c# - 使用空格键更改 CheckBox 时，AcceptChanges() 在 DataGridView 中抛出 System.NullReferenceException

Question

在我的 DataGridView 中，我使用 DataView 来过滤 DataTable。 CheckBox 值在过滤器中使用。

当取消选中 CheckBox 时，该行应该消失。为了立即运行它，我在 CurrentCellDirtyStateChanged 事件中使用了 AcceptChanges()。 (否则该行会一直显示，直到选择了另一行)。

This works when I unselect the checkbox with the mouse. Using the space bar a NullReferenceException exception is thrown.

下面是一些示例代码:

(完整工作。只需要带有空白 DataGridView1 的 Form1。使用空格键更改 CheckBox 会引发异常)

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        DataTable table;
        DataView view; 

        public Form1()
        {
            InitializeComponent();

            Init();
        }

        // Building the table and view
        private void Init()
        {
            table = new DataTable();
            table.Columns.Add("check", typeof(bool));

            table.Rows.Add(true);
            table.Rows.Add(true);
            table.Rows.Add(true);

            view = new DataView(table);
            view.RowFilter = "check = true";

            dataGridView1.DataSource = view;
        }

        // CurrentCellDirtyStateChanged Event
        private void dataGridView1_CurrentCellDirtyStateChanged(object sender, EventArgs e)
        {
            if (dataGridView1.IsCurrentCellDirty == true && dataGridView1.CurrentCell is DataGridViewCheckBoxCell)
            {
                dataGridView1.CommitEdit(DataGridViewDataErrorContexts.Commit);

                // AcceptChanges to update the view
                // works with mouse click, throws NullReferenceException when spacebar is used
                table.AcceptChanges();
            }
        }
    }
}

有什么方法可以让它也与空格键一起工作吗？

编辑
.net 运行时的任何地方都会抛出异常，而不是直接由 AcceptChanges() 抛出

System.NullReferenceException: Der Objektverweis wurde nicht auf eine Objektinstanz festgelegt.
     bei System.Windows.Forms.DataGridViewCheckBoxCell.NotifyMASSClient(Point position)
     bei System.Windows.Forms.DataGridViewCheckBoxCell.OnKeyUp(KeyEventArgs e, Int32 rowIndex)
     bei System.Windows.Forms.DataGridView.OnKeyUp(KeyEventArgs e)
     bei System.Windows.Forms.Control.ProcessKeyEventArgs(Message& m)
     bei System.Windows.Forms.DataGridView.ProcessKeyEventArgs(Message& m)
     bei System.Windows.Forms.Control.WmKeyChar(Message& m)
     bei System.Windows.Forms.Control.WndProc(Message& m)
     bei System.Windows.Forms.DataGridView.WndProc(Message& m)
     bei System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
     bei System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
     bei System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
     bei System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
     bei System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
     bei Sample.Program.Main() in C:\Projects\TFS\Sample\Sample\Program.cs:Zeile 21.

Answer 1

以这种方式使用 Invoke 使代码更易于阅读，因为不需要显式委托(delegate)声明。

private void dataGridView1_CurrentCellDirtyStateChanged(object sender, EventArgs e)
{
    if (dataGridView1.IsCurrentCellDirty == true && dataGridView1.CurrentCell is DataGridViewCheckBoxCell)
    {
        // use BeginInvoke with (MethodInvoker) to run the code after the event is finished
        BeginInvoke((MethodInvoker)delegate
        {
            dataGridView1.CommitEdit(DataGridViewDataErrorContexts.Commit);
            table.AcceptChanges();
        });
    }
}

与 tezzos 答案一样工作。