Android 动画下拉并返回

Hy，我正在尝试实现这个动画。有人能帮我吗

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我曾尝试使用pull刷新库，但结果并不完全符合预期。谢谢大家!

在android中向ScrollView添加效果反弹

步骤1：在package com.base.view中创建新文件BounceScrollView

公共类BouncyScroll扩展了ScrollView{ 私有滚动回调mCallbacks

private static final int MAX_Y_OVERSCROLL_DISTANCE = 200;

private Context mContext;
private int mMaxYOverscrollDistance;

public BouncyScroll(Context context, AttributeSet attrs) {
    super(context, attrs);
    this.mContext = context;
    initBounceScrollView();
}

@Override
protected void onScrollChanged(int l, int t, int oldl, int oldt) {
    super.onScrollChanged(l, t, oldl, oldt);
    if (mCallbacks != null) {
        mCallbacks.onScrollChanged(l, t, oldl, oldt);
    }
}

@Override
public int computeVerticalScrollRange() {
    return super.computeVerticalScrollRange();
}

public void setCallbacks(ScrollCallbacks listener) {
    mCallbacks = listener;
}

private void initBounceScrollView() {
    // get the density of the screen and do some maths with it on the max
    // overscroll distance
    // variable so that you get similar behaviors no matter what the screen
    // size

    final DisplayMetrics metrics = mContext.getResources()
            .getDisplayMetrics();
    final float density = metrics.density;

    mMaxYOverscrollDistance = (int) (density * MAX_Y_OVERSCROLL_DISTANCE);

}

@Override
public void draw(Canvas canvas) {
    super.draw(canvas);
}

static interface ScrollCallbacks {
    public void onScrollChanged(int l, int t, int oldl, int oldt);
}

@SuppressLint("NewApi")
@Override
protected boolean overScrollBy(int deltaX, int deltaY, int scrollX,
        int scrollY, int scrollRangeX, int scrollRangeY,
        int maxOverScrollX, int maxOverScrollY, boolean isTouchEvent) {
    // This is where the magic happens, we have replaced the incoming
    // maxOverScrollY with our own custom variable mMaxYOverscrollDistance;
    return super.overScrollBy(deltaX, deltaY, scrollX, scrollY,
            scrollRangeX, scrollRangeY, maxOverScrollX,
            mMaxYOverscrollDistance, isTouchEvent);
}

} 第2步：在您的布局中，请更改

<ScrollView 
   android:id="@+id/list"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
/>

到

谢谢您的回答，但我仍然有一些与overScrollBy方法相关的问题。它似乎没有在ScrollView中定义。有什么办法让它工作吗？这对我来说很有用。。。。你把卷轴改到你的课上了吗？是的。我完全按照你说的做了。你使用的目标API是什么？它是API。谢谢，它起作用了

<com.base.view.BounceScrollView 
   android:id="@+id/list"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
/>