四时宝库

ListView的基本用法

建博客这么久了，一直没能写点什么，其实一直想写来着，却又无从下手，今天终于下定决心写点什么，好吧，就ListView吧，这个控件是个搞基控件，所以初学者都会觉得很难，于是乎写了个demo，好吧转入正题！

分别是一个activity

一个实体类Mode

一个适配器adapter

public class MainActivity extends AppCompatActivity {

    private List<Mode> itemList =null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        final Context context = this;
        setContentView(R.layout.activity_main);
        ......
initdata; ListView listView = (ListView) findViewById(R.id.lv); myAdapter myAdapter = new myAdapter(this, itemList); listView.setAdapter(myAdapter); }
//绑定假数据 void initdata{ for (int i = 0; i < 20; i++) { Mode mode = new Mode; mode.setTitle("标题" + i); mode.setName("程序员" + i); itemList.add(mode); } }

 <ListView
 android:id="@+id/lv"
 android:layout_width="match_parent"
 android:layout_height="match_parent">
 </ListView>

这个布局文件决定了item的样式、结构。

<?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">

    <LinearLayout
        android:background="@color/colorAccent"
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="48dp">

        <TextView
 android:gravity="center"
 android:id="@+id/tv_title"
 android:layout_width="0dp"
 android:layout_weight="1"
 android:layout_height="match_parent"/>

        <TextView
 android:gravity="center"
 android:id="@+id/tv_name"
 android:layout_weight="1"
 android:layout_width="0dp"
 android:layout_height="match_parent"/>
    </LinearLayout>


</LinearLayout>

public class Mode implements Serializable{
private String title=null;
private String name=null;

public String getTitle{
return title;
}
public void setTitle(String Title){
title=Title;
}
public String getName{
return name;
}
public void setName(String Name){
name=Name;
}
}

• 接下来就是最重要的Adapter——myAdapter.class:

package com.example.administrator.listview;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import java.util.List;

/**
 * Created by Administrator on 2016/6/28.
 */
public class myAdapter extends BaseAdapter{

    private Context context;
    private List<Mode> modeList=null;

    public myAdapter(Context context,List<Mode> listList) {//activity中传递过来的上下文和list集合
        this.context=context;
        modeList=listList;
    }

    @Override
    public int getCount {//获取item的数目
        return modeList.size;
    }

    @Override
    public Object getItem(int position) {//获取item
        return modeList.get(position);
    }

    @Override
    public long getItemId(int position) {//item对应的id
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHodler viewHodler=null;
        if(null==convertView)
        {
 viewHodler=new ViewHodler;
 convertView=convertView.inflate(context,R.layout.list_item,null);
viewHodler.title=(TextView)convertView.findViewById(R.id.tv_title); viewHodler.name=(TextView)convertView.findViewById(R.id.tv_name);
convertView.setTag(viewHodler); }else{ viewHodler=(ViewHodler)convertView.getTag; } Mode mode=modeList.get(position); if (mode!=null){ viewHodler.title.setText(mode.getTitle); viewHodler.name.setText(mode.getName); } return convertView; } public class ViewHodler { TextView title; TextView name; } }

ListView大致基本结构就是如上所示，如果本文有不对的地方，还望指正。