Android BaseAdapter 例子

BaseAdapter

 

public class RecentAdapter extends BaseAdapter {

	private class RecentViewHolder {
		TextView appName;
		ImageView appIcon;
		TextView appSize;
	}

	private List<ResolveInfo> mAppList;
	private LayoutInflater mInflater;
	private PackageManager pm;

	public RecentAdapter(Context c, List<ResolveInfo> appList,
			PackageManager pm) {
		mAppList = appList;
		this.pm = pm;
		mInflater = (LayoutInflater) c
				.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
	}
	
	public void clear(){
		if(mAppList!=null){
			mAppList.clear();
		}
	}

	public int getCount() {
		return mAppList.size();
	}

	@Override
	public Object getItem(int position) {
		return mAppList.get(position);
	}

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

	public View getView(int position, View convertView, ViewGroup parent) {
		RecentViewHolder holder;
		if (convertView == null) {
			convertView = mInflater.inflate(R.layout.app_info_item, null);
			holder = new RecentViewHolder();
			holder.appName = (TextView) convertView.findViewById(R.id.app_name);
			holder.appIcon = (ImageView) convertView
					.findViewById(R.id.app_icon);
			holder.appSize = (TextView) convertView.findViewById(R.id.app_size);
			convertView.setTag(holder);
		} else {
			holder = (RecentViewHolder) convertView.getTag();
		}
		ResolveInfo appInfo = mAppList.get(position);
		if (appInfo != null) {
			String labelName = appInfo.loadLabel(pm).toString();
			if (labelName != null) {
				holder.appName.setText(labelName);
			}

			Drawable icon = appInfo.loadIcon(pm);
			if (icon != null) {
				holder.appIcon.setImageDrawable(icon);
			}
		}
		return convertView;
	}
	
	public void remove(int position){
		mAppList.remove(position);
		this.notifyDataSetChanged();
	}

}

 

其中两个注意点为：

setTag 用View设置存储数据

notifyDataSetChanged() 告诉View数据更改并刷新

View convertView = mInflater.inflate(R.layout.app_info_item, null)  加载XML Item 示图

 

app_info_item.xml文件示例

 

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:layout_width="fill_parent" android:layout_height="wrap_content"
	android:layout_gravity="center_vertical" android:minHeight="?android:attr/listPreferredItemHeight">

	<ImageView android:id="@+id/app_icon" android:layout_width="@android:dimen/app_icon_size"
		android:layout_height="@android:dimen/app_icon_size"
		android:layout_alignParentLeft="true" android:paddingLeft="6dip"
		android:paddingTop="6dip" android:paddingBottom="6dip"
		android:scaleType="fitCenter" />

	<TextView android:id="@+id/app_name" android:layout_width="wrap_content"
		android:layout_height="wrap_content" android:textAppearance="?android:attr/textAppearanceLarge"
		android:textColor="?android:attr/textColorPrimary"
		android:layout_toRightOf="@id/app_icon" android:paddingLeft="6dip"
		android:paddingTop="6dip" />

	<TextView android:id="@+id/app_description"
		android:layout_width="wrap_content" android:layout_height="wrap_content"
		android:textAppearance="?android:attr/textAppearanceSmall"
		android:layout_below="@+id/app_name" android:layout_toRightOf="@id/app_icon"
		android:paddingLeft="6dip" android:paddingBottom="6dip" />
	<TextView android:id="@+id/app_size" android:layout_width="wrap_content"
		android:layout_height="wrap_content" android:textAppearance="?android:attr/textAppearanceSmall"
		android:layout_alignParentRight="true" android:layout_below="@+id/app_name"
		android:paddingRight="6dip" android:maxLines="1" />

</RelativeLayout>