自定义适配器

什么是适配器设计模式
        将一个类的接口变换成客户端所期待的一种接口，从而使原本因接口不匹配而无法在一起工作的两个类能够在一起工作。
    


    BaseAdapter
             Adapter接口的实现类
    包含四个抽象方法：
         int getCount()
 View getView(int position,....)
 Object getItem(int position)
 Long getItemId(int position)
 自定义Adapter案例
         实现步骤
      定义布局文件
      准备数据集
      创建自定义适配器

      初始化ListView

小案例：

       布局：

<ListView 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"
    android:id="@+id/lvStudent"
 />

item.xml布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal"
     xmlns:android="http://schemas.android.com/apk/res/android"
     >
    <ImageView 
        android:layout_width="64dp"
        android:layout_height="64dp"
        android:src="@drawable/image"/>
    <TableLayout 
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="1.0"
        android:stretchColumns="*">
        <TableRow 
            android:layout_height="0dp"
            android:layout_weight="1.0">
            <TextView 
                android:id="@+id/tvId"
                android:layout_height="match_parent"
                android:gravity="center_vertical"
                android:textSize="20sp"/>
            <TextView
                android:id="@+id/tvName"
                android:layout_height="match_parent"
                android:gravity="center_vertical"
                android:textSize="20sp"
                />
        </TableRow>
        <TableRow 
            android:layout_height="0dp"
            android:layout_weight="1.0">
            <TextView 
                android:id="@+id/tvSex"
                android:layout_height="match_parent"
                android:gravity="center_vertical"
                android:textSize="20sp"/>
            <TextView 
                android:id="@+id/tvAge"
                android:layout_height="match_parent"
                android:gravity="center_vertical"
                android:textSize="20sp"/>
        </TableRow>
    </TableLayout>
</LinearLayout>

适配器：

     

package com.example.listview;

import java.util.ArrayList;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.webkit.WebView.FindListener;
import android.widget.BaseAdapter;
import android.widget.TextView;

public class StudentAdapter extends BaseAdapter {

	private ArrayList<Student> stus;
	private LayoutInflater inflater;
	
	public StudentAdapter(Context context,ArrayList<Student> stus){
		if(stus != null)
			this.stus = stus;
		else
			this.stus = new ArrayList<Student>();
		this.inflater = LayoutInflater.from(context);
	}
	@Override
	public int getCount() {
		// TODO Auto-generated method stub
		return stus.size();
	}

	@Override
	public Object getItem(int position) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public long getItemId(int position) {
		// TODO Auto-generated method stub
		return 0;
	}

	@Override
	public View getView(int position, View convertView, ViewGroup parent) {
		// TODO Auto-generated method stub
		
		View v = inflater.inflate(R.layout.item, null);
		TextView tvId = (TextView)v.findViewById(R.id.tvId);
		TextView tvName = (TextView)v.findViewById(R.id.tvName);
		TextView tvSex = (TextView)v.findViewById(R.id.tvSex);
		TextView tvAge = (TextView)v.findViewById(R.id.tvAge);
		
		Student stu = stus.get(position);
		
		tvId.setText(""+stu.getId());
		tvName.setText(stu.getName());
		tvSex.setText(stu.getSex());
		tvAge.setText("" + stu.getAge());
		return v;
	}

}

学生类：

   

package com.example.listview;

public class Student {
      private int id;
      private String name;
      private String sex;
      private int age;
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getSex() {
		return sex;
	}
	public void setSex(String sex) {
		this.sex = sex;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
     public Student(int id,String name,String sex,int age){
    	 super();
    	 this.id=id;
    	 this.name=name;
    	 this.sex=sex;
    	 this.age=age;
     }
     public Student(){
    	 super();
     }
}

用来返回所有的信息：

package com.example.listview;

import java.util.ArrayList;

public class StudentBiz {
     public static ArrayList<Student> getStudents(){
    	 ArrayList<Student> stus = new ArrayList<>();
        for(int i=1; i <=10; i++){
        	Student stu = new Student(i, "同学"+ i,"男",23);
          stus.add(stu);
        }
        return stus;
     }
}

主Activity：

package com.example.listview;


import android.app.Activity;
import android.os.Bundle;
import android.widget.ListView;

public class MainActivity extends Activity {
  
	private ListView lvStus;
	private StudentAdapter adapter;
	
   
   private void setupView(){
	  lvStus = (ListView) findViewById(R.id.lvStudent);
	  adapter = new StudentAdapter(this,StudentBiz.getStudents());
	  lvStus.setAdapter(adapter);
   }
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		setupView();
	}
}