限制panResponder走出手机屏幕

Question

I'm having a problem with panResponder from going outside the phone screen. I get this code from https://reactnative.dev/docs/panresponder#example . Here are some photos.

the box is able to drag/go outside the screen, how to avoid this? I appreciate the help.

Answer 1

You can to make use of Animated.diffClamp or extrapolate

diffClamp logic -

const animtion = new Animated.ValueXY(0);  // you need to update this while dragging
const translateX = Animated.diffClamp(animtion.x, 0, screenWidth - boxWidth);
const translateY = Animated.diffClamp(animtion.y, 0, screenHeight - boxHeight);

return(<View style={[styles.box,{transform:[{translateX},{translateY}]}]} />)

extrapolate logic -

const animtion = new Animated.ValueXY(0);  // you need to update this while dragging
const translateX = animation.x.interpolate({inputRange:[0,screenWidth - boxWidth],outputRange:[0,screenWidth - boxWidth], extrapolate: 'clamp'})
const translateY = animation.y.interpolate({inputRange:[0,screenHeight - boxHeight],outputRange:[0,screenHeight - boxHeight], extrapolate: 'clamp'})

return(<View style={[styles.box,{transform:[{translateX},{translateY}]}]} />)