Android Adapter的简单封装

HolderAdapter背景

Android的AdapterView用的比较多，ListView，GridView，Spinner等，原生的BaseAdapter对ViewHolder没有支持，每次都要，定义内部类，inflater根布局，对item内部view设置clicklistener并转发到adapter的调用者等。写的次数多了感觉很繁琐，于是写了个简单的封装，简化Adapter的编写，仓库连接http://git.oschina.net/phodev/SimpleAdapter.

主要文件介绍

1，CommonAdapter.java从BaseAdapter继承，添加了常用的函数，通过泛型约定了List数据源，代替子类实现getCount功能,添加bindClick实现Adapter的OnItemClickListener。

2，BaseViewHolder.java和HolderAdapter结合，实现类似Activity的view初始化方方式onCreate->setContentView->findViewById。

3，HolderAdapter.java从CommonAdapter继承，主要用来驱动BaseViewHolder工作。

使用方法

1,Adapter定义

public class SampleHolderAdapter extends HolderAdapter<Object> {
//定义Item内部的点击事件，如果不需要可以不定义
public static final int CLICK_ACTION_ADD = 1;
public static final int CLICK_ACTION_UPDATE = 2;
public static final int CLICK_ACTION_DELETE = 3;
//构造函数配置数据源（可选，或者之后通过setData更新）
public SampleHolderAdapter(List<Object> data) {
super(data);
}

@Override
public BaseViewHolder<?> createViewHolder(int position) {
//创建期望的 ViewHolder
return new ViewHolder();
}

class ViewHolder extends
4000
BaseViewHolder<Object> {
Button btn1, btn2, btn3;

@Override
protected void onCreate(Context context, ViewGroup parent) {
//ViewHolder创建后onCreate会被执行1次
setContentView(R.layout.item_test);//setContent支持View或者layout id
btn1 = (Button) findViewById(R.id.btn1);//findViewById
btn2 = (Button) findViewById(R.id.btn2);
btn3 = (Button) findViewById(R.id.btn3);
}

@Override
protected void onDataChanged(int position, Object data) {
//adapter getView的时候onDataChanged会被执行一次
btn1.setText("add " + position);
btn2.setText("update " + position);
btn3.setText("delete " + position);
//
bindClick(btn1, position, CLICK_ACTION_ADD);//绑定ItemClick，每次都需bind
bindClick(btn2, position, CLICK_ACTION_UPDATE);
bindClick(btn3, position, CLICK_ACTION_DELETE);
}
}

}

2,Adapter使用

//数据源
private final ArrayList<Object> mData = new ArrayList<>();
//创建Adapter并绑定数据源
private final SampleHolderAdapter mAdapter = new SampleHolderAdapter(mData);

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mListView = (ListView) findViewById(R.id.listview);
//绑定Adapter
mListView.setAdapter(mAdapter);
//设置click listener（由于CommonAdapter支持，并通过bindClick声明）
mAdapter.setOnItemClickListener(onItemClickListener);
}

//ClickListener实现
private OnItemClickListener onItemClickListener = new OnItemClickListener() {
@Override
public void onItemClick(CommonAdapter<?> adapter, View v, int position, int action) {
switch (action) {//action就是我们SampleHolderAdapte中定义并且bindClick的value
case SampleHolderAdapter.CLICK_ACTION_ADD:
toast(getContext(), position + " add click");
break;
case SampleHolderAdapter.CLICK_ACTION_UPDATE:
toast(getContext(),position + " update click");
break;
case SampleHolderAdapter.CLICK_ACTION_DELETE:
toast(getContext(), position + " delete click");
break;
}
}
};

到此定义和使用的代码完毕。