C# 无法使用contextmenustrip项显示按钮文本

我的表单上有许多按钮是由代码（表单加载事件）生成的，如下所示：

for(int j = 0; j < 30; j++)
{
    Button btn = new Button();
    btn.Text = numb_cust;
    //The text will be different for every button created
    btn.ContextMenuStrip = MyContextMS;
    //Every button will have this contextMenuStrip
}

---

但是，当按钮b尝试显示MessageBox时，我在按钮b上看到NullReferenceException，请帮助我。

发件人永远不会是按钮，因为发件人是执行单击操作的ToolStripMenuItem

尝试检查SourceControl属性：

Control ctrl;

void MyContextMS_Opening(object sender, CancelEventArgs e) {
  ctrl = ((ContextMenuStrip)sender).SourceControl;
}

private void SeeDetailsToolStripMenuItem_Click(object sender, EventArgs e) {
  Button b = ctrl as Button;
  if (b != null) {
    MessageBox.Show(b.Text);
  }
}

---

如果

MyContextMS

处于表单级别，那么您也可以执行以下操作：

Button b=（Button）MyContextMS.SourceControl。
Control ctrl;

void MyContextMS_Opening(object sender, CancelEventArgs e) {
  ctrl = ((ContextMenuStrip)sender).SourceControl;
}

private void SeeDetailsToolStripMenuItem_Click(object sender, EventArgs e) {
  Button b = ctrl as Button;
  if (b != null) {
    MessageBox.Show(b.Text);
  }
}