我的ListView由一些音乐组成，每个项目旁边都有一个图标，如果音乐存在于 SD 卡中，则图标为播放图标，否则为下载图标。
当我单击下载图标时，它会以 a 开始下载，ProgressBar但如果我在下载时按后退按钮，然后再次返回活动，则进度条消失并且播放图标可见。
回到活动时，如何从上次更改中更新？
活动音乐：
ActivityMusic.myFileDownloadTask task = new ActivityMusic.myFileDownloadTask(info, mAdapter, myList);
task.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
我的适配器：
ActivityMusic.myFileDownloadTask task = new ActivityMusic.myFileDownloadTask(info, mAdapter, myList);
task.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
我的文件下载任务：
public static class myFileDownloadTask extends AsyncTask<String, Integer, String> {
// private static final String TAG = FileDownloadTask.class.getSimpleName();
final DownloadInfo mInfo;
public List<DownloadInfo> myList;
private String url = "";
// public DownloadInfoArrayAdapter downloadInfoArrayAdapter;
public myFileDownloadTask(DownloadInfo info, DownloadInfoArrayAdapter mAdapter, List<DownloadInfo> updateList) {
mInfo = info;
info.setDownloading(true);
mInfo.setDownloading(true);
mInfo.setDownloadState(DownloadInfo.DownloadState.DOWNLOADING);
// downloadInfoArrayAdapter = mAdapter;
myList = updateList;
}
//
@Override
protected void onProgressUpdate(Integer... values) {
mInfo.setProgress(values[0]);
ProgressBar bar = mInfo.getProgressBar();
if (bar != null) {
ActivityMusic.loading.setVisibility(View.INVISIBLE);
bar.setProgress(mInfo.getProgress());
bar.invalidate();
}
}
@Override
protected void onPostExecute(String result) {
mInfo.setDownloadState(DownloadInfo.DownloadState.COMPLETE);
ProgressBar progressBar = mInfo.getProgressBar();
progressBar.setVisibility(View.INVISIBLE);
mInfo.setDownloading(false);
ImageView img = mInfo.getDImageView();
img.setImageResource(R.drawable.download);
mInfo.setDImaegView(img);
mInfo.getDImageView().setVisibility(View.INVISIBLE);
mInfo.setProgressBar(progressBar);
ImageView img2 = mInfo.getImageView();
img2.setImageResource(R.drawable.play);
mInfo.setPImaegView(img2);
mInfo.getImageView().setEnabled(true);
mInfo.getImageView().setVisibility(View.VISIBLE);
mInfo.getImageView().setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// Toast.makeText(ActivityMusic.mcontext, "Ari", Toast.LENGTH_SHORT).show();
File mfolder = new File(Environment.getExternalStorageDirectory() + "/Sh_M/" + mInfo.getFilename() + ".mp3");
DownloadInfoArrayAdapter.mUri = Uri.fromFile(mfolder);
ActivityMusic.audioWife.getInstance().release();
ActivityMusic.audioWife
.init(null, DownloadInfoArrayAdapter.mUri)
.setPlayView(ActivityMusic.mPlayMedia)
.setPauseView(ActivityMusic.mPauseMedia)
.setSeekBar(ActivityMusic.mMediaSeekBar)
.setRuntimeView(ActivityMusic.mRunTime)
.setTotalTimeView(ActivityMusic.mTotalTime).play();
ActivityMusic.relativeLayout.setVisibility(View.VISIBLE);
ActivityMusic.isPlaying = true;
}
});
// downloadInfo.add(new DownloadInfo("", 1000, ""));
// myList.add(ActivityMusic.downloadInfo.get(0));
// downloadInfoArrayAdapter = new DownloadInfoArrayAdapter(mcontext,R.id.list_view,downloadInfo);
// listView.setAdapter(downloadInfoArrayAdapter);
downloadInfoArrayAdapter.notifyDataSetChanged();
// ActivityMusic.downloadInfoArrayAdapter.notifyDataSetChanged();
}
@Override
protected void onPreExecute() {
mInfo.setDownloadState(DownloadInfo.DownloadState.DOWNLOADING);
mInfo.setDownloading(true);
}
@Override
protected String doInBackground(String... f_url) {
// mInfo.setDownloadState(DownloadInfo.DownloadState.DOWNLOADING);
int count;
try {
URL url = new URL(mInfo.getLink());
URLConnection conection = url.openConnection();
conection.connect();
// getting file length
int lenghtOfFile = conection.getContentLength();
// input stream to read file - with 8k buffer
InputStream input = new BufferedInputStream(url.openStream(), 8192);
File folder = new File(Environment.getExternalStorageDirectory() + "/Sh_M");
if (!folder.exists()) {
folder.mkdir();
}
// Output stream to write file
OutputStream output = new FileOutputStream("/sdcard/Sh_M/" + mInfo.getFilename() + ".mp3");
byte data[] = new byte[1024];
long total = 0;
while ((count = input.read(data)) != -1) {
total += count;
// publishing the progress....
// After this onProgressUpdate will be called
publishProgress((int) ((total * 1000) / lenghtOfFile));
// writing data to file
output.write(data, 0, count);
}
// flushing output
output.flush();
// closing streams
output.close();
input.close();
} catch (Exception e) {
Log.e("Error: ", "");
}
return null;
}
}