Android项目中怎么实现一个可拖拽界面

本篇文章为大家展示了Android项目中怎么实现一个可拖拽界面，内容简明扼要并且容易理解，绝对能使你眼前一亮，通过这篇文章的详细介绍希望你能有所收获。

以自定义ImageView为例：

public class FloatingImageView extends ImageView{  public FloatingImageView(Context context) {    super(context);  }  public FloatingImageView(Context context, AttributeSet attrs) {    super(context, attrs);  }  public FloatingImageView(Context context, AttributeSet attrs, int defStyleAttr) {    super(context, attrs, defStyleAttr);  }  @Targetapi(Build.VERSioN_CODES.LOLLIPOP)  public FloatingImageView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {    super(context, attrs, defStyleAttr, defStyleRes);  }  int startX;  int startY;  int left;  int top;  int[] temp = new int[]{ 0, 0 };  @Override  public boolean onTouchEvent(MotionEvent event) {    boolean isMove = false;    int x = (int) event.getRawX();    int y = (int) event.getRawY();    switch (event.getAction()){      case MotionEvent.ACTION_DOWN: // touch down so check if the        startX = x;        startY = y;        temp[0] = (int) event.getX();        temp[1] = y - getTop();        break;      case MotionEvent.ACTION_MOVE: // touch drag with the ball        left = x - temp[0];        top = y - temp[1];        if(left < 0){//控制左边界不超出          left = 0;        }        layout(left, top, left + getWidth(),top + getHeight());//自由拖拽        break;      case MotionEvent.ACTION_UP:        if (Math.abs(x - startX) > 2 || Math.abs(y - startY) > 2){//判断是否移动,再一定范围内不算是移动，解决触发事件冲突          //将最后拖拽的位置定下来，否则页面刷新渲染后按钮会自动回到初始位置          //注意父容器          RelativeLayout.LayoutParams lp = (RelativeLayout.LayoutParams) getLayoutParams();          lp.setMargins(left, top,0,0);          setLayoutParams(lp);          //确定是拖拽          isMove = true;         }        break;    }    return isMove &#63; true : super.onTouchEvent(event);   }}