原文地址:http://blog.csdn.net/shakespeare001/article/details/7926783
收藏ArrayAdapter、SimpleAdapter和BaseAdapter的一些簡短代碼片段,希望用時方便想起其用法。
1.ArrayAdapter
只可以簡單的顯示一行文本
代碼片段:
ArrayAdapter<String> adapter = new ArrayAdapter<String>(
this,
R.layout.item,//只能有一個定義了id的TextView
data);//data既可以是數組,也可以是List集合
2.SimpleAdapter
可以顯示比較複雜的列表,包括每行顯示圖片、文字等,但不能對列表進行後期加工(在java代碼中加工),
也是隻是單純的負責顯示(當然可以設計複雜點的佈局來顯示覆雜列表),例如,每行顯示不同背景等。
代碼片段:
List<Map<String,Object>> mData= new ArrayList<Map<String,Object>>();;
for(int i =0; i < lengh; i++) {
Map<String,Object> item = new HashMap<String,Object>();
item.put("image", R.drawable.portrait);
item.put("title", mListTitle[i]);
item.put("text", mListStr[i]);
mData.add(item);
}
SimpleAdapter adapter = new SimpleAdapter(
this,
mData,
R.layout.item,
new String[]{"image","title","text"},
new int[]{R.id.image,R.id.title,R.id.text});
3.BaseAdapter
可以實現複雜的列表佈局,由於BaseAdapter是一個抽象類,使用該類需要自己寫一個適配器繼承該類,
正是由於繼承了該類,需要我們重寫一些方法,讓我們可以在代碼裏控制列表的樣式,更加靈活。
代碼片段:
private class MyListAdapter extends BaseAdapter{
private Context mContext;
private int[] colors=new int[]{0xff626569,0xff4f5257 };
public MyListAdapter(Context context){
mContext=context;
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return mListText.length;
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ImageView image=null; //這些控件可以單獨封裝成一個類(Holder),便與優化
TextView title=null;
TextView content=null;
if(convertView==null){
convertView=LayoutInflater.from(mContext).inflate(R.layout.colorlist, null);
image=(ImageView) convertView.findViewById(R.id.color_image);
title=(TextView) convertView.findViewById(R.id.color_title);
content=(TextView) convertView.findViewById(R.id.color_text);
}
int colorPos=position%colors.length;
convertView.setBackgroundColor(colors[colorPos]);
title.setText(mListTitle[position]);
content.setText(mListText[position]);
image.setImageResource(R.drawable.portrait);
return convertView;
}
}
--------------------------下面樣例列表頁的控件單獨封裝成了一個類(Holder),便與優化-----
public class MyBaseAdapter extends BaseAdapter{
private LayoutInflater mInflater;
public MyAdapter(Context context){
this.mInflater = LayoutInflater.from(context);
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return mData.size();
}
@Override
public Object getItem(int arg0) {
// TODO Auto-generated method stub
return null;
}
@Override
public long getItemId(int arg0) {
// TODO Auto-generated method stub
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
if (convertView == null) {
holder=new ViewHolder();
convertView = mInflater.inflate(R.layout.vlist2, null);
holder.img = (ImageView)convertView.findViewById(R.id.img);
holder.title = (TextView)convertView.findViewById(R.id.title);
holder.info = (TextView)convertView.findViewById(R.id.info);
holder.viewBtn = (Button)convertView.findViewById(R.id.view_btn);
convertView.setTag(holder);
}else {
holder = (ViewHolder)convertView.getTag();
}
holder.img.setBackgroundResource((Integer)mData.get(position).get("img"));
holder.title.setText((String)mData.get(position).get("title"));
holder.info.setText((String)mData.get(position).get("info"));
//給每一個列表後面的按鈕添加響應事件
holder.viewBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
showInfo();
}
});
return convertView;
}
------------
public final class ViewHolder{
public ImageView img;
public TextView title;
public TextView info;
public Button viewBtn;
}