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
第一张图片是拖拽之前的效果图，第二张图片是拖拽后的效果图
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);
}
};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;
}
/******************************************************************************/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
}
});