使用react native
PanResponder,当屏幕触摸坐标超出某个值范围时,如何阻止移动？
例如,如何阻止用户将组件移动到屏幕上某个y位置以下？
PanResponder使用Gesture Responder System.
我正在仔细阅读文档,但我找不到答案.
任何帮助是极大的赞赏.
查看您提供的PanResponder文档页面(
https://facebook.github.io/react-native/docs/panresponder.html),我认为您可以修改示例以满足您的需求.
负责响应手势采取操作的函数是PanResponder的一个属性,名为onPanResponderMove,在示例代码中看起来像这样：
_handlePanResponderMove: function(e: Object,gestureState: Object) {
this._circleStyles.style.left = this._prevIoUsLeft + gestureState.dx;
this._circleStyles.style.top = this._prevIoUsTop + gestureState.dy;
this._updateNativeStyles();
},
gestureState对象的位置如下所示：
stateID - ID of the gestureState- persisted as long as there at least one touch on screen moveX - the latest screen coordinates of the recently-moved touch moveY - the latest screen coordinates of the recently-moved touch x0 - the screen coordinates of the responder grant y0 - the screen coordinates of the responder grant dx - accumulated distance of the gesture since the touch started dy - accumulated distance of the gesture since the touch started vx - current velocity of the gesture vy - current velocity of the gesture numberActiveTouches - Number of touches currently on screen
您可以在_handlePanResponderMove中添加条件检查以确定gestureState.y0是否低于某个阈值,并且只应用更改
