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[英]Binding to dependencyproperty in user control and calling CanExecute on nested property change
[英]Binding DependencyProperty in nested user controls
我有這個問題:我做了2個用戶控件:NestedControl1和NestedControl2。 NestedControl2包含NestedControl1,而NestedControl1僅包含TextBlock。 我已將每個NestedControl * DataContext設置為Self,並為每個對象創建了一個依賴項屬性。 NestedControl1.MyText1和NestedControl2.MyText2。 然后,將NestedControl2.MyText1綁定到MyText2,將TextBlock.Text綁定到MyText1。
如果我在窗口上使用NestedControl2並將MyText2設置為任何值,它將無法正常工作。 但是,如果我直接在Window上使用NestedControl1,它確實可以工作。 關鍵是我想使MyText2的值到達NestedControl1內部的TextBlock.Text屬性。
代碼如下。怎么了? 任何想法?? 預先感謝tou的解答
NestedControl2代碼:
public partial class NestedControl2 : UserControl
{
public NestedControl2()
{
InitializeComponent();
}
public static readonly DependencyProperty MyText2Property = DependencyProperty.Register(
"MyText2", typeof(string), typeof(NestedControl2), new PropertyMetadata(default(string)));
public string MyText2
{
get { return (string)GetValue(MyText2Property); }
set { SetValue(MyText2Property, value); }
}
}
NestedControl2 xaml:
<UserControl x:Class="TestNestedPropertiesWpf.NestedControl2"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:testNestedPropertiesWpf="clr-namespace:TestNestedPropertiesWpf"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300"
DataContext="{Binding RelativeSource={RelativeSource Self}}"
HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
<Grid>
<testNestedPropertiesWpf:NestedControl1 MyText1="{Binding MyText2}" />
</Grid>
NestedControl1代碼:
public partial class NestedControl1 : UserControl
{
public NestedControl1()
{
InitializeComponent();
}
public static readonly DependencyProperty MyText1Property = DependencyProperty.Register(
"MyText1", typeof(string), typeof(NestedControl1), new PropertyMetadata(default(string)));
public string MyText1
{
get { return (string)GetValue(MyText1Property); }
set { SetValue(MyText1Property, value); }
}
}
NestedControl1 xaml:
<UserControl x:Class="TestNestedPropertiesWpf.NestedControl1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:testNestedPropertiesWpf="clr-namespace:TestNestedPropertiesWpf"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300" DataContext="{Binding RelativeSource={RelativeSource Self}}">
<Grid>
<TextBlock Text="{Binding MyText1}"
x:Name="textBlock" Foreground="Red"
Width="300" Height="100" Background="Black"></TextBlock>
</Grid>
最后是MainWindow.xaml:
<Window x:Class="TestNestedPropertiesWpf.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:testNestedPropertiesWpf="clr-namespace:TestNestedPropertiesWpf"
Title="MainWindow" Height="350" Width="525" DataContext="{Binding RelativeSource={RelativeSource Self}}">
<StackPanel>
<testNestedPropertiesWpf:NestedControl1 MyText1="WORKING"/>
<testNestedPropertiesWpf:NestedControl2 MyText2="NOT WORKING"/>
</StackPanel>
這行不通:
testNestedPropertiesWpf:NestedControl1 MyText1="{Binding MyText2}"
添加clr屬性以將值從一個DP傳遞到另一個DP:
我找到了解決方案。 NestedControl2擁有自己的DataContext,並且使用NestedControl1,擁有DataContext到自己,因此這兩個DataContext是不同的。 為了解決該問題,我修改了MyText1中聲明的綁定,如下所示:
<testNestedPropertiesWpf:NestedControl1 MyText1="{Binding RelativeSource={RelativeSource AncestorType={x:Type testNestedPropertiesWpf:NestedControl2}}, Path=MyText2}" />
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