android - 使用 MotionEvent.ACTION_MOVE 制作像主屏幕一样的 ViewFlipper

Question

好的，我有一个 ViewFlipper，其中嵌套了三个 LinearLayouts。它默认显示第一个。这段代码:

// Assumptions in my Activity class:
// oldTouchValue is a float
// vf is my view flipper
@Override
public boolean onTouchEvent(MotionEvent touchEvent) {
  switch (touchEvent.getAction()) {
    case MotionEvent.ACTION_DOWN: {
      oldTouchValue = touchEvent.getX();
      break;
    }
    case MotionEvent.ACTION_UP: {
      float currentX = touchEvent.getX();
      if (oldTouchValue < currentX) {
        vf.setInAnimation(AnimationHelper.inFromLeftAnimation());
        vf.setOutAnimation(AnimationHelper.outToRightAnimation());
        vf.showNext();
      }
      if (oldTouchValue > currentX) {
        vf.setInAnimation(AnimationHelper.inFromRightAnimation());
        vf.setOutAnimation(AnimationHelper.outToLeftAnimation());
        vf.showPrevious();
      }
      break;
    }
    case MotionEvent.ACTION_MOVE: {
      // TODO: Some code to make the ViewFlipper
      // act like the home screen.
      break;
    }
  }
  return false;
}

public static class AnimationHelper {
  public static Animation inFromRightAnimation() {
    Animation inFromRight = new TranslateAnimation(
    Animation.RELATIVE_TO_PARENT, +1.0f,
    Animation.RELATIVE_TO_PARENT, 0.0f,
    Animation.RELATIVE_TO_PARENT, 0.0f,
    Animation.RELATIVE_TO_PARENT, 0.0f);
    inFromRight.setDuration(350);
    inFromRight.setInterpolator(new AccelerateInterpolator());
    return inFromRight;
  }

  public static Animation outToLeftAnimation() {
    Animation outtoLeft = new TranslateAnimation(
    Animation.RELATIVE_TO_PARENT, 0.0f,
    Animation.RELATIVE_TO_PARENT, -1.0f,
    Animation.RELATIVE_TO_PARENT, 0.0f,
    Animation.RELATIVE_TO_PARENT, 0.0f);
    outtoLeft.setDuration(350);
    outtoLeft.setInterpolator(new AccelerateInterpolator());
    return outtoLeft;
  }

  // for the next movement
  public static Animation inFromLeftAnimation() {
    Animation inFromLeft = new TranslateAnimation(
    Animation.RELATIVE_TO_PARENT, -1.0f,
    Animation.RELATIVE_TO_PARENT, 0.0f,
    Animation.RELATIVE_TO_PARENT, 0.0f,
    Animation.RELATIVE_TO_PARENT, 0.0f);
    inFromLeft.setDuration(350);
    inFromLeft.setInterpolator(new AccelerateInterpolator());
    return inFromLeft;
  }

  public static Animation outToRightAnimation() {
    Animation outtoRight = new TranslateAnimation(
    Animation.RELATIVE_TO_PARENT, 0.0f,
    Animation.RELATIVE_TO_PARENT, +1.0f,
    Animation.RELATIVE_TO_PARENT, 0.0f,
    Animation.RELATIVE_TO_PARENT, 0.0f);
    outtoRight.setDuration(350);
    outtoRight.setInterpolator(new AccelerateInterpolator());
    return outtoRight;
  }
}

... 处理 View 翻转，但动画非常“开/关”。我想知道是否有人可以帮助我完成最后一部分。假设我可以访问 LinearLayouts，有没有一种方法可以根据 deltaX 和 deltaY 设置布局的位置？

有人给了我this link并说我应该引用 applyTransformation 方法以获取有关如何执行此操作的提示，但我不知道如何重复相同的行为。

Answer 1

在移动手指的同时移动 View 很容易:

case MotionEvent.ACTION_MOVE:
    final View currentView = vf.getCurrentView();
    currentView.layout((int)(touchEvent.getX() - oldTouchValue), 
            currentView.getTop(), currentView.getRight(), 
            currentView.getBottom());
break;

现在这只会移动当前 View ，不会移动邻居。我还没有测试过，但是这些可能可以通过 getChildAt 获得:

vf.getChildAt(vf.getDisplayedChild() - 1); // previous
vf.getChildAt(vf.getDisplayedChild() + 1); // next

希望对您有所帮助。