在开发中我们需要绑定一些数据展现到桌面上,这是就需要AdapterView。AdapterView是ViewGroup的子类,它决定了怎么展现视图通过Adapter来绑定特殊的数据类型。 AdapterView是非常有帮助的当你展现数据在你的布局中。Gallery
,ListView
和 Spinner是AdapterView的子类。
下面看一下AdapterView的结构图:
然后再看一下Adapter的结构图:
上面已经充分展现了他们的子类和父类的基础关系。
下面我们看一个ListViewDemo的例子:
先来看一个简单的adapter的例子:
public class SimpleList extends ListActivity {
private String[] mListString={"姓名:王魁锋","性别:男","年龄:23",
"居住地:上海市普陀区","邮箱:[email protected]"};
private ListView mListView=null;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
mListView=this.getListView();
setListAdapter(new ArrayAdapter(this,
android.R.layout.simple_list_item_1,mListString));
mListView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView parent, View view,
int position, long id) {
// TODO Auto-generated method stub
Toast.makeText(SimpleList.this, "你选择了:"+mListString[position], 1).show();
}
});
}
接下来看一个稍微复杂点的,SimpleAdapter怎么适配:
public class IconList extends ListActivity {
private String[] mListTitle = { "姓名", "性别", "年龄", "居住地","邮箱"};
private String[] mListStr = { "王魁锋", "男", "23", "上海市普陀区",
"[email protected]"};
ListView mListView = null;
ArrayList
上面的数据可以是同数据库读取的也可以是从网络获取的,这里不做过多介绍,看下效果:
哈哈 看起来美观了些,如果要做更复杂的布局,哪就要用BaseAdapter了。先看一下布局文件:
public class ColorList extends ListActivity {
private String[] mListTitle = { "姓名", "性别", "年龄", "居住地","邮箱"};
private String[] mListText={"王魁锋","男","23","上海市普陀区","[email protected]"};
private ListView mListView=null;
private MyListAdapter myAdapter=null;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
mListView=this.getListView();
myAdapter=new MyListAdapter(this);
this.setListAdapter(myAdapter);
mListView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView parent, View view,
int position, long id) {
// TODO Auto-generated method stub
View v=parent.getChildAt(position);
v.setBackgroundColor(Color.RED);
Toast.makeText(ColorList.this, "你选择了 "+mListText[position], 1).show();
}
});
super.onCreate(savedInstanceState);
}
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;
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;
}
}
}
BaseAdapter可以让我们做比较复杂的布局,只要在xml文件中设置好布局格式,在getView中分别取出放入相应的值就可以了。下面看一些效果:
还有一些SpinnerAdapter和SimpleCursorAdapter等系统自带的适配器,都是比较简单的,可以看下API自行练习一下,这里特别说明一下,从数据库里取出的数据最好直接放入 SimpleCursorAdapter很方便的。