實現ListView頭部圖片拉昇方大鬆手回彈

/**
 * Created by Administrator on 2017-08-01.
 */
public class MyListView extends ListView {

    private ImageView mImage;
    private int mOriginalHeight;
    private int drawableHeight;


    public MyListView(Context context) {
        super(context);
    }

    public MyListView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public MyListView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    /**
     * 設置ImageView 圖片，
     * 獲得圖片的高度和ImageView的初始高度
     *
     * @param image
     */
    public void setParallaxImage(ImageView image) {
        this.mImage = image;
        mOriginalHeight = mImage.getHeight();
        drawableHeight = mImage.getDrawable().getIntrinsicHeight();
    }

    @Override
    protected boolean overScrollBy(int deltaX, int deltaY, int scrollX, int scrollY, int scrollRangeX, int scrollRangeY, int maxOverScrollX, int maxOverScrollY, boolean isTouchEvent) {

        if (isTouchEvent && deltaY < 0) {

            if (mImage.getHeight() <= drawableHeight) {
                int newHeight = (int) (mImage.getHeight() + Math.abs(deltaY / 3.0f));
                mImage.getLayoutParams().height = newHeight;
                mImage.requestLayout();
            }

        }
        return super.overScrollBy(deltaX, deltaY, scrollX, scrollY, scrollRangeX, scrollRangeY, maxOverScrollX, maxOverScrollY, isTouchEvent);
    }

    /**
     * 鬆開手回彈
     * @param ev ev
     * @return boolean
     */
    @Override
    public boolean onTouchEvent(MotionEvent ev) {

        switch (ev.getActionMasked()){

            case MotionEvent.ACTION_UP:

                final int startHeight = mImage.getHeight();
                final int endHeight = mOriginalHeight;
                ResetAnimation animation = new ResetAnimation(mImage, startHeight, endHeight);
                startAnimation(animation);
                break;
        }
        return super.onTouchEvent(ev);
    }


    public class ResetAnimation extends Animation{

        private final ImageView mImage;
        private final int startHeight;
        private final int endHeight;
        public ResetAnimation(ImageView image,int startHeight,int endHeight) {

            this.mImage=image;
            this.startHeight=startHeight;
            this.endHeight=endHeight;

            setInterpolator(new OvershootInterpolator());

            setDuration(500);

        }

        @Override
        protected void applyTransformation(float interpolatedTime, Transformation t) {
            Integer newHeight=evaluate(interpolatedTime,startHeight,endHeight);
            mImage.getLayoutParams().height=newHeight;
            mImage.requestLayout();
            super.applyTransformation(interpolatedTime, t);
        }
        /**
         * 類型估值器
         * @param fraction
         * @param startValue
         * @param endValue
         * @return
         */
        public Integer evaluate(float fraction, Integer startValue, Integer endValue) {
            int startInt = startValue;
            return (int)(startInt + fraction * (endValue - startInt));
        }
    }


}

public class OverScrollByActivity extends AppCompatActivity {

    private MyListView mListView;

    ArrayList<String> mData=new ArrayList<>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_over_scroll_by);

        mListView = (MyListView) findViewById(R.id.listView);
        final View mHeaderView = View.inflate(this, R.layout.view_header, null);
        final ImageView mImage = (ImageView) mHeaderView.findViewById(R.id.iv);
        mListView.addHeaderView(mHeaderView);
        mListView.setOverScrollMode(View.OVER_SCROLL_NEVER);
        mHeaderView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {

            @Override
            public void onGlobalLayout() {
                // 當佈局填充結束之後, 此方法會被調用
                mListView.setParallaxImage(mImage);
                mHeaderView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
            }
        });
        initData();
        initFill();
    }

    private void initFill() {

        mListView.setAdapter(new ArrayAdapter<>(this,android.R.layout.simple_list_item_1,mData));
        // 加Header

    }

    private void initData(){

        mData.add("android");
        mData.add("ios");
        mData.add("xml");
        mData.add("java");
        mData.add("android");
        mData.add("ios");
        mData.add("xml");
        mData.add("java");
        mData.add("android");
        mData.add("ios");
        mData.add("xml");
        mData.add("java");
    }
}

R.layout.activity_over_scroll_by

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="mdks.andy.activity.OverScrollByActivity">
    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <mdks.andy.view.MyListView
            android:id="@+id/listView"
            android:divider="#e43435"
            android:dividerHeight="2dp"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            />

    </LinearLayout>
</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <ImageView
        android:id="@+id/iv"
        android:layout_width="match_parent"
        android:layout_height="160dp"
        android:scaleType="centerCrop"
        android:src="@mipmap/picture"
        />

</LinearLayout>