I have a little problem here. I've created custom TreeView using RadTreeView. It all works nice, but I've encountered an obstacle. I've set DependencyProperty for SelectedItem in TreeView. I nest my control in View, bind property to SelectedItem in TwoWay mode, but bound property won't update, it's null all the time, despite DependencyProperty value being set.
Here's tree xaml:
<Grid xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'
xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
xmlns:sdk='http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk'
xmlns:telerik='http://schemas.telerik.com/2008/xaml/presentation' x:Name='this' >
<Grid.Resources>
<DataTemplate x:Key='ChildTemplate'>
<TextBlock Text='{Binding Path=ChildPath}' Margin='5,0' />
</DataTemplate>
<telerik:HierarchicalDataTemplate x:Key='NameTemplate' ItemsSource='{Binding ChildrenCollectionPath}' ItemTemplate='{StaticResource ChildTemplate}'>
<TextBlock Text='{Binding Path=ParentPath }' Padding='7'/>
</telerik:HierarchicalDataTemplate>
</Grid.Resources>
<telerik:RadTreeView x:Name='rtvTreeView' Padding='5' BorderThickness='0' IsEditable='False' IsLineEnabled='True' IsExpandOnDblClickEnabled='False' ItemTemplate='{StaticResource NameTemplate}' />
</Grid>
Below is way I nest the control in View:
<windows:TreeViewReuse CollectionSource="{Binding SitesCollectionWithAddress}" ParentPath="Napis" Grid.Column="0" BorderThickness="2" SelectedItemD="{Binding SelectedSide, ElementName=this, UpdateSourceTrigger=Explicit, Mode=TwoWay}" ChildPath="FullAddress" ChildrenCollectionPath="AdresyStrony" BorderBrush="Red" DoubleClickCommand="{Binding TreeViewDoubleClick}">
</windows:TreeViewReuse>
And here's Tree's code behind in parts:
public partial class TreeViewReuse : UserControl
{
static Telerik.Windows.FrameworkPropertyMetadata propertyMetaData = new Telerik.Windows.FrameworkPropertyMetadata(null,
Telerik.Windows.FrameworkPropertyMetadataOptions.BindsTwoWayByDefault, new PropertyChangedCallback(SelectedItemChangedCallback));
public object SelectedItemD
{
get { return GetValue(SelectedItemDProperty); }
set { SetValue(SelectedItemDProperty, value); }
}
public static readonly DependencyProperty SelectedItemDProperty =
DependencyProperty.Register("SelectedItemD", typeof(object), typeof(TreeViewReuse), propertyMetaData);
public TreeViewReuse()
{
InitializeComponent();
Loaded += new RoutedEventHandler(TreeViewReuse_Loaded);
}
void treeView_SelectionChanged(object sender, Telerik.Windows.Controls.SelectionChangedEventArgs e)
{
SelectedItemD = _treeView.SelectedItem;
}
static private void SelectedItemChangedCallback(DependencyObject dp, DependencyPropertyChangedEventArgs e)
{
}
Does anyone have an idea why property bound to SelectedItemD does not update? I don't care about setting tree's selected item from it, I only want to set it to selected item.
Here's property:
public StronaSprawy SelectedSide
{
get
{
return _selectedSide;
}
set
{
_selectedSide = value;
}
}
Your Dependency Property looks fine.. all except for that Telerik.Windows.FrameworkPropertyMetadata instance.
Silverlight does not support setting meta data options, so I cant think how the Telerik implementation will achieve that. It is possible that Telerik have their own DP implementation, or even that this type of property meta data only works with their controls.
Try using the standard System.Windows.PropertyMetaData type instead and see if that works for you.
I have created a user control like numeric updown as follows
<StackPanel Orientation="Horizontal" VerticalAlignment="Top" >
<TextBox x:Name="InputTextBox" Grid.Row="0" Grid.Column="0" Grid.RowSpan="1"
Style="{StaticResource NumericUpDownTextBoxStyle}"
KeyDown="InputTextBox_KeyDown"
KeyUp="InputTextBox_KeyUp"
GotFocus="InputTextBox_GotFocus"
LostFocus="InputTextBox_LostFocus"
MouseWheel="InputTextBox_MouseWheel"
MouseEnter="InputTextBox_MouseEnter"
LayoutUpdated="InputTextBox_LayoutUpdated"
Text="{Binding Path=ControlValue, Mode=TwoWay,ValidatesOnDataErrors=True,ValidatesOnExceptions=True,NotifyOnValidationError=True}"/>
</StackPanel>
I have bind a ViewModel to this control where I Set ControlValue property to TextBox property of the user control template textbox.
