使用的AsyncTask的RecyclerView下载图片在安卓 [英] Downloading Image in android using asynctask for RecyclerView
本文介绍了使用的AsyncTask的RecyclerView下载图片在安卓的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
这我下面的AsyncTask
类code下载图像 RecyclerView
。
This my following AsyncTask
class code for downloading image for RecyclerView
.
public class MyDownloadImageAsyncTask extends AsyncTask<String, Void,Bitmap> {
private final WeakReference<ImageView> imageViewReference;
public MyDownloadImageAsyncTask(ImageView imv) {
imageViewReference = new WeakReference<ImageView>(imv);
}
@Override
protected Bitmap doInBackground(String... urls) {
Bitmap bitmap = null;
for (String url : urls) {
bitmap = MyUtility.downloadImage(url);
/*if (bitmap != null) {
mImgMemoryCache.put(url, bitmap);
}*/
}
return bitmap;
}
protected void onPostExecute(Bitmap bitmap){
if (imageViewReference != null && bitmap != null) {
final ImageView imageView = imageViewReference.get();
if (imageView != null) {
imageView.setImageBitmap(bitmap);
}
}
}
}
我称之为的AsyncTask
在我的适配器
是这样的:
MyDownloadImageAsyncTask task = new MyDownloadImageAsyncTask(holder.vIcon);
task.execute(new String[] {(String)movie.get("image")}););
该应用程序崩溃我每次运行它。该网址下载图像是一个的ArrayList
。
我想这个错误,我做这在调用的AsyncTask
,但我无法找出解决方案。
I guess the mistake I'm doing this in calling the AsyncTask
but I couldn't figure out the solution.
推荐答案
更改此
public MyDownloadImageAsyncTask(ImageView imv) {
imageViewReference = new WeakReference(imv);
}
本
public MyDownloadImageAsyncTask(ImageView imv) {
imageViewReference = new WeakReference<ImageView>(imv);
}
下面是我用code和它完美的作品
Here is the code that i use and it works perfect
class LoadImage extends AsyncTask<String, Void, Bitmap> {
private final WeakReference<ImageView> imageViewReference;
public LoadImage(ImageView imageView) {
imageViewReference = new WeakReference<ImageView>(imageView);
}
@Override
protected Bitmap doInBackground(String... params) {
try {
return downloadBitmap(params[0]);
} catch (Exception e) {
// log error
}
return null;
}
@Override
protected void onPostExecute(Bitmap bitmap) {
if (isCancelled()) {
bitmap = null;
}
if (imageViewReference != null) {
ImageView imageView = imageViewReference.get();
if (imageView != null) {
if (bitmap != null) {
imageView.setImageBitmap(bitmap);
} else {
Drawable placeholder = imageView.getContext().getResources().getDrawable(R.drawable.ic_launcher);
imageView.setImageDrawable(placeholder);
}
}
}
}
private Bitmap downloadBitmap(String url) {
HttpURLConnection urlConnection = null;
try {
URL uri = new URL(url);
urlConnection = (HttpURLConnection) uri.openConnection();
int statusCode = urlConnection.getResponseCode();
if (statusCode != HttpStatus.SC_OK) {
return null;
}
InputStream inputStream = urlConnection.getInputStream();
if (inputStream != null) {
Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
return bitmap;
}
} catch (Exception e) {
urlConnection.disconnect();
Log.w("ImageDownloader", "Error downloading image from " + url);
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
}
return null;
}
}
这里是我如何从称它为我的适配器
And here is how i call it from my ADAPTER
new LoadImage(holder.itemImage).execute(IMAGE_URL);
单独为每个URL。
seperately for every URL.
试试这个,如果它可以帮助你。
Try this if it helps you out.
这篇关于使用的AsyncTask的RecyclerView下载图片在安卓的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文