UITouch touchesMoved Finger Direction and Speed

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慢半拍i
慢半拍i 2020-12-31 07:42

How can I get Speed and Direction of finger movements in touchmoved function?

I want to get the finger speed and finger direction and apply it in a UIView class dire

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  •  爱一瞬间的悲伤
    2020-12-31 08:16

    Direction will be determined from the values of "location" and "prevLocation" in touchesMoved. Specifically, location will contain the new point of the touch. For example:

    if (location.x - prevLocation.x > 0) {
        //finger touch went right
    } else {
        //finger touch went left
    }
    if (location.y - prevLocation.y > 0) {
        //finger touch went upwards
    } else {
        //finger touch went downwards
    }
    

    Now touchesMoved will get called many times for a given finger movement. It will be key to your code to compare an initial value when the finger first touches the screen, with a value of the CGPoint when the movement is finally complete.

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