背景

組件手勢檢測，單擊、雙擊、長按、松開、移動、橫向拖動、豎向拖動等事件

屬性	作用
onTap	單擊
onDoubleTap	雙擊
onLongPress	長按
onPanUpdate	拖動實時更新
onHorizontalDragDown	橫向點擊
onVerticalDragDown	豎向點擊

 GestureDetector(onTap: () => setState(() => _info = 'onTap'),onDoubleTap: () => setState(() => _info = 'onDoubleTap'),onLongPress: () => setState(() => _info = 'onLongPress'),onHorizontalDragDown: (detail) => setState(() {detail.globalPosition;detail.localPosition;}),child: Container(alignment: Alignment.center,width: 300,height: 300 * 0.4,color: Colors.grey.withAlpha(33),child: Text(_info,style: const TextStyle(fontSize: 18, color: Colors.blue),),),)