Everthing works fine at a control level. I have exposed from usercontrol.
public static readonly DependencyProperty MaximumValueProperty;
public static readonly DependencyProperty MinimumValueProperty;
public static readonly DependencyProperty StepValueProperty;
public static readonly DependencyProperty TextValueProperty;
My Properties are
public double Maximum
{
get
{
return (double)GetValue(MaximumValueProperty);
}
set
{
SetValue(MaximumValueProperty, value);
this.ViewModel.Maximum = this.Maximum;
}
}
public double Minimum
{
get
{
return (double)GetValue(MinimumValueProperty);
}
set
{
SetValue(MinimumValueProperty, value);
this.ViewModel.Minimum = this.Minimum;
}
}
public double Step
{
get
{
return (double)GetValue(StepValueProperty);
}
set
{
SetValue(StepValueProperty, value);
this.ViewModel.Step = this.Step;
}
}
public double TextValue
{
get
{
return (double)GetValue(TextValueProperty);
}
set
{
SetValue(TextValueProperty, value);
this.ViewModel.ControlValue = Convert.ToString(value);
}
}
Initialization of the property.
static NumericUpDown()
{
MaximumValueProperty = DependencyProperty.Register("Maximum", typeof(double), typeof(NumericUpDown), new PropertyMetadata(null));
MinimumValueProperty = DependencyProperty.Register("Minimum", typeof(double), typeof(NumericUpDown), new PropertyMetadata(null));
StepValueProperty = DependencyProperty.Register("Step", typeof(double), typeof(NumericUpDown), new PropertyMetadata(null));
TextValueProperty = DependencyProperty.Register("TextValue", typeof(double), typeof(NumericUpDown), new PropertyMetadata(null));
}
My Usercontrol implementation in the MainPage.xaml page as follows
<local:NumericUpDown Maximum="28" Minimum="-28" Step="0.25" TextValue="{Binding ElementName=FranePrice, Path=DataContext.FranePrice}"></local:NumericUpDown>
Where I have another ViewModel which i bind to the XAML page and there is a Property in the ViewModel which i bind to the TextValue property of the Usercontrol.
FramePrice is property in the View model that i bind to the TextValue property of the user control
and Main page XAML is
<UserControl x:Class="DatePicker.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:DatePicker"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="400" xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk">
<Grid x:Name="LayoutRoot" Background="White">
<StackPanel Orientation="Vertical">
<local:NumericUpDown Maximum="28" Minimum="-28" Step="0.25" TextValue="{Binding ElementName=FranePrice, Path=DataContext.FranePrice}"></local:NumericUpDown>
<Button Content="Show Date" Height="23" Name="button1" VerticalAlignment="Top" Width="75" Click="button1_Click"/>
</StackPanel>
</Grid>
This View model of the page where i used user control. On click event i showing TextValue to user.
public class MainPageViewModel : EntityViewModel
{
public MainPageViewModel()
{
}
private double framePrice;
public Double FramePrice
{
get
{
return framePrice;
}
set
{
framePrice = value;
PropertyChangedHandler("FramePrice");
}
}
}
When I change the TextValue in the User control it doesnot change in the FramePrice property of the page viewmodel.
Is anything wrong in the code.???
