Question

我写了这个代码用于放大/缩小，它应该只用两个手指，但它适用于两个！并且通常反应奇怪！任何人都知道为什么？

boolean surfaceTouchEvent(MotionEvent event) {
  pointNum=event.getPointerCount();
  switch (event.getAction() & MotionEvent.ACTION_MASK) {
  case MotionEvent.ACTION_POINTER_DOWN:
    x1=event.getX(0);
    x2=event.getX(1);
    y1=event.getY(0);
    y2=event.getY(1);
    z4 = dist(x1, y1, x2, y2);
    println("z4 is : "+z4);
    mode = true; // pinch
    break;
  case MotionEvent.ACTION_MOVE:
    if (mode = false) {
      x3=event.getX(0)-x0;
      y3=event.getY(0)-y0;
    }  

    if (mode = true) {
      x1=event.getX(0);
      x2=event.getX(1);
      y1=event.getY(0);
      y2=event.getY(1);
      float z3 = dist(x1, y1, x2, y2);
      println("z3is :" + z3);
      if ( z3 < z4 ) { 
        zoom = z3/z4;
        println(" zoom :" + zoom);
      }
      else if ( z3 > z4) {
        zoom = z3/z4;
        println(" zoom :" + zoom);

      }
    }
    break;
  }
  return super.surfaceTouchEvent(event);
}

Answer 1

不知道原因，但是如果你想要用于缩放缩放的代码，那么这里是一个链接。它对我来说很好。

Android Image View Pinch Zooming

android：zoom反应奇怪

1 个答案: