RecyclerView实现拖拽排序侧滑删除效果
事先说明:
RecyclerView是ListView的升级版,使用起来比ListView更规范,而且功能和动画可以自己添加,极容易扩展,同样也继承了ListView复用convertView和ViewHolder的优点。
思路分析:
1、导包、在布局中使用RecyclerView
2、需要一个JavaBean用来存储展示信息
3、需要一个填充RecyclerView的布局文件
4、在代码中找到RecyclerView,并为其绑定Adapter和触摸事件
5、适配器的编写、触摸事件的处理
总体上跟ListView是一样的,就是换了一种代码风格
思路图解:
效果一(线性布局): 效果二(网格布局):
步骤一:RecyclerView是在support.v7包,Android Studio则是recyclerview这个包
步骤二:创建布局文件,使用recyclerview
public class Message {
private String username;
private String time;
private String message;
private int img_id;
public Message(String username, String time, String message, int img_id) {
this.username = username;
this.time = time;
this.message = message;
this.img_id = img_id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getTime() {
return time;
}
public void setTime(String time) {
this.time = time;
}
public String getMessage() {
return message;
}
public void setMessage(String message) {
this.message = message;
}
public int getImg_id() {
return img_id;
}
public void setImg_id(int img_id) {
this.img_id = img_id;
}
}
步骤五:创建RecycleView的Adapter
public class RecycleViewAdapter extends RecyclerView.Adapter {
private List list;
public RecycleViewAdapter(List list) {
this.list = list;
}
class MyViewHolder extends RecyclerView.ViewHolder {
private TextView tv_username, tv_time, tv_message;
private ImageView iv_icon;
public MyViewHolder(View itemView) {
super(itemView);
tv_username = (TextView) itemView.findViewById(R.id.tv_username);
tv_time = (TextView) itemView.findViewById(R.id.tv_time);
tv_message = (TextView) itemView.findViewById(R.id.tv_message);
iv_icon = (ImageView) itemView.findViewById(R.id.iv_icon);
}
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.recycle_item, parent, false);
return new MyViewHolder(view);
}
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
Message msg = list.get(position);
holder.tv_username.setText(msg.getUsername());
holder.tv_time.setText(msg.getTime());
holder.tv_message.setText(msg.getMessage());
holder.iv_icon.setBackgroundResource(msg.getImg_id());
}
@Override
public int getItemCount() {
return list.size();
}
}
思路分析:
这里的实现的形式跟ListView有点不一样,它继承的不是BaseAdapter,继承的是RecycleView的Adapter,并且泛型填一个ViewHolder,这个ViewHolder在该类中作为内部类实现,其他的实现跟ListView是一样的步骤六:代码中使用
public class MainActivity extends AppCompatActivity {
private RecyclerView rv;
private RecycleViewAdapter adapter;
private List list;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initData();
rv = (RecyclerView) findViewById(R.id.rv);
rv.setLayoutManager(new LinearLayoutManager(this));
adapter = new RecycleViewAdapter(list);
rv.setAdapter(adapter);
}
private void initData() {
list = new ArrayList<>();
list.add(new Message("Hensen", "下午1:22", "老板:哈哈哈", R.drawable.icon1));
list.add(new Message("流年不利", "早上10:31", "美女:呵呵哒", R.drawable.icon2));
list.add(new Message("1402", "下午1:55", "嘻嘻哈哈", R.drawable.icon3));
list.add(new Message("Unstoppable", "下午4:32", "美美哒", R.drawable.icon4));
list.add(new Message("流年不利", "晚上7:22", "萌萌哒", R.drawable.icon2));
list.add(new Message("Hensen", "下午1:22", "哈哈哈", R.drawable.icon1));
list.add(new Message("Hensen", "下午1:22", "哈哈哈", R.drawable.icon1));
list.add(new Message("Hensen", "下午1:22", "哈哈哈", R.drawable.icon1));
}
}
和ListView不同的是,这里必须写这一句,不然View显示不出来,也是这一句话可以控制布局为LinearLayout或者是GridView或者是瀑布流布局
rv.setLayoutManager(new LinearLayoutManager(this));
//为RecycleView绑定触摸事件
ItemTouchHelper helper = new ItemTouchHelper(new ItemTouchHelper.Callback() {
@Override
public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
//首先回调的方法 返回int表示是否监听该方向
int dragFlags = ItemTouchHelper.UP|ItemTouchHelper.DOWN;//拖拽
int swipeFlags = ItemTouchHelper.LEFT|ItemTouchHelper.RIGHT;//侧滑删除
return makeMovementFlags(dragFlags,swipeFlags);
}
@Override
public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
//滑动事件
Collections.swap(list,viewHolder.getAdapterPosition(),target.getAdapterPosition());
adapter.notifyItemMoved(viewHolder.getAdapterPosition(),target.getAdapterPosition());
return false;
}
@Override
public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {
//侧滑事件
list.remove(viewHolder.getAdapterPosition());
adapter.notifyItemRemoved(viewHolder.getAdapterPosition());
}
@Override
public boolean isLongPressDragEnabled() {
//是否可拖拽
return true;
}
});
helper.attachToRecyclerView(rv);
思路分析:我们规定拖拽的动作是上下拖拽,而删除效果是左右删除。在拖拽事件中,就是通过集合的一个交换然后实现布局的更新,这里RecyclerView的adapter都帮我们实现好了,用起来很简单,而删除事件就是集合删除一个数据,然后更新布局。
如果要实现效果二,可以做出类似桌面拖拽排序的效果,这个就请大家自由发挥吧,实现效果二,只要在效果一的基础上修改两处代码即可:
// rv.setLayoutManager(new LinearLayoutManager(this));
rv.setLayoutManager(new GridLayoutManager(this,2));
//首先回调的方法 返回int表示是否监听该方向
int dragFlags = ItemTouchHelper.UP|ItemTouchHelper.DOWN|ItemTouchHelper.LEFT|ItemTouchHelper.RIGHT;//拖拽
int swipeFlags = 0;//侧滑删除
return makeMovementFlags(dragFlags,swipeFlags);
// rv.setLayoutManager(new GridLayoutManager(this,2));
rv.setLayoutManager(new StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.VERTICAL));
源码是AndroidStudio的Module,建议用Import Module导入源码下载