我有以下功能下载图片：
private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
private ImageButton bmImage;
public DownloadImageTask(ImageButton bmImage) {
this.bmImage = bmImage;
}
protected void onPreExecute() {
Log.wtf("IMAGETASK","onPREexecute");
//mDialog = ProgressDialog.show(ChartActivity.this,"Please wait...", "Retrieving data ...", true);
}
protected Bitmap doInBackground(String... urls) {
Bitmap bitmap = null;
String error_message = null;
for(String url:urls){
HttpUriRequest request = new HttpGet(url.toString());
HttpClient httpClient = new DefaultHttpClient();
try {
HttpResponse response = httpClient.execute(request);
StatusLine statusLine = response.getStatusLine();
int statusCode = statusLine.getStatusCode();
if (statusCode == 200) {
HttpEntity entity = response.getEntity();
byte[] bytes = EntityUtils.toByteArray(entity);
Log.e("here",""+bytes.length);
bitmap = BitmapFactory.decodeByteArray(bytes, 0,bytes.length);
Thread.sleep(1000);
}
else
{
error_message="Download failed, HTTP response code "+ statusCode + " - " + statusLine.getReasonPhrase();
}
} catch (Exception er) {
Log.e("Error",""+er);
}}
//image.setImageBitmap(bitmap);
return bitmap ;
}
/* OLD ONE (DOESN'T ALSO WORK)
protected Bitmap doInBackground(String... urls) {
String urldisplay = urls[0];
Bitmap mIcon11 = null;
try {
InputStream in = new java.net.URL(urldisplay).openStream();
mIcon11 = BitmapFactory.decodeStream(in);
} catch (Exception e) {
Log.wtf("Error", "image download error");
Log.wtf("Error", e.getMessage());
e.printStackTrace();
}
return mIcon11;
}*/
protected void onPostExecute(Bitmap result) {
Log.wtf("IMAGETASK","onPOSTexecute");
Log.wtf("IMAGETASK, POST EXECUTE",result.toString());
//set image of your imageview
bmImage.setImageBitmap(result);
android.view.ViewGroup.LayoutParams params = bmImage.getLayoutParams();
params.height = 50;
params.width = 50;
bmImage.setLayoutParams(params);
int width = bmImage.getWidth();
int height = bmImage.getHeight();
Log.wtf("width",String.valueOf(width));
Log.wtf("height",String.valueOf(height));
layout.addView(bmImage); //APPENDING ELEMENT (WITH IMAGE)
}
}
以及以下代码创建元素：
private void buildElement(final String friend_id, final String user_id, String name){
ImageButton element = (ImageButton) getLayoutInflater().inflate(R.layout.ELEMENT_LAYOUT, something, false);
String img_value = "VALID IMAGE LINK"
element.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
focus();
}
});
new DownloadImageTask(element).execute(img_value);
}
这是 ELEMENT_LAYOUT.xml ：
<ImageButton
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
style="?android:attr/buttonStyleSmall"
android:text="New Button"
android:layout_width="30dp"
android:layout_height="30dp"
android:scaleType="fitXY"
android:layout_alignParentTop="true"/>
ImageButton的创建确实但是它只是一个很小的灰色方块。有什么想法吗？此外，Log.wtf("width",String.valueOf(width)); Log.wtf("height",String.valueOf(height));记录了＆＃39; 0＆＃39;，＆＃39; 0＆＃39;。非常感谢你......