// 手势事件 touchstart //当手指接触屏幕时触发 touchmove //当已经接触屏幕的手指开始移动后触发 touchend //当手指离开屏幕时触发 touchcancel // 触摸事件 gesturestart //当两个手指接触屏幕时触发 gesturechange //当两个手指接触屏幕后开始移动时触发 gestureend // 屏幕旋转事件 onorientationchange // 检测触摸屏幕的手指何时改变方向 orientationchange // touch事件支持的相关属性 touches targetTouches changedTouches clientX // X coordinate of touch relative to the viewport (excludes scroll offset) clientY // Y coordinate of touch relative to the viewport (excludes scroll offset) screenX // Relative to the screen screenY // Relative to the screen pageX // Relative to the full page (includes scrolling) pageY // Relative to the full page (includes scrolling) target // Node the touch event originated from identifier // An identifying number, unique to each touch event