Question

我想在类文件方法中从checklistbox（winform控件）中删除已检查的项目，我使用deletegate异步调用。但它显示了这个错误信息： -

跨线程操作无效：控制'checkedListBox1'从其创建的线程以外的线程访问。

我已经尝试过调用，但又遇到了同样的错误。示例代码如下：

private void button1_Click(object sender, EventArgs e)
{
   // Create an instance of the test class.
   Class1 ad = new Class1();
   // Create the delegate.
   AsyncMethodCaller1 caller = new AsyncMethodCaller1(ad.TestMethod1);
   //callback delegate
   IAsyncResult result = caller.BeginInvoke(checkedListBox1,
                             new AsyncCallback(CallbackMethod)," ");
    }

在TestMethod1的类文件代码中： -

private delegate void dlgInvoke(CheckedListBox  c, Int32 str);

private void Invoke(CheckedListBox c, Int32 str)
 {
  if (c.InvokeRequired)
   {
     c.Invoke(new dlgInvoke(Invoke), c, str);
     c.Items.RemoveAt(str);
   }
  else
  {
    c.Text = "";
  }

 }
// The method to be executed asynchronously.

public string TestMethod1(CheckedListBox chklist)
{
 for (int i = 0; i < 10; i++)
   {
     string chkValue = chklist.CheckedItems[i].ToString();
     //do some other database operation based on checked items.
     Int32 index = chklist.FindString(chkValue);
     Invoke(chklist, index);
  }
 return "";
}

Answer 1

您确定没有从这行代码中收到错误吗？

string chkValue = chklist.CheckedItems[i].ToString();

跨线程操作无效：从创建它的线程以外的线程访问

1 个答案: