wpf使用usercontrol自定义标签

   <UserControl.ContentTemplate>
        <DataTemplate>
            <Grid>
                <Grid.RowDefinitions>
                    <RowDefinition Height="25"/>
                    <RowDefinition Height="*"/>
                </Grid.RowDefinitions>
                <Grid Background="#1979ca" Grid.Row="0">
                    <TextBox Name="title" Text="{Binding Header,ElementName=comstom}" Background="Transparent" HorizontalAlignment="Left" 
                         Foreground="White" VerticalAlignment="Center" BorderThickness="0"/>
                    <Image Source="Resource/a.png" HorizontalAlignment="Right" Margin="6,0" Height="18" MouseLeftButtonDown="Image_MouseLeftButtonDown"/>
                </Grid>
                <ContentPresenter Content="{Binding}" Grid.Row="1" />
            </Grid>
        </DataTemplate>
    </UserControl.ContentTemplate>

public static DependencyProperty HeaderProperty =
    DependencyProperty.Register("Header", typeof(string), typeof(TitleWindow), new PropertyMetadata(""));
public string Header
{
     get { return (string)GetValue(HeaderProperty); }
     set{SetValue(HeaderProperty, value);}
}

<ContentPresenter Content="{Binding}" Grid.Row="1" />