependencyPropertyChangedEventArgs e) {
Debugger.Break();
}
Control usage:
<c:ValidatedTextBox x:Name="valid"
Text="Test"
ValidationFunction="{Binding Validation, RelativeSource={RelativeSource AncestorType=UserControl}, Converter={StaticResource test}}"/>
The converter is just a Debugger.Break() and return original
And finally the RelativeSource control is my MainWindow
public MainWindow() {
InitializeComponent();
}
public Func<string,bool> Validation => (s) => true;
(There is a problem with the Text DP as well, but I think I can solve that one on my own)
E2
Ok Pro problem was the RelativePath pointing to UserControl but it was placed in a Window
Your dependency property declaration is wrong, because the get/set methods of the CLR property wrapper must call the GetValue and SetValue methods of the DependencyObject base class (and nothing else).
Besides that, the property should also use ImageSource as its type:
public static readonly DependencyProperty SpinnerSourceProperty =
DependencyProperty.Register(
nameof(SpinnerSource), typeof(ImageSource), typeof(Spinner));
public ImageSource SpinnerSource
{
get { return (ImageSource)GetValue(SpinnerSourceProperty); }
set { SetValue(SpinnerSourceProperty, value); }
}
The Image element in the UserControl's XAML would use the property like this:
<Image Source="{Binding SpinnerSource,
RelativeSource={RelativeSource AncestorType=UserControl}}"/>
i have created a wpf user control with a text box and a combo box.
for accessing the text property of the text box i have used the below code
public static readonly DependencyProperty TextBoxTextP = DependencyProperty.Register(
"TextBoxText", typeof(string), typeof(TextBoxUnitConvertor));
public string TextBoxText
{
get { return txtValue.Text; }
set { txtValue.Text = value; }
}
in another project i have used the control and bind the text as below:
<textboxunitconvertor:TextBoxUnitConvertor Name="wDValueControl" TextBoxText="{Binding _FlClass.SWa_SC.Value , RelativeSource={RelativeSource AncestorType=Window}, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}" Width="161" Height="28" HorizontalAlignment="Left" VerticalAlignment="Top"/>
i am certain that the class that is used for binding is properly working because when i used it to bing with a text box directly in my project it works properly but when i bind it to the text property of textbox in usercontrol it brings null and the binding does not work.
can any one help me?
Your dependency property declaration is wrong. It has to look like shown below, where the getter and setter of the CLR property wrapper call the GetValue and SetValue methods:
public static readonly DependencyProperty TextBoxTextProperty =
DependencyProperty.Register(
"TextBoxText", typeof(string), typeof(TextBoxUnitConvertor));
public string TextBoxText
{
get { return (string)GetValue(TextBoxTextProperty); }
set { SetValue(TextBoxTextProperty, value); }
}
In the XAML of your UserControl, you would bind to the property like this:
<TextBox Text="{Binding TextBoxText,
RelativeSource={RelativeSource AncestorType=UserControl}}" />
If you need to get notified whenever the TextBoxText property changes, you could register a PropertyChangedCallback with PropertyMetadata passed to the Register method:
public static readonly DependencyProperty TextBoxTextProperty =
DependencyProperty.Register(
"TextBoxText", typeof(string), typeof(TextBoxUnitConvertor),
new PropertyMetadata(TextBoxTextPropertyChanged));
private static void TextBoxTextPropertyChanged(
DependencyObject o, DependencyPropertyChangedEventArgs e)
{
TextBoxUnitConvertor t = (TextBoxUnitConvertor)o;
t.CurrentValue = ...
}
You are not creating the dependency property right. Use this code:
public string TextBoxText
{
get { return (string)GetValue(TextBoxTextProperty); }
set { SetValue(TextBoxTextProperty, value); }
}
public static readonly DependencyProperty TextBoxTextProperty =
DependencyProperty.Register("TextBoxText", typeof(string), typeof(TextBoxUnitConvertor), new PropertyMetadata(""));
Then in your custom control Bind the TextBoxText to the value of txtValue.Text
this is my xaml:
<toolkit:AutoCompleteBox Name="signalNameEditor"
ItemsSource="{Binding MySource}"
SelectedItem="{Binding SelectedItem, Mode=TwoWay}"
IsTextCompletionEnabled="True"
FilterMode="StartsWith"
ValueMemberPath="Label"
MinimumPrefixLength="3"
MinimumPopulateDelay="800"
Style="{StaticResource autoCompleteBoxStyle}">
<toolkit:AutoCompleteBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Name="textBlock" Text="{Binding Label}"/>
</StackPanel>
</DataTemplate>
</toolkit:AutoCompleteBox.ItemTemplate>
</toolkit:AutoCompleteBox>
So, how could i get textblock element in my view? I tried this:
var textBlock = signalNameEditor.FindName("textBlock");
but it is wrong. So could you help me with this or redirect me to a proper solution. Thanks in advance.
Thanks for all aswers, that worked
var textBlock = ((StackPanel)signalNameEditor.ItemTemplate.LoadContent()).FindName("textBlock") as TextBlock;
but unfortunately I didn't get the result, that I expected. The question is how to get focus on textbox in autocompletebox, so that when focus is on autocompletebox I could write something there without double clicking.
I thought that I could do something inside my view
public void SetFocus
{
var textBlock = ((StackPanel)signalNameEditor
.ItemTemplate
.LoadContent())
.FindName("textBlock") as TextBlock;
textBlock.Focus();
}
I know that there are a lot of howto examples for setting focus like this one
autocompletebox focus in wpf
but I can't make it work for me. Is there a solution, that I could get without writing AutoCompleteFocusableBox class?
The solution was simplier. Actually i need to set focus on a textbox in a autocompletebox. For this purpose I used style defined as a regular style http://msdn.microsoft.com/ru-ru/library/dd728668(v=vs.95).aspx
After it in my view I could use the following:
public void SetFocus()
{
var textbox = this.editor.Template.FindName("Text", editor) as TextBox;
textbox.Focus();
}
You can Write extension and set custom property for textbox to make it focusable
For example you can write extension class as below
public static class FocusBehavior
{
#region Constants
public static readonly DependencyProperty IsFocusedProperty =
DependencyProperty.RegisterAttached("IsFocused", typeof (bool?),
typeof (FocusBehavior), new FrameworkPropertyMetadata(IsFocusedChanged));
#endregion
#region Public Methods
public static bool GetIsFocused(DependencyObject obj)
{
return (bool) obj.GetValue(IsFocusedProperty);
}
public static void SetIsFocused(DependencyObject obj, bool value)
{
obj.SetValue(IsFocusedProperty, value);
}
#endregion
#region Event Handlers
private static void IsFocusedChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var uie = (UIElement) d;
if ((bool) e.NewValue)
uie.Dispatcher.BeginInvoke(DispatcherPriority.Input, new ThreadStart(() => Keyboard.Focus(uie)));
}
#endregion Event Handlers
}
Then in xaml as below:
<UserControl xmlns:behaviours="clr-namespace:Example.Views.Behaviours">
<TextBox TextWrapping="Wrap" Text="TextBox" behaviours:FocusBehavior.IsFocused={Binding IsFocused}/>
I hope that answeres your question
Does anyone know of a way to change the style of an expander if a IDataError validation occurs in a control held within the expander. E.g.
<Expander Header="Details">
<TextBox Text="{Binding Brand.DESCRIPTION,
UpdateSourceTrigger=LostFocus,
ValidatesOnDataErrors=True}"/>
</Expander>
So if the textbox has an error the style of my expander will change (go red maybe).
I'm looking to make this as generic as possible so without binding to each control within the expander manually if possible.
You could make use of the Attached Event Validation.Error (which is raised everytime a validation error is added or removed) through an Attached Behavior. To make this work you need to add NotifyOnValidationError=True to the bindings.
This Attached Behavior, ChildValidation, subscribes to the Validation.Error event for the Expander which is bubbled up if NotifyOnValidationError is set to True on the bindings. Since several Controls may be located within the Expander it also need to keep track of the count of Validation Errors that's currently active to determine if a Red Border should be displayed or not. It could look like this
Xaml
<Expander Header="Details"
behaviors:ChildValidationBehavior.ChildValidation="True">
<TextBox Text="{Binding Brand.DESCRIPTION,
UpdateSourceTrigger=LostFocus,
ValidatesOnDataErrors=True,
NotifyOnValidationError=True}"/>
</Expander>
ChildValidationBehavior
public static class ChildValidationBehavior
{
private static readonly DependencyProperty ErrorCountProperty =
DependencyProperty.RegisterAttached("ErrorCount",
typeof(int),
typeof(ChildValidationBehavior));
private static void SetErrorCount(DependencyObject element, int value)
{
element.SetValue(ErrorCountProperty, value);
}
private static int GetErrorCount(DependencyObject element)
{
return (int)element.GetValue(ErrorCountProperty);
}
public static readonly DependencyProperty ChildValidationProperty =
DependencyProperty.RegisterAttached("ChildValidation",
typeof(bool),
typeof(ChildValidationBehavior),
new UIPropertyMetadata(false, OnChildValidationPropertyChanged));
public static bool GetChildValidation(DependencyObject obj)
{
return (bool)obj.GetValue(ChildValidationProperty);
}
public static void SetChildValidation(DependencyObject obj, bool value)
{
obj.SetValue(ChildValidationProperty, value);
}
private static void OnChildValidationPropertyChanged(DependencyObject dpo,
DependencyPropertyChangedEventArgs e)
{
Control control = dpo as Control;
if (control != null)
{
if ((bool)e.NewValue == true)
{
SetErrorCount(control, 0);
Validation.AddErrorHandler(control, Validation_Error);
}
else
{
Validation.RemoveErrorHandler(control, Validation_Error);
}
}
}
private static void Validation_Error(object sender, ValidationErrorEventArgs e)
{
Control control = sender as Control;
if (e.Action == ValidationErrorEventAction.Added)
{
SetErrorCount(control, GetErrorCount(control)+1);
}
else
{
SetErrorCount(control, GetErrorCount(control)-1);
}
int errorCount = GetErrorCount(control);
if (errorCount > 0)
{
control.BorderBrush = Brushes.Red;
}
else
{
control.ClearValue(Control.BorderBrushProperty);
}
}
}