使用ViewDragHelp实现ImageView拖动超过屏幕1/2回到屏幕左边，否则到右边，还有一个就是还能实现点击的效果

首先，来看看效果图

完成如上效果主要需要一个类

public class DragView extends LinearLayout {
    private ViewDragHelper mViewDragHelper;
    private Point initPoint;
    private View autoTextView;

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

    private void initDragHelper() {
        mViewDragHelper = ViewDragHelper.create(DragView.this, 1.0f, mDragCallback);
        initPoint = new Point();
    }

    /**
     * ViewDragHelper回调接口
     */
    private ViewDragHelper.Callback mDragCallback = new ViewDragHelper.Callback() {
        @Override
        public boolean tryCaptureView(View child, int pointerId) {
            return true;
        }

        @Override
        public int clampViewPositionHorizontal(View child, int left, int dx) {// 水平拖动
            final int leftPadding = getPaddingLeft();
            final int rightPadding = getWidth() - child.getWidth() - leftPadding;
            final int newLeft = Math.min(Math.max(left, leftPadding), rightPadding);
            return newLeft;
        }

        @Override
        public int clampViewPositionVertical(View child, int top, int dy) {//竖直拖动
            final int topPadding = getPaddingTop();
            final int bottomPadding = getHeight() - child.getHeight() - topPadding;
            final int newTop = Math.min(Math.max(top, topPadding), bottomPadding);
            return newTop;
        }

        @Override
        public void onViewReleased(View releasedChild, float xvel, float yvel) {//拖动结束后
            super.onViewReleased(releasedChild, xvel, yvel);
            if (releasedChild == autoTextView && releasedChild.getLeft()  < (getWidth()/2)){
                mViewDragHelper.smoothSlideViewTo(releasedChild,initPoint.x,initPoint.y);//平滑移动
                ViewCompat.postInvalidateOnAnimation(DragView.this);
            }
        }
    };

    @Override
    public boolean onInterceptHoverEvent(MotionEvent event) {//拦截事件
        return mViewDragHelper.shouldInterceptTouchEvent(event);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {//消费事件
        mViewDragHelper.processTouchEvent(event);
        return true;
    }

    @Override
    public void computeScroll() {
        super.computeScroll();
        if (mViewDragHelper.continueSettling(true)) {//不停计算位置后，自动移动
            ViewCompat.postInvalidateOnAnimation(DragView.this);//重新绘制
        }
    }
    /**
     * 完成解析布局xml文件
     */
    @Override
    protected void onFinishInflate() {
        super.onFinishInflate();
        autoTextView =  getChildAt(0);
    }
    /**
     * 布局
     */
    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        super.onLayout(changed, l, t, r, b);
        initPoint.x = autoTextView.getLeft();
        initPoint.y = autoTextView.getTop();
    }
}

然后就可以拿来使用了

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ImageView iv=(ImageView)findViewById(R.id.iv);
        iv.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(MainActivity.this, "点击了该图标", Toast.LENGTH_SHORT).show();
            }
        });
    }

需要注意的是需要在布局文件中换成自定义的

<?xml version="1.0" encoding="utf-8"?>
<com.jhy.test4.DragView xmlns:android="http://schemas.android.com/apk/res/android"
                android:layout_width="match_parent"
                android:layout_height="match_parent">
    <ImageView
        android:id="@+id/iv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:src="@mipmap/ic_launcher_round"
        android:layout_marginRight="5dp"
        android:layout_marginTop="250dp"
        android:padding="1dp"/>
</com.jhy.test4.DragView>

然后就大功告成了

源码下载地址：http://download.youkuaiyun.com/detail/k2514091675/9900149