As per Luke Woodward's post I have updated code as follows
public static readonly DependencyProperty MaximumValueProperty;
public static readonly DependencyProperty MinimumValueProperty;
public static readonly DependencyProperty StepValueProperty;
public static readonly DependencyProperty TextValueProperty;
public static double Max;
public static double Min;
public static double Stp;
public static double Val;
public double Maximum
{
get
{
return (double)GetValue(MaximumValueProperty);
}
set
{
SetValue(MaximumValueProperty, value);
}
}
public double Minimum
{
get
{
return (double)GetValue(MinimumValueProperty);
}
set
{
SetValue(MinimumValueProperty, value);
}
}
public double Step
{
get
{
return (double)GetValue(StepValueProperty);
}
set
{
SetValue(StepValueProperty, value);
}
}
public double TextValue
{
get
{
return (double)GetValue(TextValueProperty);
}
set
{
SetValue(TextValueProperty, value);
}
}
static NumericUpDown()
{
MaximumValueProperty = DependencyProperty.Register("Maximum", typeof(double), typeof(NumericUpDown), new PropertyMetadata(new PropertyChangedCallback(onMaximumValueChanged)));
MinimumValueProperty = DependencyProperty.Register("Minimum", typeof(double), typeof(NumericUpDown), new PropertyMetadata(new PropertyChangedCallback(onMinimumValueChanged)));
StepValueProperty = DependencyProperty.Register("Step", typeof(double), typeof(NumericUpDown), new PropertyMetadata(new PropertyChangedCallback(onStepValueChanged)));
TextValueProperty = DependencyProperty.Register("TextValue", typeof(double), typeof(NumericUpDown), new PropertyMetadata(new PropertyChangedCallback(onTextValueChanged)));
}
private static void onStepValueChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
Stp = (double)e.NewValue;
}
private static void onMinimumValueChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
Min = (double)e.NewValue;
}
private static void onMaximumValueChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
Max = (double)e.NewValue;
}
private static void onTextValueChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
Val = (double)e.NewValue;
}
Then i accessed Max, Min , Stp and Val property in user control's view model to perform my logic.
and XAML code is follows
<local:NumericUpDown x:Name="ctlUpDown" Maximum="28" Minimum="-28" Step="0.25" TextValue="{Binding Path=FramePrice}"></local:NumericUpDown>
and XAML of user control
<StackPanel Margin="5" Orientation="Horizontal" VerticalAlignment="Center">
<TextBox x:Name="InputTextBox" Grid.Row="0" Grid.Column="0" Grid.RowSpan="1"
Height="23" VerticalAlignment="Top"
Width="50" TextAlignment="Center"
KeyDown="InputTextBox_KeyDown"
KeyUp="InputTextBox_KeyUp"
GotFocus="InputTextBox_GotFocus"
LostFocus="InputTextBox_LostFocus"
MouseWheel="InputTextBox_MouseWheel"
MouseEnter="InputTextBox_MouseEnter"
Text="{Binding Path=TextValue, ElementName=ctlUpDown, Mode=TwoWay,ValidatesOnDataErrors=True,ValidatesOnExceptions=True,NotifyOnValidationError=True}"
/>
</StackPanel>
The first thing I noticed wrong about your code was the properties Maximum, Minimum, Step and TextValue. Here's the TextValue property:
public double TextValue
{
get
{
return (double)GetValue(TextValueProperty);
}
set
{
SetValue(TextValueProperty, value);
this.ViewModel.ControlValue = Convert.ToString(value);
}
}
Properties that are backed by a dependency property, such as the four I mentioned above, should ALWAYS look like the following:
public double TextValue
{
get { return (double)GetValue(TextValueProperty); }
set { SetValue(TextValueProperty, value); }
}
In other words, the getter should contain nothing more than a call to GetValue, and the setter should contain nothing more than a call to SetValue.
The reason for this is that when Silverlight changes the value of the TextValue dependency property, it won't do it by using the property above. The values of dependency properties are stored within the Silverlight dependency system, and when Silverlight wants to change the value of one of them, it goes directly to this dependency system. It doesn't call your code at all. Properties like that above are provided only for your convenience, giving you an easy way to access and change the value stored in the dependency property. They will never be called by anything other than your own code.
Generally, if you want a method to be called whenever a dependency property value changes, you need to pass a PropertyChangedCallback in the PropertyMetadata when registering the dependency property. However, I suspect that in your case you won't need to do that.
It seems to me that you have three properties:
the FramePrice property in your view-model class,
the TextValue dependency property of your NumericUpDown user control,
the Text dependency property of the TextBox within your NumericUpDown user control's XAML.
