#鸿蒙通关秘籍#如何在HarmonyOS中实现标题下拉缩放的效果？

handleTouchEvent(event: TouchEvent): void {
  switch (event.type) {
    case TouchType.Down:
      downY = event.touches[0].y;
      lastMoveY = event.touches[0].y;
      isMoving = true;
      duration = Constants.ANIMATE_DURATION_DRAG;
      break;
    case TouchType.Move:
      const delta = event.touches[0].y - lastMoveY;
      offsetY = event.touches[0].y - downY;
      if (delta < 0) {
        heightValue = $r('app.string.memo_area_height_before');
        isExpanded = false;
        atStart = false;
      }
      if (delta > 0 && atStart) {
        animateToThrottle(() => {
          heightValue = $r('app.string.memo_area_height_after');
          isExpanded = true;
        }, 1000);
      }
      lastMoveY = event.touches[0].y;
      break;
    case TouchType.Up:
    case TouchType.Cancel:
      isMoving = false;
      duration = Constants.ANIMATE_DURATION_BACK;
      break;
  }
}
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