WPF 的嵌套数据网格 FindResource 问题

Question

我对 WPF 中的嵌套数据网格有要求。 父网格显示消费者的订单信息。当用户单击订单信息中的详细信息时，需要在订单信息的父行内的子数据网格（意味着嵌套网格）中显示订购的商品详细信息。 为此，我使用<DataGrid.RowDetailsTemplate> 绑定子数据网格。 我的 XAML 代码如下。

<Popup Name="popup1" IsOpen="False" Placement="Mouse" Height="500" Width="700">                       
    <Border BorderBrush="Black" BorderThickness="1" Background="White">
        <StackPanel Orientation="Horizontal">                   
            <Grid>
               <Grid.RowDefinitions>
                    <RowDefinition Height="Auto"/>
                    <RowDefinition Height="Auto" />

                    <RowDefinition Height="Auto" />
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition />
                    <ColumnDefinition />
                </Grid.ColumnDefinitions>                        
                <DataGrid Grid.Row="0" Grid.Column="0" SelectedValuePath="orderid" 
                          AutoGenerateColumns="False" Height="350"  
                          HorizontalAlignment="Left" Margin="114,128,0,0" x:Name="gridOrder" VerticalAlignment="Top" Width="500">
                    <DataGrid.Columns>                                
                        <DataGridTemplateColumn Header="Order Status">
                            <DataGridTemplateColumn.CellTemplate>
                                <DataTemplate>
                                    <Button Content="{Binding OrderStatus}" Click="EditButton_Click" />                                            
                                </DataTemplate>                                        
                            </DataGridTemplateColumn.CellTemplate>                                    
                        </DataGridTemplateColumn>                                
                        <DataGridTextColumn Header="Full Name" Binding="{Binding fullname}" />
                        <DataGridTextColumn Header="Order ID" Binding="{Binding orderid}" />                                
                        <DataGridTextColumn Header="Mobile" Binding="{Binding mobile}" />
                        <DataGridTextColumn Header="No. of Items" Binding="{Binding countofItems}" />                                   
                        <DataGridTextColumn Header="Total Price" Binding="{Binding Total_Price}" />
                        <DataGridTextColumn Header="Order Status" Binding="{Binding OrderStatus}" />
                    </DataGrid.Columns> 
                    <DataGrid.RowDetailsTemplate>
                        <DataTemplate>
                            <DataGrid x:Name="gridOrderDetails"  AutoGenerateColumns="False" 
                                      Height="200" HorizontalAlignment="Left" Margin="121,132,0,0" VerticalAlignment="Top" Width="200">
                                <DataGrid.Columns>
                                    <DataGridTextColumn Header="Item ID" Binding="{Binding itemid}" />
                                    <DataGridTextColumn Header="Item Name" Binding="{Binding ItemName}" />
                                    <DataGridTextColumn Header="Item No." Binding="{Binding ItemNo}" />
                                    <DataGridTextColumn Header="Quantity" Binding="{Binding quantity}" />
                                    <DataGridTextColumn Header="Comments" Binding="{Binding comments}" />
                                    <DataGridTextColumn Header="Item Price" Binding="{Binding ItemPrice}" />
                                    <DataGridTextColumn Header="Quantity" Binding="{Binding quantity}" />
                                </DataGrid.Columns>
                            </DataGrid>

                        </DataTemplate>
                    </DataGrid.RowDetailsTemplate>
                </DataGrid>                       

                <Button Content="Close" Grid.Row="1" Grid.Column="1" Click="PopUp_OK_Click"/>
            </Grid>

        </StackPanel>
    </Border>
</Popup>

我的C#代码如下：

private void EditButton_Click(object sender, RoutedEventArgs e)
{
    try
    {
        DBDataContext dbContext = new DBDataContext();
        SP_Get_OrderItemResult orderRow = gridOrder.SelectedItem as SP_Get_OrderItemResult;                
        DataGrid grid = gridOrder.FindResource("gridOrderDetails") as DataGrid;                             
        grid.ItemsSource = dbContext.SP_Get_ItemList(orderRow.orderid); 
    }
    catch (Exception Ex)
    {
        MessageBox.Show(Ex.Message);
        return;
    }
}

我无法将 gridOrder 的 orderid 传入 FindResource(:gridOrderDetails").

DataGrid grid = gridOrder.FindResource("gridOrderDetails") as DataGrid;

在上一行出现错误，因为 'gridOrderDetails' 资源不是 找到了。

Answer 1

那是因为gridOrderDetails 不是资源。资源在资源字典中是这样定义的，gridOrderDetails 只是模板中的一个控件。

尝试改用the function that answered this question：

private void EditButton_Click(object sender, RoutedEventArgs e)
{
    try
    {
        DBDataContext dbContext = new DBDataContext();
        SP_Get_OrderItemResult orderRow = gridOrder.SelectedItem as SP_Get_OrderItemResult;                
        DataGrid grid = FindChild<DataGrid>(gridOrder, "gridOrderDetails");                      
        grid.ItemsSource = dbContext.SP_Get_ItemList(orderRow.orderid); 
    }
    catch (Exception Ex)
    {
        MessageBox.Show(Ex.Message);
        return;
    }
}

/// <summary>
/// Finds a Child of a given item in the visual tree. 
/// </summary>
/// <param name="parent">A direct parent of the queried item.</param>
/// <typeparam name="T">The type of the queried item.</typeparam>
/// <param name="childName">x:Name or Name of child. </param>
/// <returns>The first parent item that matches the submitted type parameter. 
/// If not matching item can be found, 
/// a null parent is being returned.</returns>
public static T FindChild<T>(DependencyObject parent, string childName)
   where T : DependencyObject
{    
  // Confirm parent and childName are valid. 
  if (parent == null) return null;

  T foundChild = null;

  int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
  for (int i = 0; i < childrenCount; i++)
  {
    var child = VisualTreeHelper.GetChild(parent, i);
    // If the child is not of the request child type child
    T childType = child as T;
    if (childType == null)
    {
      // recursively drill down the tree
      foundChild = FindChild<T>(child, childName);

      // If the child is found, break so we do not overwrite the found child. 
      if (foundChild != null) break;
    }
    else if (!string.IsNullOrEmpty(childName))
    {
      var frameworkElement = child as FrameworkElement;
      // If the child's name is set for search
      if (frameworkElement != null && frameworkElement.Name == childName)
      {
        // if the child's name is of the request name
        foundChild = (T)child;
        break;
      }
    }
    else
    {
      // child element found.
      foundChild = (T)child;
      break;
    }
  }

  return foundChild;
}