My impression is that you want the FramePrice property in your view-model to always have the same value as the Text property of the TextBox. To do that, you need to bind the FramePrice property to the NumericUpDown's TextValue property, and then bind that to the Text property of the TextBox.
To bind the first two of these properties together, there are a couple of things to change. Firstly, the TextValue property in your <local:NumericUpDown> element should look like
TextValue="{Binding Path=FramePrice}"
The binding {Binding ElementName=FramePrice, Path=DataContext.FramePrice} won't work, because there's no element in your XAML with the attribute x:Name="FramePrice". The value of an ElementName property in a {Binding ...} must match the x:Name of an object in the XAML.
You also need to set up the DataContext for your main page. If your main page view-model object has a zero-argument constructor, one way of doing this is to follow this answer.
To bind the second two properties together, I would:
add an x:Name attribute to the <UserControl> element of your NumericUpDown control (x:Name="ctlUpDown", say),
replace the Text property of the TextBox within your NumericUpDown control with the following:
Text="{Binding Path=TextValue, ElementName=ctlUpDown, Mode=TwoWay, ValidatesOnDataErrors=True, ValidatesOnExceptions=True, NotifyOnValidationError=True}"/>
Once you've done that, you can then remove all of the lines this.ViewModel.SomeProperty = ... from your code-behind class. They're not necessary, and as I've already explained they won't be run when you wanted them to.
Finally, is there a reason you're not using the Silverlight Toolkit's NumericUpDown control?
EDIT 2: Against my better judgement I took a look at one of the two Silverlight projects you uploaded (I ignored the one with _2 in it). It bears very little resemblance to your question.
I can only assume you want the two textboxes (one of which is in a user control) to always have the same value. I was able to do this after making the following changes:
MainPageViewModel.cs: add ClearErrorFromProperty("DPropertyBind"); to the property setter. (Otherwise the validation error never gets cleared.)
MyUserControlWVM.xaml: removed reference to LostFocus event handler, added binding on Text property and added add x:Name attribute to the <UserControl> element. In other words, it now looks like the following:
<UserControl x:Class="DependencyPropertyBinding.MyUserControlWVM"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
x:Name="ctlWVM"
d:DesignHeight="300" d:DesignWidth="205">
<StackPanel Orientation="Horizontal" Width="204" Height="32">
<TextBox x:Name="textbox" Height="30" Width="200" Text="{Binding Path=DProperty, ElementName=ctlWVM, Mode=TwoWay, NotifyOnValidationError=True, ValidatesOnDataErrors=True, ValidatesOnExceptions=True}" />
</StackPanel>
</UserControl>
MyUserControlWVM.xaml.cs: renamed dependency property DependencyPropertyValue to DPropertyProperty (the naming convention is that the static readonly field has the name of the property (in this case DProperty) with Property appended). I also removed the TextBox_LostFocus event handler.
If the code above is accurate you have spelt FramePrice as FranePrice in the binding
The output window should have shown this as a binding error when the page loaded.
it is currently
Binding ElementName=FranePrice, Path=DataContext.FranePrice
should be:
Binding ElementName=FramePrice, Path=DataContext.FramePrice
"With great binding capabilities comes great responsibility" :)
I want a user control called Segmented Panel that contains 3 buttons of which I want to modify their names (Title1/2/3) from a XAML screen.
MainPage XAML:
<local:SegmentedControl HorizontalAlignment="Left" Margin="43,62,0,0" x:Name="segmentedControl1" VerticalAlignment="Top" Title1="ENTER BUTTON NAME HERE" Title2="blah.." Title3="Last Button" Loaded="segmentedControl1_Loaded" />
SegmentedControl XAML.CS:
public static readonly DependencyProperty Title1Property
= DependencyProperty.RegisterAttached("Title1", typeof(String), typeof(StackPanel),
new PropertyMetadata(""));
public static void SetTitle1(UIElement element, String value) {
element.SetValue(Title1Property, value);
}
public static string GetTitle1(UIElement element) {
return (string)element.GetValue(Title1Property);
}
public string Title1 {
get { return GetValue(Title1Property).ToString(); }
set { SetValue(Title1Property, value); }
}
In expression blend I open up the Segmented Panel, choose button1, in Content I tried chosing both Data Context and Element Value, then scrolling down to choose "Title1", but when I compile it, the button's contents never changes.
