在 WPF DataGrid 中实现自定义复制和粘贴，这在其中没有行时有效

Question

我需要为要在 WPF 应用程序中的网格之间复制的数据（不是文本或 CSV）实现自定义复制 + 剪切 + 粘贴。使用标准 ApplicationCommand 和定义 CommandBinding 效果非常好，但前提是 DataGrid 至少包含 1 行数据并且选中它。当没有行或焦点不在任何行上时，所有命令都将被禁用。

为了解决这个问题，我尝试调用 CommandManager.InvalidateRequerySuggested() 并在 DataGrid 上设置 Focusable=true and/or FocusManager.IsFocusScope=true 但似乎在内部 DataGrid 作为一个整体是 "not interested" 在处理 Copy/Paste 操作时，只有它的行是重新查询命令 CanExecute 状态并相应地调用 Execute。它还会忽略 KeyBindings。

如何使 DataGrid 处理重新查询 ApplicationCommands？

请在下面找到我测试问题的示例：

<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <DataGrid x:Name="TheGrid">
        <DataGrid.Columns>
            <DataGridTextColumn Header="Number" Binding="{Binding}"/>
        </DataGrid.Columns>
        <DataGrid.InputBindings>
            <KeyBinding Key="A" Command="{x:Static ApplicationCommands.New}"/>
        </DataGrid.InputBindings>
        <DataGrid.CommandBindings>
            <CommandBinding Command="{x:Static ApplicationCommands.Paste}" CanExecute="CanPaste" Executed="Paste"/>
            <CommandBinding Command="{x:Static ApplicationCommands.Copy}" CanExecute="CanCopy" Executed="Copy"/>
            <CommandBinding Command="{x:Static ApplicationCommands.New}" CanExecute="CanAddNew" Executed="AddNew"/>
        </DataGrid.CommandBindings>
        <DataGrid.ContextMenu>
            <ContextMenu>
                <MenuItem Command="{x:Static ApplicationCommands.Copy}" Header="Copy"/>
                <MenuItem Command="{x:Static ApplicationCommands.Paste}" Header="Paste"/>
                <MenuItem Command="{x:Static ApplicationCommands.New}" Header="New row"/>
            </ContextMenu>
        </DataGrid.ContextMenu>
    </DataGrid>
</Window>

后面的代码：

using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Windows;
using System.Windows.Input;

namespace WpfApplication1
{
    public partial class MainWindow
    {
        public MainWindow()
        {
            InitializeComponent();
            TheGrid.ItemsSource = numbers;
            // Following line enables commands when row is selected
            numbers.Add(0);
        }

        private void Copy(object sender, ExecutedRoutedEventArgs e)
        {
            Clipboard.SetData(DataFormats.Text, string.Join(",", numbers));
        }

        private void CanCopy(object sender, CanExecuteRoutedEventArgs e)
        {
            e.CanExecute = numbers.Count > 0;
        }

        private void CanPaste(object sender, CanExecuteRoutedEventArgs e)
        {
            e.CanExecute = numbers.Count > 0;
            e.Handled = true;
        }

        private void Paste(object sender, ExecutedRoutedEventArgs e)
        {
            Close();
        }

        private void CanAddNew(object sender, CanExecuteRoutedEventArgs e)
        {
            e.CanExecute = true;
            e.Handled = true;
        }

        private void AddNew(object sender, ExecutedRoutedEventArgs e)
        {
            numbers.Add(numbers.Count);
        }

        private readonly ICollection<int> numbers = new ObservableCollection<int>();
    }
}

编辑

Ayyappan Subramanian 的纯代码解决方案是最接近将在其中使用的应用程序的解决方案。最终，由于我已经继承了网格，因为它具有自定义的复制+粘贴格式，所以我添加了一些代码来确保在 3 种情况下，焦点位于网格内：

显示上下文菜单
当子视觉对象没有焦点时，用户在网格（空白）区域中单击
（我们的应用程序特定案例）用户单击网格导航 TreeView，然后将焦点带到网格，因此快捷方式将立即起作用。

相关代码：

public class MyDataGrid: DataGrid
{
        protected override void OnContextMenuOpening(ContextMenuEventArgs e)
        {
            base.OnContextMenuOpening(e);
            Focus();
        }

        protected override void OnMouseUp(MouseButtonEventArgs e)
        {
            base.OnMouseUp(e);
            if(e.ChangedButton == MouseButton.Left && !IsKeyboardFocusWithin)
            {
                Focus();
            }
        }
}

Answer 1

当上下文菜单打开时，您可以将焦点设置到网格，这将启用所有菜单项。这里给出了很好的解释 http://www.wpftutorial.net/RoutedCommandsInContextMenu.html

也可以参考 SO post WPF datagrid pasting

来实现粘贴

WPF:

<DataGrid x:Name="TheGrid" CanUserAddRows="True" 
          ContextMenuOpening="TheGrid_ContextMenuOpening">
    <DataGrid.Columns>
        <DataGridTextColumn Header="Number" Binding="{Binding}"/>
    </DataGrid.Columns>
    <DataGrid.InputBindings>
        <KeyBinding Key="A" Command="{x:Static ApplicationCommands.New}"/>
    </DataGrid.InputBindings>
    <DataGrid.CommandBindings>                
        <CommandBinding Command="{x:Static ApplicationCommands.Paste}" 
                        CanExecute="CanPaste" Executed="Paste"/>
        <CommandBinding Command="{x:Static ApplicationCommands.Copy}" 
                        CanExecute="CanCopy" Executed="Copy"/>
        <CommandBinding Command="{x:Static ApplicationCommands.New}" 
                        CanExecute="CanAddNew" Executed="AddNew"/>
    </DataGrid.CommandBindings>
    <DataGrid.ContextMenu>
        <ContextMenu>                   
            <MenuItem Command="{x:Static ApplicationCommands.Copy}" Header="Copy"/>
            <MenuItem Command="{x:Static ApplicationCommands.Paste}" Header="Paste"/>
            <MenuItem Command="{x:Static ApplicationCommands.New}" Header="New row"/>
        </ContextMenu>
    </DataGrid.ContextMenu>
</DataGrid>

C#代码：

public partial class Window1 : Window
{
    public Window1()
    {
        InitializeComponent(); 
        TheGrid.ItemsSource = numbers;
    }

    private void Copy(object sender, ExecutedRoutedEventArgs e)
    {
        Clipboard.SetData(DataFormats.Text, string.Join(",", numbers));
    }

    private void CanCopy(object sender, CanExecuteRoutedEventArgs e)
    {
        e.CanExecute = true;
    }

    private void CanPaste(object sender, CanExecuteRoutedEventArgs e)
    {
        e.CanExecute = true;
        e.Handled = true;
    }

    private void Paste(object sender, ExecutedRoutedEventArgs e)
    {
        Close();
    }

    private void CanAddNew(object sender, CanExecuteRoutedEventArgs e)
    {
        e.CanExecute = true;
        e.Handled = true;
    }

    private void AddNew(object sender, ExecutedRoutedEventArgs e)
    {
        numbers.Add(numbers.Count);
    }

    private readonly ICollection<int> numbers = new ObservableCollection<int>();

    private void TheGrid_ContextMenuOpening(object sender, ContextMenuEventArgs e)
    {
        TheGrid.Focus();
    }

}

Answer 2

这是我的 VB.NET 版本。它获取一个值，然后将其填充到数据网格中的所有选定单元格中。

Private Sub gridpaste(ByVal pasteValue As String)

    Dim rowInd As Integer = Nothing
    Dim colind As Integer = Nothing
    Dim add As Integer = 1

    For Each c As DataGridCellInfo In LineListDataGrid.SelectedCells

        colind = c.Column.DisplayIndex

        rowInd = GetRowIndex(LineListDataGrid, c)

        Try
            LLDB.LineList.Rows(rowInd)(colind) = pasteValue
        Catch err As Exception
            MessageBox.Show(err.Message)
        End Try
    Next

End Sub

   Public Shared Function GetRowIndex(dataGrid As DataGrid, dataGridCellInfo As DataGridCellInfo) As Integer
    Dim dgrow As DataGridRow = DirectCast(dataGrid.ItemContainerGenerator.ContainerFromItem(dataGridCellInfo.Item), DataGridRow)
    If dgrow IsNot Nothing Then
        Return dgrow.GetIndex()
    Else
        Return -1
    End If

End Function

在 WPF DataGrid 中实现自定义复制和粘贴，这在其中没有行时有效

Implement custom Copy and Paste in WPF DataGrid which works when there are no rows in it

c#

wpf

routed-commands

commandbinding

wpfdatagrid