[2017-7-26]Android Learning Day4

RecycleView

恩，学习Fragment的过程中的一个小实践居然用到了RecycleView！坑了我好久有木有！！好气哦，从昨晚到现在。（现在也还是一头雾水，不过照搬也会用了）

这是第一版的代码，都写在 MainActivity.java 里了。

 public class MainActivity extends AppCompatActivity {

     private RecyclerView rv;
     private ArrayList<String> datas = new ArrayList<String>();

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);

         rv = new RecyclerView(this);

         createData(datas);

         setContentView(rv);

         rv.setLayoutManager(new LinearLayoutManager(this));

         rv.setAdapter(new RecyclerView.Adapter() {

             //重写你想要的RecyclerView中的每一项所含有的内容
             class myViewHolder extends RecyclerView.ViewHolder {
                 private TextView tv;

                 public myViewHolder(TextView itemView) {
                     super(itemView);
                     tv = itemView;
                     tv.setTextSize(28);
                 }

                 public TextView getTv() {
                     return tv;
                 }
             }

             //创建RecycleView中每一项的内容
             @Override
             public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
                 return new myViewHolder(new TextView(parent.getContext()));
             }

             //创建的的每一项与布局绑定并设置数据
             @Override
             public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
                 ((myViewHolder)holder).getTv().setText(datas.get(position));
             }

             //获取RecycleView的长度
             @Override
             public int getItemCount() {
                 System.out.println("--------------------------------------->"+datas.size());
                 return datas.size();
             }
         });
     }

     public void createData(ArrayList<String> data) {

         for(char i='A';i<='Z';i++)
         {
             data.add(String.valueOf(i));
         }
     }

 }

接下里是升级后的，把Adapter单独提出来写,也是最重要的部分！MyAdapter.java

 package com.liwenchi.learnrv;

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

 /**
  * Created by VULCAN on 2017/7/26.
  */
 class MyAdapter extends RecyclerView.Adapter {

     private CellData[] data = new CellData[]{new CellData("为什么Django框架仍然统治着Python开发世界","因为它真的很厉害"),new CellData("用Python分析购物篮","一种有用的技术成为关联分析...")};

     //重写你想要的RecyclerView中的每一项所含有的内容
     class myViewHolder extends RecyclerView.ViewHolder {
         private View root;
         private TextView tvTitle;
         private TextView tvContent;

         public myViewHolder(View root) {
             super(root);

             tvTitle = (TextView) root.findViewById(R.id.tvTitle);
             tvContent = (TextView) root.findViewById(R.id.tvContent);
         }

         public TextView getTvTitle() {
             return tvTitle;
         }

         public TextView getTvContent() {
             return tvContent;
         }
     }

     //创建RecycleView中每一项的内容
     @Override
     public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
         //创建一个布局解释器
         return new myViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.list_cell, null));
     }

     //创建的的每一项与布局绑定并设置数据
     @Override
     public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
         ((myViewHolder) holder).getTvTitle().setText(data[position].title);
         ((myViewHolder) holder).getTvContent().setText(data[position].content);
     }

     //获取RecycleView的长度
     @Override
     public int getItemCount() {
         return data.length;
     }
 }

MainActivity.java

 package com.liwenchi.learnrv;

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

 import java.util.ArrayList;
 public class MainActivity extends AppCompatActivity {

     private RecyclerView rv;

     private ArrayList<String> datas = new ArrayList<String>();

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);

         rv = new RecyclerView(this);

         createData(datas);

         setContentView(rv);

         rv.setLayoutManager(new LinearLayoutManager(this));

         rv.setAdapter(new MyAdapter());
     }

     public void createData(ArrayList<String> data) {

         for(char i='A';i<='Z';i++)
         {
             data.add(String.valueOf(i));
         }
     }
 }

CellData.java

 public class CellData {

     public CellData(String title, String content) {
         this.title = title;
         this.content = content;
     }

     String title = "title";
     String content = "Content";

 }

list_cell.xml

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:orientation="vertical"
     android:layout_width="match_parent"
     android:layout_height="match_parent">

     <TextView
         android:id="@+id/tvTitle"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:textAppearance="?android:attr/textAppearance"
         android:text="标题" />

     <TextView
         android:id="@+id/tvContent"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:text="内容" />
 </LinearLayout>