一直撞到墙上,发现是时候发一个问题了。我有以下用户控件
XAML
<UserControl x:Class="WorkDayManager3.WPF.UserControls.TimeControl"
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"
mc:Ignorable="d"
d:DesignHeight="46" d:DesignWidth="133" Background="Transparent"
DataContext="{Binding RelativeSource={RelativeSource self}}">
<Grid Height="44" Width="132" Background="Transparent">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="29" />
</Grid.ColumnDefinitions>
<TextBox Name="label" Text="{Binding Text}" Grid.ColumnSpan="5"></TextBox>
</Grid>
C#
public partial class TimeControl : UserControl
{
public string Text
{
get { return (string)GetValue(TextProperty); }
set { SetValue(TextProperty, value); }
}
// Using a DependencyProperty as the backing store for Text. This enables animation, styling, binding, etc...
public static readonly DependencyProperty TextProperty =
DependencyProperty.Register("Text", typeof(string), typeof(TimeControl), new UIPropertyMetadata("N/A"));
public TimeControl()
{
InitializeComponent();
}
在我使用控件的窗口中,它在网格中使用,其datacontext设置为StaticResource
<Grid Grid.Row="1" HorizontalAlignment="Center" DataContext="{StaticResource shiftViewSource}" Name="grid1" Margin="48,10,38,0">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<TextBox Grid.Column="0" Grid.Row="1" Height="23" TabIndex="2" HorizontalAlignment="Left" Margin="10,5,0,5" Name="shiftNameTextBox" Text="{Binding Path=ShiftName, Mode=TwoWay, ValidatesOnExceptions=true, NotifyOnValidationError=true}" VerticalAlignment="Center" Width="120" />
<my2:TimeControl Grid.Column="0" Grid.Row="2" Height="23" TabIndex="2" HorizontalAlignment="Left" Margin="10,5,0,5" Name="shiftNameTextBox" Text="{Binding Path=ShiftName, Mode=TwoWay, ValidatesOnExceptions=true, NotifyOnValidationError=true}" VerticalAlignment="Center" Width="120" />
<my2:TimeControl Grid.Column="0" Grid.Row="3" Text="THIS WORKS OK"/>
</Grid>
现在绑定到Path ShiftName的TextBox正常工作并显示文本。当我使用我的控件时,它不会显示预期的文本。但是在第二个例子中,我只是将Text依赖属性设置为“THIS WORKS OK”,文本按预期显示。为什么绑定适用于TextBox但不适用于我的控件。我做错了什么?
答案 0 :(得分:6)
您已将DataContext
上的UserControl
设置为自己。因此,TimeControl
Text
属性的绑定正在尝试在ShiftName
上找到名为TimeControl
的属性,而不是在静态资源上。如果您查看visual studio的输出窗口,您应该会看到一条错误消息。
无论如何在DataContext
设置UserControl
绝不是一个好主意,因为任何人都可以覆盖它。你可以这样做:
<UserControl x:Name="root" ...>
<Grid DataContext="{Binding ElementName=root}"
...
答案 1 :(得分:0)
另一种方法可能是使用相对绑定:
<Grid DataContext="{Binding RelativeSource={RelativeSource AncestorType={x:Type UserControl}}}" >
...