如何将HelpProvider弹出窗口置于模态窗体上？

Question

我将一个HelpProvider添加到一个模态表单中。使用CenterToParent方法显示时，窗体居中。

当我在运行时点击F1键时，帮助字符串弹出窗口显示在屏幕的左下角，只显示帮助字符串的第一部分 - 其余部分在屏幕边缘被切断。

string helpmsg="This is a demonstration of using the HelpProvider class    to show a help string" +
  "when the user hits the F1 key. I works except the help is shown in a box that is cut off in" +
 "the bottom left corner of the screen such that not all of the help is visible."

this.helpProvider1.SetHelpString(this, helpmsg);

this.helpProvider1.SetShowHelp(this, true);