以 ClipCursor 限制滑鼠只能出沒於指定區域.

// 先放兩個 TButton 元件, 各自的 OnClick 事件:
void __fastcall TForm1::Button1Click(TObject *Sender)
{
  TRect rtButton2 = Button2->BoundsRect;
  // 換算成螢幕座標
  MapWindowPoints(Handle, 0, (LPPOINT)&rtButton2, 2); 
  ClipCursor((LPRECT)&rtButton2); // 限制滑鼠移動區域
}

void __fastcall TForm1::Button2Click(TObject *Sender)
{
  TRect rtScreen = Rect(0, 0, Screen->Width, Screen->Height);
  ClipCursor((LPRECT)&rtScreen);
}

    Source: geocities.com/huanlin_tsai/faq

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