对BaseAdapter和ViewHolder的封装

项目结构如下:



其中MyBaseAdapter和BaseHolder是2个抽象类,分别是对BaseAdapter和ViewHolder的封装.MainActivity为测试类.

1.MyBaseAdapter类

package com.example.mchenys.mybaseadapterdemo.adapter;

import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;

import com.example.mchenys.mybaseadapterdemo.holder.BaseHolder;

import java.util.List;

/**
* 自定义BaseAdapter的基类
* Created by mChenys on 2015/11/15.
*/
public abstract class MyBaseAdapter<T> extends BaseAdapter {
private List<T> mData;

public MyBaseAdapter(List<T> data) {
mData = data;
}

@Override
public int getCount() {
return mData == null ? 0 : mData.size();
}

@Override
public T getItem(int position) {
return mData == null ? (T) null : mData.get(position);
}

@Override
public long getItemId(int position) {
return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
BaseHolder holder;
if (null == convertView) {
holder = getBaseHolder(position);
convertView = holder.getConvertView();
} else {
holder = (BaseHolder) convertView.getTag();
}
holder.setData(getItem(position));
return convertView;
}

/**
* 由子类去实现获取BaseHolder的方法
*
* @param position
* @return BaseHolder
*/
public abstract BaseHolder getBaseHolder(int position);
}

2.BaseHolder类

package com.example.mchenys.mybaseadapterdemo.holder;

import android.view.View;

/**
* 自定义BaseHolder的基类
* Created by mChenys on 2015/11/15.
*/
public abstract class BaseHolder<T> {
private View mRootView;
private T mData;

public BaseHolder() {
//初始化item的根布局
mRootView = initItemLayout();
//绑定holder到当前根布局中
mRootView.setTag(this);
}

/**
* 获取item的根布局
*
* @return
*/
public View getConvertView() {
return mRootView;
}

/**
* 设置item的数据
*
* @param t 具体的数据
*/
public void setData(T t) {
mData = t;
refreshView(t);
}

/**
* 获取显示的数据
*
* @return
*/
public T getmData() {
return mData;
}

/**
* 由子类去实现刷新界面数据的方法
*
* @param t 具体的数据
*/
public abstract void refreshView(T t);

/**
* 由具体的子类去实现初始化listView Item的根布局
*
* @return
*/
public abstract View initItemLayout();
}

3.MainActivity测试类

package com.example.mchenys.mybaseadapterdemo;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.ListView;
import android.widget.TextView;

import com.example.mchenys.mybaseadapterdemo.adapter.MyBaseAdapter;
import com.example.mchenys.mybaseadapterdemo.holder.BaseHolder;

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

public class MainActivity extends AppCompatActivity {

private List<String> mData = new ArrayList<>();
private ListView mListView;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mListView = new ListView(this);
setContentView(mListView);
initData();
showListView();
}

/**
* 显示ListView
*/
private void showListView() {
mListView.setAdapter(new MyBaseAdapter<String>(mData) {
@Override
public BaseHolder getBaseHolder(int position) {

return new BaseHolder<String>() {
private TextView tvInfo;

@Override
public View initItemLayout() {
View view = View.inflate(MainActivity.this, R.layout.item_list, null);
tvInfo = (TextView) view.findViewById(R.id.id_tv_info);
return view;
}

@Override
public void refreshView(String s) {
tvInfo.setText(s);
}
};
}
});
}

/**
* 初始化测试数据
*/
private void initData() {
for (int i = 0; i < 20; i++) {
mData.add("测试数据:" + i);
}
}
}

4.item_list.xml文件

<?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"
android:orientation="vertical">

<TextView
android:id="@+id/id_tv_info"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:padding="10dp" />
</LinearLayout>

5.测试效果