我有一组按钮，我希望它们仅在加载图像时可见..并且要隐藏进度条，我该怎么做..无论何时使用 onPreExecute() 或编写
buttonname.setVisibility(View.VISIBLE);
在执行后它停止加载图像..这是我正在使用的..请帮帮我我被卡住了
public class Main extends Activity{
ImageView image,next,back;
Button a;
static int fullWidth;
static int fullHeight;
ProgressBar progressbar;
Button setWallpaper;
private class BackgroundTask extends AsyncTask <String, Void, Bitmap> {
protected Bitmap doInBackground(String...url) {
//--- download an image ---
Bitmap bitmap = DownloadImage(url[0]);
return bitmap;
}
protected void onPostExecute(Bitmap bitmap) {
ImageView image = (ImageView) findViewById(R.id.imageView1);
bitmaptwo=bitmap;
image.setImageBitmap(bitmap);
image.setScaleType(ScaleType.FIT_CENTER);
}
}
private InputStream OpenHttpConnection(String urlString)
throws IOException
{InputStream in = null;
int response= -1;
URL url = new URL(urlString);
URLConnection conn = url.openConnection();
if (!(conn instanceof HttpURLConnection ))
throw new IOException("Not an HTTP connection");
try{
HttpURLConnection httpConn = (HttpURLConnection) conn;
httpConn.setAllowUserInteraction(false);
httpConn.setInstanceFollowRedirects(true);
httpConn.setRequestMethod("GET");
httpConn.connect();
response = httpConn.getResponseCode();
if (response == HttpURLConnection.HTTP_OK){
in = httpConn.getInputStream();
}
}
catch (Exception ex)
{
throw new IOException("Error connecting");
}
return in;
}
private Bitmap DownloadImage(String URL)
{
Bitmap bitmap = null;
InputStream in = null;
try {
in = OpenHttpConnection(URL);
bitmap = BitmapFactory.decodeStream(in);
in.close();
}
catch (IOException e1){
Toast.makeText(this,e1.getLocalizedMessage(),
Toast.LENGTH_LONG).show();
e1.printStackTrace();
}
return bitmap;
}
public static Bitmap bitmaptwo;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_main);
try
{
new BackgroundTask().execute("http://meluha.in/wp-content/uploads/1.jpg");
}
catch(Exception e)
{
e.printStackTrace();
}
setWallpaper = (Button) findViewById(R.id.abcd);
ImageView next = (ImageView) findViewById(R.id.next);
ImageView back = (ImageView) findViewById(R.id.back);
setWallpaper.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
WallpaperManager wManager;
try {
// Bitmap bitmap = ((BitmapDrawable)imageView1.getDrawable()).getBitmap();
wManager = WallpaperManager.getInstance(getApplicationContext());
fullWidth = wManager.getDesiredMinimumWidth();
fullHeight = wManager.getDesiredMinimumHeight();
Bitmap bitmapResized = Bitmap.createScaledBitmap(bitmaptwo, fullWidth, fullHeight,true);
wManager.setBitmap(bitmapResized);
} catch (IOException e) {
e.printStackTrace();
}
}
});
}
}