Recyclerview现在基本已经替代Listview了，RecyclerView也越来越好用了  当我们有实现条目的拖拽排序和侧滑删除时  可以直接时候Recyclerview提供的API就可以直接实现了

先贴上主要代码

private void initveiw() {

ArrayList items = new ArrayList<>(Arrays.asList("itme1", "item2", "itme3", "item4", "item5", "item6", "item7", "item8", "itme9", "item10", "itme11", "item12", "item13", "item14", "item15", "item16"));

recyclerView.setLayoutManager(new LinearLayoutManager(this,LinearLayoutManager.VERTICAL,false));

SimpleAdapter adapter = new SimpleAdapter(items);

recyclerView.setAdapter(adapter);

ItemTouchHelper helper = new ItemTouchHelper(new MyItemTouchCallback(adapter));

helper.attachToRecyclerView(recyclerView);

}

public class MyItemTouchCallback extends ItemTouchHelper.Callback{

private SimpleAdapter adapter;

public MyItemTouchCallback(SimpleAdapter adapter) {

this.adapter = adapter;

}

@Override

public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {

int dragFlag;

int swipeFlag;

RecyclerView.LayoutManager manager = recyclerView.getLayoutManager();

if (manager instanceof GridLayoutManager){

dragFlag = ItemTouchHelper.DOWN | ItemTouchHelper.UP | ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT;

swipeFlag = 0;

}else{

dragFlag = ItemTouchHelper.DOWN | ItemTouchHelper.UP;

swipeFlag = ItemTouchHelper.END | ItemTouchHelper.START;

}

return makeMovementFlags(dragFlag,swipeFlag);

}

@Override

public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {

int fromPosition = viewHolder.getAdapterPosition();

int toPosition = target.getAdapterPosition();

if (fromPosition < toPosition ){

for (int i = fromPosition ;i

Collections.swap(adapter.getDataList(),i,i+1);

}

}else{

for (int i= fromPosition; i>toPosition; i--){

Collections.swap(adapter.getDataList(),i ,i-1);

}

}

recyclerView.getAdapter().notifyItemMoved(fromPosition,toPosition);

return true;

}

@Override

public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {

int position = viewHolder.getAdapterPosition();

if (direction == ItemTouchHelper.END | direction==ItemTouchHelper.START){

adapter.getDataList().remove(position);

adapter.notifyItemRemoved(position);

}

}

@Override

public void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) {

super.onSelectedChanged(viewHolder, actionState);

if (actionState==ItemTouchHelper.ACTION_STATE_DRAG){

viewHolder.itemView.setBackgroundColor(Color.BLUE);

}

}

@Override

public void clearView(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {

super.clearView(recyclerView, viewHolder);

viewHolder.itemView.setBackgroundColor(0);

}

}

步骤：

创建 ItemTouchHelper 对象时候，需要我们传入一个实现了 ItemTouchHelper.Callback 接口的对象。而排序和删除的逻辑都封装在了这个 ItemTouchHelper.Callback 的对象里面了。

private void initveiw() {

ArrayList items = new ArrayList<>(Arrays.asList("itme1", "item2", "itme3", "item4", "item5", "item6", "item7", "item8", "itme9", "item10", "itme11", "item12", "item13", "item14", "item15", "item16"));

recyclerView.setLayoutManager(new LinearLayoutManager(this,LinearLayoutManager.VERTICAL,false));

SimpleAdapter adapter = new SimpleAdapter(items);

recyclerView.setAdapter(adapter);

ItemTouchHelper helper = new ItemTouchHelper(new MyItemTouchCallback(adapter));

helper.attachToRecyclerView(recyclerView);

}

实现ItemTouchHelper.Callback接口后有三个方法需要重写：

getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) ：设置滑动类型的标记。需要设置两种类型的 flag ，即 dragFlags 和 swipeFlags ，分别代表着拖拽标记和滑动标记。最后需要调用 makeMovementFlags(dragFlags,

swipeFlags)方法来合成返回。

onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) ：当用户拖拽列表某个 item 时会回调。很明显，拖拽排序的代码应该在这个方法中实现。

onSwiped(RecyclerView.ViewHolder viewHolder, int direction) ：当用户滑动列表某个 item 时会回调。所以侧滑删除的代码应该在这个方法中实现。

下面是重写的几个方法：

第一个，getMovementFlags方法

@Override

public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {

int dragFlag;

int swipeFlag;

RecyclerView.LayoutManager manager = recyclerView.getLayoutManager();

if (manager instanceof GridLayoutManager){

dragFlag = ItemTouchHelper.DOWN | ItemTouchHelper.UP | ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT;

swipeFlag = 0;

}else{

dragFlag = ItemTouchHelper.DOWN | ItemTouchHelper.UP;

swipeFlag = ItemTouchHelper.END | ItemTouchHelper.START;

}

return makeMovementFlags(dragFlag,swipeFlag);

}

这个方法里面根据LayoutManager分了两种情况，根据自己的情况去分

在GridLayoutManager中只能上下左右拖拽但是不能侧滑删除，所以swipFlag = 0；swipeFlag的值ItemTouchHelper.END是右滑删除，ItemTouchHelper.START是左滑删除

最后调用makeMovementFlags方法合成返回

第二个，onMove方法

@Override

public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {

int fromPosition = viewHolder.getAdapterPosition();

int toPosition = target.getAdapterPosition();

if (fromPosition < toPosition ){

for (int i = fromPosition ;i

Collections.swap(adapter.getDataList(),i,i+1);

}

}else{

for (int i= fromPosition; i>toPosition; i--){

Collections.swap(adapter.getDataList(),i ,i-1);

}

}

recyclerView.getAdapter().notifyItemMoved(fromPosition,toPosition);

return true;

}

这个方法是用户在拖拽 item 的时候调用。所以关于列表排序的代码应该写在这里。方法参数中的 viewHolder 代表的是用户当前拖拽的 item ，而 target 代表的是被用户拖拽所覆盖的那个 item 。所以在 onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) 方法中的逻辑就是把 fromPosition 至 toPosition 为止改变它们的位置。

第三个，onSwiped方法

@Override

public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {

int position = viewHolder.getAdapterPosition();

if (direction == ItemTouchHelper.END | direction==ItemTouchHelper.START){

adapter.getDataList().remove(position);

adapter.notifyItemRemoved(position);

}

}

这个方法是在用户侧滑的时候调用的 ，在里面对adapter的数据进行删除就可以了

最后两个方法

@Override

public void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) {

super.onSelectedChanged(viewHolder, actionState);

if (actionState==ItemTouchHelper.ACTION_STATE_DRAG){

viewHolder.itemView.setBackgroundColor(Color.BLUE);

}

}

@Override

public void clearView(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {

super.clearView(recyclerView, viewHolder);

viewHolder.itemView.setBackgroundColor(0);

}

}

就是优化的方法，第一个是选择条目改变状态，第二个是手指抬起之后恢复条目状态

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。