先获取文件列表存入Adapter,listview默认先显示一张小的图片,例如显示下在加载的小图片,并用Thread将当前ListView当前要显示的图片进行加载并缩小处理,处理后用Handler方式通过listView更新显示。
解决方案 »
- android 调用webservices时传泛型参数
- 求助大侠!!反复使用cursor后报错,我如何关闭cursor而在下一次启用cursor时又不受影响呢
- 按照Android高级编程写的ContactPicker不成功
- 如何调用当前BottomMain对象所在的Activity.finish()方法结束掉当前signListActivity?
- android 提取指定号码短信内容
- 连接多个设备时,adb会崩溃掉
- android如何用导航式采集数据呢??
- mediapalyer播放ogg文件的问题
- android中js调用java
- 只有.key文件,注意不是keystore文件,如何查看它的sha256等信息。
- 求教一个Gallery的问题:Gallery里的Item如何居右显示
- android SQLite 查询数据时总查不到,以前是可以的,求解啊!
import android.content.Context;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.provider.MediaStore;
import android.provider.MediaStore.Images;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;public class PictureActivity extends Activity{
private ListView picturefiles = null;
private Cursor cursor;
private ArrayList<PictureInfo> pictureList = new ArrayList<PictureActivity.PictureInfo>();
private static final String[] STORE_IMAGES = {
MediaStore.Images.Media.DATA,
MediaStore.Images.Media.MIME_TYPE,
MediaStore.Images.Media.DISPLAY_NAME,
MediaStore.Images.Media._ID
};
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.picture);
showimage();
// 单击显示图片
//picturefiles.setOnItemClickListener(new ShowItemImageOnClickListener());
}
public void showimage(){
picturefiles = (ListView)findViewById(R.id.picture_list);
cursor = this.managedQuery(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, STORE_IMAGES, null, null, null);
while(cursor.moveToNext()){
PictureInfo info = new PictureInfo();
info.filePath = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA));
info.mimeType = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.MIME_TYPE));
info.title = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DISPLAY_NAME));
//获取当前Picture对应的Id,然后根据该ID获取其Thumb
int id = cursor.getInt(cursor.getColumnIndexOrThrow(MediaStore.Images.Media._ID));
/*if(info.bitmap!=null&&!info.bitmap.isRecycled())
{
info.bitmap.recycle();
}*/
BitmapFactory.Options options=new BitmapFactory.Options();
options.inDither=false;
options.inPreferredConfig=Bitmap.Config.RGB_565;
info.bitmap=MediaStore.Images.Thumbnails.getThumbnail(getContentResolver(), id, Images.Thumbnails.MICRO_KIND, options);
//然后将其加入到pictureList
pictureList.add(info);
}
System.out.println(pictureList.size());
//然后需要设置ListView的Adapter了,使用我们自定义的Adatper
PictureAdapter adapter = new PictureAdapter(this);
picturefiles=(ListView)findViewById(R.id.picture_list);
picturefiles.setAdapter(adapter);
}
class PictureInfo{
String filePath;
String mimeType;
Bitmap bitmap;
String title;
}
class ViewHolder{
ImageView thumbImage;
TextView titleText;
}
/**
* 定义一个Adapter来显示缩略图和视频title信息
* @author Administrator
*
*/
private class PictureAdapter extends BaseAdapter{
private Context mContext;
private LayoutInflater inflater;
public PictureAdapter(Context context){
this.mContext = context;
this.inflater = LayoutInflater.from(context);
this.inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return pictureList.size();
}
@Override
public Object getItem(int p) {
// TODO Auto-generated method stub
return pictureList.get(p);
}
@Override
public long getItemId(int p) {
// TODO Auto-generated method stub
return p;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder ;
if(convertView == null){
holder = new ViewHolder();
convertView = inflater.inflate(R.layout.line, null);
holder.thumbImage = (ImageView)convertView.findViewById(R.id.icon);
holder.titleText = (TextView)convertView.findViewById(R.id.file_name);
convertView.setTag(holder);
}else{
holder = (ViewHolder)convertView.getTag();
}
//显示信息
holder.titleText.setText(pictureList.get(position).title);
if(pictureList.get(position).bitmap != null){
holder.thumbImage.setImageBitmap(pictureList.get(position).bitmap);
}
return convertView;
}
}
}