我是 WPF 的新手,所以我在我的自定义控件单击按钮上被困住了一些绑定。
我有具有水印和 selctedItems 属性的文本框。控制如果选定项 != null 在控件中将它们显示如下:
链接到图片[http://s29.postimg.org/p25qgqzwn/image.jpg][1]
现在我需要连接 X 按钮以从选定的项目源中删除该项目。我正在尝试在 OnApplyTemplate 方法中执行此操作,但我不知道如何访问 itemscontrol 中的该按钮以附加鼠标单击事件。
我的 Xaml
<Style TargetType="{x:Type local:TextBoxPicker}">
<Setter Property="Background" Value="{DynamicResource {x:Static SystemColors.WindowBrushKey}}"/>
<Setter Property="BorderBrush" Value="{StaticResource TextBox.Static.Border}"/>
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="KeyboardNavigation.TabNavigation" Value="None"/>
<Setter Property="HorizontalContentAlignment" Value="Left"/>
<Setter Property="FocusVisualStyle" Value="{x:Null}"/>
<Setter Property="AllowDrop" Value="true"/>
<Setter Property="ScrollViewer.PanningMode" Value="VerticalFirst"/>
<Setter Property="Stylus.IsFlicksEnabled" Value="False"/>
<Setter Property="WatermarkTemplate" Value="{StaticResource DefaultWatermarkTemplate}"/>
<Setter Property="SelectedItemsTemplate" Value="{StaticResource DefaultSelectedItemsTemplate}" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:TextBoxPicker}">
<Grid>
<Border x:Name="border" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" SnapsToDevicePixels="True">
<ScrollViewer x:Name="PART_ContentHost" Focusable="false" HorizontalScrollBarVisibility="Hidden" VerticalScrollBarVisibility="Hidden"/>
</Border>
<Border BorderBrush="Red" BorderThickness="1">
<ContentControl x:Name="PART_WatermarkHost"
Content="{TemplateBinding Watermark}"
ContentTemplate="{TemplateBinding WatermarkTemplate}"
VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
IsHitTestVisible="False"
Margin="{TemplateBinding Padding}"
Visibility="Collapsed" />
</Border>
<Border BorderBrush="Green" BorderThickness="1">
<ItemsControl x:Name="PART_SelectedItemsHost"
ItemsSource="{TemplateBinding SelectedItems}"
ItemTemplate="{TemplateBinding SelectedItemsTemplate}"
VerticalAlignment="Stretch"
HorizontalAlignment="Stretch"
Margin="{TemplateBinding Padding}"
Visibility="Visible">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<WrapPanel>
</WrapPanel>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
</ItemsControl>
</Border>
</Grid>
....
</ControlTemplate>
</Setter.Value>
</Setter>
我的项目模板看起来像这样
XAML:
<DataTemplate x:Key="DefaultSelectedItemsTemplate" >
<Border x:Name="selectedItemBorder" BorderBrush="Gray" BorderThickness="1" CornerRadius="5" Background="{DynamicResource {x:Static SystemColors.ControlBrushKey}}" Margin="5,1,1,1">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="15"/>
</Grid.ColumnDefinitions>
<!--<TextBlock Grid.Column="0" Text="{Binding RelativeSource={RelativeSource Self}, Path=Ime}" Margin="5,0,3,0"></TextBlock>-->
<TextBlock Grid.Column="0" Text="{Binding}" Margin="5,0,3,0"></TextBlock>
<Button x:Name="PART_selectedItemButton" BorderThickness="0" Grid.Column="1" >X</Button>
</Grid>
</Border>
</DataTemplate>
.cs代码
public override void OnApplyTemplate()
{
base.OnApplyTemplate();
ItemsControl selectedItem = GetTemplateChild("PART_SelectedItemsHost") as ItemsControl;
if (selectedItem != null)
{
selectedItem.MouseLeftButtonDown += new MouseButtonEventHandler(selectedItemBorder_MouseLeftButtonDown);
// blind click on X buttons in ItemsControl
}
}
那么如何在代码隐藏中的项目上绑定单击"X"按钮呢?
首先是带有 ObservableCollection 的视图模型和将执行 X 的命令:
private ObservableCollection<string> items = new ObservableCollection<string>() { "One", "Two", "Three" };
public ObservableCollection<String> Items
{
get
{
return items;
}
set
{
items = value;
NotifyPropertyChanged();
}
}
public Command<String> DeleteItem
{
get
{
return new Command<string>((item) =>
{
if (items.Contains(item))
{
items.Remove(item);
}
NotifyPropertyChanged("Items");
});
}
}
现在是 XAML:
资源,它绑定到"父"数据上下文,这是一种了解绑定去向的简单方法:
<Page.Resources>
<DataTemplate x:Key="DefaultSelectedItemsTemplate" >
<Border x:Name="selectedItemBorder" BorderBrush="Gray" BorderThickness="1" CornerRadius="5" Margin="5,1,1,1">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="15"/>
</Grid.ColumnDefinitions>
<!--<TextBlock Grid.Column="0" Text="{Binding RelativeSource={RelativeSource Self}, Path=Ime}" Margin="5,0,3,0"></TextBlock>-->
<TextBlock Grid.Column="0" Text="{Binding}" Margin="5,0,3,0"></TextBlock>
<Button x:Name="PART_selectedItemButton" BorderThickness="0" Grid.Column="1" Command="{Binding DataContext.DeleteItem, ElementName=ItemsControlInstance}" CommandParameter="{Binding}">X</Button>
</Grid>
</Border>
</DataTemplate>
</Page.Resources>
最后是项目控制:
<ItemsControl x:Name="ItemsControlInstance" ItemTemplate="{StaticResource DefaultSelectedItemsTemplate}" ItemsSource="{Binding Items}"/>
最后,我设法让它工作,在 Jaun 的帮助和指导下,它仍然不起作用(我尝试了大约 10 种不同的东西,它在 DataContext 中......它从未绑定过。
所以在我的覆盖上应用模板我添加了这个。数据上下文 = 这个 ...所以我错过了那部分。
我使用 AttachedCommandBehavior (nuget) 作为命令
法典:
public override void OnApplyTemplate()
{
base.OnApplyTemplate();
this.DataContext = this;
ItemsControl itmControl = GetTemplateChild("PART_SelectedItemsHost") as ItemsControl;
if (itmControl != null)
{
itmControl.MouseLeftButtonDown += new MouseButtonEventHandler(itmControl_MouseLeftButtonDown);
// blind click on X buttons in ItemsControl
}
}