Recyclerview--两行代码轻松添加点击选中效果

• 前言

简单的实现Recyclerview选中效果，开发中很常见，比如点击item，后面加上选择按钮，亦或者类似CheckBox效果，可以用很少几行代码实现

• 实现

直接贴代码，布局很简单，一个文字，后面一个选择按钮

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="45dp"
    android:layout_margin="5dp"
    android:gravity="center"
    android:orientation="horizontal">

    <TextView
        android:id="@+id/tv_state"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="center"
        android:layout_marginLeft="5dp"
        android:layout_marginRight="10dp"
        android:gravity="center"
        android:textColor="@color/state_visibility"
        android:textSize="18sp"
        tools:text="@string/state" />

    <ImageView
        android:id="@+id/iv_selected"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
          android:visibility="invisible"
        android:src="@drawable/icon_selected" />
</LinearLayout>```

实现选择功能，在Adapter中

/**

• Author : ddz
• Creation time : 2017/3/1 17:08
• Fix time : 2017/3/1 17:08
  */

public class CheckStateAdapter extends RecyclerView.Adapter<CheckStateAdapter.StateHolder> {

private Context context;
private String[] arrayState;
private int selectedPosition = -5; //默认一个参数

public CheckStateAdapter(@NonNull String[] arrayState, Context context) {
    this.context = context;
    this.arrayState = arrayState;
}

@Override
public StateHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    return new StateHolder(LayoutInflater.from(context).inflate(R.layout.state_item, parent, false));
}

@Override
public void onBindViewHolder(StateHolder holder, int position) {
    if (null == arrayState) return;
    holder.itemView.setSelected(selectedPosition == position);
    if (selectedPosition == position) {
        holder.ivSelected.setVisibility(View.VISIBLE);
    } else {
        holder.ivSelected.setVisibility(View.INVISIBLE);
    }
    holder.tvState.setText(arrayState[position]);
    holder.itemView.setOnClickListener(view -> {
        onItemClickListener.OnItemClick(view, holder, holder.getAdapterPosition()); 
        selectedPosition = position; //选择的position赋值给参数，
        notifyItemChanged(selectedPosition);//刷新当前点击item
    });
}



@Override
public int getItemCount() {
    return arrayState.length == 0 ? 0 : arrayState.length;
}

public void updateData(String[] airPortModels) {
    if (null != arrayState) {
        selectedPosition = -5;
        arrayState = null;
        arrayState = airPortModels;
        notifyDataSetChanged();
    }
}


public class StateHolder extends RecyclerView.ViewHolder {
    @BindView(R.id.tv_state)
    TextView tvState;
    @BindView(R.id.iv_selected)
    ImageView ivSelected;

    public StateHolder(View itemView) {
        super(itemView);
        ButterKnife.bind(this, itemView);
    }
}

private OnItemClickListener onItemClickListener;

public interface OnItemClickListener {  //定义接口，实现Recyclerview点击事件
    void OnItemClick(View view, StateHolder holder, int position);
}


public void setOnItemClickListener(OnItemClickListener onItemClickListener) {   //实现点击
    this.onItemClickListener = onItemClickListener;
}

}

item点击时，就可以简单实现点击选中效果