1、概述

项目要求一个可拖拽的gridview功能，主要是可以长按图标，然后手指移动到对应位置，松开后图标移动到对应手指松开的位置，后面的图标依次挪移一个position。

2、效果图

3、重写dispatchTouchEvent方法

/**      * 长按的Runnable      */      private Runnable mLongClickRunable = new Runnable() {          @Override          public void run() {              isDrag = true;              //mVibrator.vibrate(200);              //隐藏该item              mDragView.setVisibility(INVISIBLE);              //在点击的地方创建并显示item镜像              createDragView(mDragBitmap, mDownX, mDownY);          }      };      /**      * 当moveY的值大于向上滚动的边界值，触发GridView自动向上滚动      * 当moveY的值小于向下滚动的边界值，触犯GridView自动向下滚动      * 否则不进行滚动      */      private Runnable mScrollRunbale = new Runnable() {          @Override          public void run() {              int scrollY = 0;              if (mMoveY > mUpScrollBorder){                  scrollY = mSpeed;                  mHandler.postDelayed(mScrollRunbale,25);              }else if (mMoveY < mDownScrollBorder){                  scrollY = -mSpeed;                  mHandler.postDelayed(mScrollRunbale,25);              }else {                  scrollY = 0;                  mHandler.removeCallbacks(mScrollRunbale);              }              smoothScrollBy(scrollY,10);          }      };  复制代码

5、对外暴露的方法

/************************对外提供的接口***************************************/      public boolean isDrag() {          return isDrag;      }      //设置是否可拖拽      public void setDrag(boolean drag) {          isDrag = drag;      }      public long getDragResponseMs() {          return mDragResponseMs;      }      //设置长按响应时长      public void setDragResponseMs(long mDragResponseMs) {          this.mDragResponseMs = mDragResponseMs;      }      public void setOnItemChangeListener(OnItemChangeListener changeListener) {          this.changeListener = changeListener;      }      /******************************************************************************/  复制代码

6、如何在页面中调用

DragGridView dragGridView = findViewById(R.id.dgv);      dragGridView.setNumColumns(NUM_COLUMNS);      initData();      mMoreColorTypeAdapter = new MoreColorTypeAdapter(this, true, data, NUM_COLUMNS);      dragGridView.setAdapter(mMoreColorTypeAdapter);      dragGridView.setOnItemClickListener(this);      dragGridView.setOnItemChangeListener(new DragGridView.OnItemChangeListener() {          @Override          public void onChange(int from, int to) {              Data dataBean = data.get(from);              //直接交互              //Collections.swap(dataSourceList,from,to);              //非直接交互 这里的处理需要注意下 排序交换              if(from < to){                  for(int i = from; i < to; i++){                      Collections.swap(data, i, i + 1);                  }              }else if(from > to){                  for(int i = from; i > to; i--){                      Collections.swap(data, i, i - 1);                  }              }              data.set(to, dataBean);              mMoreColorTypeAdapter.notifyDataSetChanged();          }          @Override          public void onStop() {              //拖动停止          }      });  复制代码