Can anybody help me out?
as John Gardner suggests, you have to write ...typeof(SegmentedControl) in your dependency property implementation and then one have to bind the property to the appropiate UI element!
For example:
<local:SegmentedControl HorizontalAlignment="Left" Margin="43,62,0,0" x:Name="segmentedControl1" VerticalAlignment="Top" Title1="{Binding Title1}" ... Loaded="segmentedControl1_Loaded" />
I'm trying to register 3 dependency properties on a Window to control it's formatting. I've looked over and over the code but I must be missing something.
public static readonly DependencyProperty TextColorProperty = DependencyProperty.Register("TextColor", typeof(Color), typeof(WinStickyFingers), new PropertyMetadata(Colors.White));
public Color TextColor {
get { return (Color)base.GetValue(TextColorProperty); }
set { base.SetValue(TextColorProperty, value); }
}
public static readonly DependencyProperty BackgroundColorProperty = DependencyProperty.Register("BackgroundColor", typeof(Color), typeof(WinStickyFingers), new PropertyMetadata(Colors.Black));
public Color BackgroundColor {
get { return (Color)base.GetValue(BackgroundColorProperty); }
set {
base.SetValue(BackgroundColorProperty, value);
}
}
<TextBlock DockPanel.Dock="Top" Text="{Binding Name}" Foreground="{Binding TextColor,Converter={StaticResource DebugConverter}}" Background="{Binding Path=BackgroundColor}" />
I'm using Bea Stollnitz's debugging method but my breakpoint isn't even triggered.
What is the DataContext of the TextBlock? How does it know that it is supposed to bind to the properties on your Window?
You need to either set DataContext to the Window instance, or set the Source (or RelativeSource, or ElementName) properties on your bindings. All of these properties exist as a means of resolving the bound object for your Binding. DataContext is a fallback if none of the others is set, but I'm guessing that you haven't set that either.
Say I have a very simple UserControl that - for all intents and purposes - is nothing more than TextBox:
public partial class FooBox : UserControl
{
public static readonly DependencyProperty FooTextProperty =
DependencyProperty.Register("FooText", typeof(string), typeof(FooBox));
public FooBox()
{
InitializeComponent();
}
public string FooText
{
get { return textBlock.Text; }
set { textBlock.Text = value; }
}
}
<UserControl x:Class="Namespace.FooBox"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Height="300" Width="300">
<Grid>
<TextBlock x:Name="textBlock" />
</Grid>
</UserControl>
On the form it's declared as:
<local:FooBox FooText="{Binding Name}" />
The form's DataContext is set to an object that has a Name property. But this is not working for me. What am I missing?
The "get" and "set" parts of a property declaration in a DependencyProperty aren't actually called by the databinding system of WPF - they're there essentially to satisfy the compiler only.
Instead, change your property declaration to look like this:
public string FooText
{
get { return (string)GetValue(FooTextProperty); }
set { SetValue(FooTextProperty, value); }
}
... and your XAML to:
<UserControl ...
x:Name="me">
<Grid>
<TextBlock Text="{Binding FooText,ElementName=me}" />
</Grid>
</UserControl>
Now your TextBox.Text simply binds directly to the "FooText" property, so you can in turn bind the FooText property to "Name" just like you're currently doing.
Another way is to bind TextBlock.Text to a RelativeSource binding that finds the FooText property on the first ancestor of type "FooBox", but I've found that this is more complex than just giving the control an internal x:Name and using element binding.
Turns out the real problem is I was expecting the WPF framework to set my public property whereupon my code would respond to the changes and render according to the new value. Not so. What WPF does is call SetValue() directly and completely circumvents the public property. What I had to do was receive property change notifications using DependencyPropertyDescriptor.AddValueChanged and respond to that. It looks something like (inside the ctor):
var dpd = DependencyPropertyDescriptor
.FromProperty(MyDependencyProperty, typeof(MyClass));
dpd.AddValueChanged(this, (sender, args) =>
{
// Do my updating.
});