界面的设置 
<ImageView
        android:id="@+id/picture"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:layout_gravity="center"/>
        <Button
            android:id="@+id/btn"
            android:layout_gravity="center"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="out"/>

对其功能的实现：
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    picture = (ImageView) findViewById(R.id.picture);
    btn = (Button) findViewById(R.id.btn);
    this.btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (btn.isClickable());
             Toast.makeText(MainActivity.this,"再按一次退出按钮",Toast.LENGTH_LONG).show();


        }
    });

}

public boolean onTouchEvent(MotionEvent event) {
    if (event.getAction() == MotionEvent.ACTION_MOVE) {
        float x = event.getX();
        float y = event.getY();
        String pos = "x坐标" + x + "y坐标" + y;
        Toast.makeText(this, pos, Toast.LENGTH_LONG).show();
        picture.setImageResource(R.drawable.youcaihua);
        picture.setX(x - 100);
        picture.setY(y - 100);
    }
    return super.onTouchEvent(event);
}


private long exitTime = 0;

任务二