如何在ImageView中使用URL引用的图像?
当前回答
这里有很多好的信息…我最近发现了一个叫SmartImageView的类,到目前为止它似乎工作得很好。非常容易合并和使用。
http://loopj.com/android-smart-image-view/
https://github.com/loopj/android-smart-image-view
更新:我最后写了一篇关于这个的博客文章,所以看看它对使用SmartImageView的帮助。
第二次更新:我现在总是用毕加索做这个(见上文),强烈推荐它。:)
其他回答
带有异常处理和异步任务的版本:
AsyncTask<URL, Void, Boolean> asyncTask = new AsyncTask<URL, Void, Boolean>() {
public Bitmap mIcon_val;
public IOException error;
@Override
protected Boolean doInBackground(URL... params) {
try {
mIcon_val = BitmapFactory.decodeStream(params[0].openConnection().getInputStream());
} catch (IOException e) {
this.error = e;
return false;
}
return true;
}
@Override
protected void onPostExecute(Boolean success) {
super.onPostExecute(success);
if (success) {
image.setImageBitmap(mIcon_val);
} else {
image.setImageBitmap(defaultImage);
}
}
};
try {
URL url = new URL(url);
asyncTask.execute(url);
} catch (MalformedURLException e) {
e.printStackTrace();
}
这将帮助你……
定义imageview并将图像加载到.....
Imageview i = (ImageView) vv.findViewById(R.id.img_country);
i.setImageBitmap(DownloadFullFromUrl(url));
然后定义这个方法:
public Bitmap DownloadFullFromUrl(String imageFullURL) {
Bitmap bm = null;
try {
URL url = new URL(imageFullURL);
URLConnection ucon = url.openConnection();
InputStream is = ucon.getInputStream();
BufferedInputStream bis = new BufferedInputStream(is);
ByteArrayBuffer baf = new ByteArrayBuffer(50);
int current = 0;
while ((current = bis.read()) != -1) {
baf.append((byte) current);
}
bm = BitmapFactory.decodeByteArray(baf.toByteArray(), 0,
baf.toByteArray().length);
} catch (IOException e) {
Log.d("ImageManager", "Error: " + e);
}
return bm;
}
要做到这一点,一个简单而干净的方法是使用开源库Prime。
适用于任何容器中的imageView,比如listview grid view, normal layout
private class LoadImagefromUrl extends AsyncTask< Object, Void, Bitmap > {
ImageView ivPreview = null;
@Override
protected Bitmap doInBackground( Object... params ) {
this.ivPreview = (ImageView) params[0];
String url = (String) params[1];
System.out.println(url);
return loadBitmap( url );
}
@Override
protected void onPostExecute( Bitmap result ) {
super.onPostExecute( result );
ivPreview.setImageBitmap( result );
}
}
public Bitmap loadBitmap( String url ) {
URL newurl = null;
Bitmap bitmap = null;
try {
newurl = new URL( url );
bitmap = BitmapFactory.decodeStream( newurl.openConnection( ).getInputStream( ) );
} catch ( MalformedURLException e ) {
e.printStackTrace( );
} catch ( IOException e ) {
e.printStackTrace( );
}
return bitmap;
}
/** Usage **/
new LoadImagefromUrl( ).execute( imageView, url );
你必须先下载图像
public static Bitmap loadBitmap(String url) {
Bitmap bitmap = null;
InputStream in = null;
BufferedOutputStream out = null;
try {
in = new BufferedInputStream(new URL(url).openStream(), IO_BUFFER_SIZE);
final ByteArrayOutputStream dataStream = new ByteArrayOutputStream();
out = new BufferedOutputStream(dataStream, IO_BUFFER_SIZE);
copy(in, out);
out.flush();
final byte[] data = dataStream.toByteArray();
BitmapFactory.Options options = new BitmapFactory.Options();
//options.inSampleSize = 1;
bitmap = BitmapFactory.decodeByteArray(data, 0, data.length,options);
} catch (IOException e) {
Log.e(TAG, "Could not load Bitmap from: " + url);
} finally {
closeStream(in);
closeStream(out);
}
return bitmap;
}
然后使用Imageview。setImageBitmap将位图设置为ImageView
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