我有一个从互联网加载图像的图像视图。我正在从网络加载图像并使用异步任务将其转换为位图图像。我想在我的图像视图中显示一个静态图像,并在图像加载时在图像视图顶部有一个进度微调器。问题是我的 xml 中有进度微调器,我无法在异步任务中使用它,而且我不知道如何使进度微调器在图像视图中也可见。我该怎么做呢?这是我的异步任务类:
public class LoadImage extends AsyncTask<Void, Void, Bitmap>{
Context callingContext = null;
ImageView view;
String b = null;
ListView lv;
ProgressDialog p;
public LoadImage(Context c, ImageView view, String b){
this.view = view;
this.b = b;
this.callingContext = c;
}
@Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
// p = (ProgressDialog) findViewById(R.id.progressBar1);
p = ProgressDialog.show(callingContext, "Loading Events", "Retrieving data from server, please wait...", true);
}
public Bitmap getBit(String data){
Bitmap bitmap;
BitmapFactory.Options bmOptions;
bmOptions = new BitmapFactory.Options();
bmOptions.inJustDecodeBounds = true;
//from web
try {
bitmap=null;
InputStream is=new URL(data).openStream();
BitmapFactory.decodeStream(is, null, bmOptions);
is.close();
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = 20;
is = new URL(data).openStream();
bitmap = BitmapFactory.decodeStream(is, null, o2);
is.close();
return bitmap;
} catch (Exception ex){
ex.printStackTrace();
return null;
}
}
@Override
protected Bitmap doInBackground(String... arg0) {
// TODO Auto-generated method stub
Bitmap b = null;
URL imageUrl = null;
b = getBit(this.b);
return b;
}
@Override
protected void onPostExecute(Bitmap result) {
// TODO Auto-generated method stub
super.onPostExecute(result);
if(result == null)
view.setImageResource(R.drawable.ic_launcher);
p.dismiss();
}
}