android中的recyclerview的基础学习（一）

1、用AndroidStudio开发的，在项目中导入jar包


问题：

1.）recyclerview导入包的问题

2. ) 

昨天demo报这个

 出现No layout manager attached; skipping layout错误

是没有设置LayoutManager 

原因是：

rv.setLayoutManager(new LinearLayoutManager(this));//这里用线性显示 类似于listview

2.代码

package com.example.administrator.recyclerview;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;

import java.util.ArrayList;
import java.util.List;

/**
* time:2017/1/4
*/
public class MainActivity extends AppCompatActivity {
private RecyclerView rv;
private RecyclerView.Adapter myAdapter;
private List<String> mDatas;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
rv = (RecyclerView) findViewById(R.id.rv);
//       initData();
//TODO
rv.setLayoutManager(new LinearLayoutManager(this));//这里用线性显示 类似于listview
myAdapter = new MyAdapter(this);
rv.setAdapter(myAdapter);
}

//    protected void initData() {
//        mDatas = new ArrayList<String>();
//        for (int i = 'A'; i < 'z'; i++) {
//            mDatas.add("" + (char) i);
//        }
//    }

}

3、adapter

package com.example.administrator.recyclerview;

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

/**
* Created by Administrator on 2017/1/4.
*/

class MyAdapter extends RecyclerView.Adapter {
Context context;

public MyAdapter(Context context) {
this.context = context;
}

@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = View.inflate(context,R.layout.item,null);
Holder holder = new Holder(view);
return holder;
}

@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {
final Holder h = (Holder) holder;
h.setData(position);
}

@Override
public int getItemCount() {
//  return list.size();
return 10;
}
}

class Holder extends RecyclerView.ViewHolder {
TextView mtv;

public Holder(View view) {
super(view);
mtv = (TextView) view.findViewById(R.id.tv);
}

public void setData(int position) {
//   mtv.setText(list.get(position).getName());
mtv.setText("wowo");
}
}

4、布局

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.administrator.recyclerview.MainActivity">

<android.support.v7.widget.RecyclerView
android:id="@+id/rv"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</RelativeLayout>

5、item布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/tv"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>