有条件地显示行详细信息

Question

如果该行没有详细信息怎么办？我使用WPFDataGrid来显示带有行详细信息模板的数据。如果用户没有地址详细信息，我不需要行详细信息。我只需要那些有地址详细信息的用户的行详细信息。

<DataGrid  Name="dgSimple" VerticalAlignment="Center" VerticalContentAlignment="Center" AutoGenerateColumns="False">
    <DataGrid.Columns>
        <DataGridTextColumn Header="Id" Binding="{Binding Id}" IsReadOnly="True" MinWidth="60" Width="*"/>
        <DataGridTextColumn Header="First Name" Binding="{Binding FirrstName}" IsReadOnly="True" MinWidth="60" Width="*"/>
        <DataGridTextColumn Header="Last Name" Binding="{Binding LastName}" IsReadOnly="True" MinWidth="60" Width="*"/>
        <DataGridTextColumn Header="Name" Binding="{Binding Name}" IsReadOnly="True" MinWidth="60" Width="*"/>
        <DataGridTextColumn Header="Birthday" Binding="{Binding Birthday}" IsReadOnly="True" MinWidth="60" Width="*"/>
    </DataGrid.Columns>
    <DataGrid.RowDetailsTemplate>
        <DataTemplate>
            <Border BorderThickness="0" Background="BlanchedAlmond" Padding="10">
                <StackPanel Orientation="Vertical">
                    <StackPanel Orientation="Horizontal">
                        <TextBlock FontSize="12" Text="Address: " VerticalAlignment="Center" />
                        <TextBlock FontSize="16" Foreground="MidnightBlue" Text="{Binding Address}" VerticalAlignment="Center" />
                    </StackPanel>
                </StackPanel>
            </Border>
        </DataTemplate>
    </DataGrid.RowDetailsTemplate>
</DataGrid>

public GridEX_5()
{
    InitializeComponent();
    List<User> users = new List<User>();
    users.Add(new User() { Address = "ABC", Id = 1, FirrstName = "John Doe", LastName = "John Doe", Name = "John Doe", Birthday = new DateTime(1971, 7, 23) });
    users.Add(new User() { Address = "ABC", Id = 2, FirrstName = "John Doe", LastName = "John Doe", Name = "Jane Doe", Birthday = new DateTime(1974, 1, 17) });
    users.Add(new User() { Address = "ABC", Id = 3, FirrstName = "John Doe", LastName = "John Doe", Name = "Sammy Doe", Birthday = new DateTime(1991, 9, 2) });
    users.Add(new User() { Address = "ABC", Id = 1, FirrstName = "John Doe", LastName = "John Doe", Name = "John Doe", Birthday = new DateTime(1971, 7, 23) });
    users.Add(new User() { Address = "ABC", Id = 2, FirrstName = "John Doe", LastName = "John Doe", Name = "Jane Doe", Birthday = new DateTime(1974, 1, 17) });
    users.Add(new User() { Address = "ABC", Id = 3, FirrstName = "John Doe", LastName = "John Doe", Name = "Sammy Doe", Birthday = new DateTime(1991, 9, 2) });
    users.Add(new User() { Address = "ABC", Id = 1, FirrstName = "John Doe", LastName = "John Doe", Name = "John Doe", Birthday = new DateTime(1971, 7, 23) });
    users.Add(new User() { Address = "ABC", Id = 2, FirrstName = "John Doe", LastName = "John Doe", Name = "Jane Doe", Birthday = new DateTime(1974, 1, 17) });
    users.Add(new User() { Address = "ABC", Id = 3, FirrstName = "John Doe", LastName = "John Doe", Name = "Sammy Doe", Birthday = new DateTime(1991, 9, 2) });
    users.Add(new User() { Address = "ABC", Id = 1, FirrstName = "John Doe", LastName = "John Doe", Name = "John Doe", Birthday = new DateTime(1971, 7, 23) });
    users.Add(new User() { Address = "ABC", Id = 2, FirrstName = "John Doe", LastName = "John Doe", Name = "Jane Doe", Birthday = new DateTime(1974, 1, 17) });
    users.Add(new User() { Address = "ABC", Id = 3, FirrstName = "John Doe", LastName = "John Doe", Name = "Sammy Doe", Birthday = new DateTime(1991, 9, 2) });
    users.Add(new User() { Address = "ABC", Id = 1, FirrstName = "John Doe", LastName = "John Doe", Name = "John Doe", Birthday = new DateTime(1971, 7, 23) });
    users.Add(new User() { Address = "ABC", Id = 2, FirrstName = "John Doe", LastName = "John Doe", Name = "Jane Doe", Birthday = new DateTime(1974, 1, 17) });
    users.Add(new User() { Id = 3, FirrstName = "John Doe", LastName = "John Doe", Name = "Sammy Doe", Birthday = new DateTime(1991, 9, 2) });
    users.Add(new User() { Id = 1, FirrstName = "John Doe", LastName = "John Doe", Name = "John Doe", Birthday = new DateTime(1971, 7, 23) });
    users.Add(new User() { Id = 2, FirrstName = "John Doe", LastName = "John Doe", Name = "Jane Doe", Birthday = new DateTime(1974, 1, 17) });
    users.Add(new User() { Id = 3, FirrstName = "John Doe", LastName = "John Doe", Name = "Sammy Doe", Birthday = new DateTime(1991, 9, 2) });

    dgSimple.ItemsSource = users;
}

Answer 1

您可以使用DataTrigger创建ItemContainerStyle，该触发器检查Address属性是否为null，并将行的DetailsVisibility属性设置为collapped，以隐藏该行。

<DataGrid  Name="dgSimple" VerticalAlignment="Center" VerticalContentAlignment="Center" AutoGenerateColumns="False">
   <DataGrid.ItemContainerStyle>
      <Style TargetType="{x:Type DataGridRow}">
         <Style.Triggers>
            <DataTrigger Binding="{Binding Address}" Value="{x:Null}">
               <Setter Property="DetailsVisibility" Value="Collapsed"/>
            </DataTrigger>
         </Style.Triggers>
      </Style>
   </DataGrid.ItemContainerStyle>
   <!-- ...other markup. -->
</DataGrid>

如果行详细信息模板增长，并且您只想隐藏特定部分，您也可以尝试使用DataTem板中的触发器隐藏它们。但是，如果像本例中那样隐藏所有元素，容器的边框仍然可见（选择时的粗线）。

<DataTemplate>
   <Border x:Name="RowDetailsContainer"  BorderThickness="0" Background="BlanchedAlmond" Padding="10">
      <StackPanel Orientation="Vertical">
         <StackPanel Orientation="Horizontal">
            <TextBlock FontSize="12" Text="Address: " VerticalAlignment="Center" />
            <TextBlock FontSize="16" Foreground="MidnightBlue" Text="{Binding Address}" VerticalAlignment="Center" />
         </StackPanel>
      </StackPanel>
   </Border>
   <DataTemplate.Triggers>
      <DataTrigger Binding="{Binding Address}" Value="{x:Null}">
         <Setter TargetName="RowDetailsContainer" Property="Visibility" Value="Collapsed"/>
      </DataTrigger>
   </DataTemplate.Triggers>
</DataTemplate>