WPF - 将Datagrid Items.Count绑定到自定义控件标签

Question

我是wpf的新手,并尝试将静态定义的DataGrid的Items.Count属性绑定到我的自定义控件的Label.

我目前的实现看起来像这样.但标签仍然是空的:我

定义DataGrid的类:

public class BindingNavigator : Control
{
    private static DataGrid dataGrid;

    static BindingNavigator()
    {
        DefaultStyleKeyProperty.OverrideMetadata(typeof(BindingNavigator), new FrameworkPropertyMetadata(typeof(BindingNavigator)));
    }

    public DataGrid DataGrid
    {
        set { dataGrid = value; }
        get { return dataGrid; }
    }
}

CustomControl的XAML,其中Items.Count将显示在标签中

<Style TargetType="{x:Type local:BindingNavigator}">
   <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type local:BindingNavigator}">
                <Border Background="{TemplateBinding Background}"
                        BorderBrush="{TemplateBinding BorderBrush}"
                        BorderThickness="{TemplateBinding BorderThickness}">
                    <Grid MinWidth="210" MinHeight="50">
                        <Label Width="30" Height="30" Content="{Binding ElementName=DataGrid, Path=Items.Count}" />
                    </Grid>
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

我部署自定义控件的XAML

    <DataGrid Name="dataGrid1" VerticalAlignment="Top" Width="210">
        <DataGrid.Columns>
            <DataGridTextColumn Header="header" />
        </DataGrid.Columns>
    </DataGrid>
    <my:BindingNavigator Name="bindingNavigator1" />
</Grid>

EventHandler背后的代码,我填充网格并设置自定义控件的DataGrid属性

    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
        dataGrid1.Items.Add("1");
        dataGrid1.Items.Add("2");

        bindingNavigator1.DataGrid = dataGrid1;
    }

为什么我不能将Items.Count属性绑定到Label？

Answer 1

您需要做的就是将ElementName的值更改为DataGrid的实际名称(即dataGrid1而不是DataGrid).

    <Label Width="30" Height="30" 
Content="{Binding ElementName=DataGrid, Path=Items.Count}" />

这是一个完整的例子:

  <Grid>
        <Grid.Resources>
            <Style TargetType="{x:Type local:BindingNavigator}">
                <Setter Property="Template">
                    <Setter.Value>
                        <ControlTemplate TargetType="{x:Type local:BindingNavigator}">
                            <Border Background="{TemplateBinding Background}"
                        BorderBrush="{TemplateBinding BorderBrush}"
                        BorderThickness="{TemplateBinding BorderThickness}">
                                <Grid MinWidth="210" MinHeight="50">
                                    <Label Width="30" Height="30" 
Content="{Binding ElementName=dataGrid1, Path=Items.Count}" />
                                </Grid>
                            </Border>
                        </ControlTemplate>
                    </Setter.Value>
                </Setter>
            </Style>

        </Grid.Resources>
        <StackPanel>
            <DataGrid Name="dataGrid1" VerticalAlignment="Top" Width="210">
                <DataGrid.Columns>
                    <DataGridTextColumn Header="header" />
                </DataGrid.Columns>
            </DataGrid>
            <local:BindingNavigator x:Name="bindingNavigator1" />
        </StackPanel>
    </Grid>