[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>