【发布时间】：2016-04-11 11:46:56
【问题描述】：
我正在制作一个多视频下载器。我已经创建了一个列表视图，并且对于列表视图中的每个项目，都会调用一个异步任务，它会在后台下载文件。一切都很完美。但是，如果我想从列表视图中删除一个项目，例如从位置 2，位置 3 的项目（当前都在运行）出现在位置 2 上，之前附加到位置 2 的异步任务继续运行，它显示异步任务的进度之前附加到位置 2。如何将位置 3 的 asynctask 移动到位置 2。
这是我调用 asynctask 类的适配器类：
public class DownloadInfoArrayAdapter extends ArrayAdapter<DownloadInfo> {
public static TextView progpercent;
// Simple class to make it so that we don't have to call findViewById frequently
// private static final String TAG = FileDownloadTask.class.getSimpleName();
public static Integer result;
LayoutInflater inflater5;
ImageView delete;
Activity activity1;
int mvalue;
ContextWrapper cw1;
int flag=0;
int status=0;
GlobalDownload downloadList;
ArrayList downloadState;
FileDownloadTask task;
private static class ViewHolder {
TextView textView;
ProgressBar progressBar;
ImageView delete;
DownloadInfo info;
TextView size;
TextView prog;
public TextView progpercent;
}
private static final String TAG = DownloadInfoArrayAdapter.class.getSimpleName();
public DownloadInfoArrayAdapter(Context context, int textViewResourceId,
List<DownloadInfo> objects, ContextWrapper cw, Activity DownloadScreen) {
super(context, textViewResourceId, objects);
cw1=cw;
activity1=DownloadScreen;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
View row = convertView;
final DownloadInfo info = getItem(position);
ViewHolder holder = null;
if(null == row) {
LayoutInflater inflater = (LayoutInflater)getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
row = inflater.inflate(R.layout.file_download_row, parent, false);
holder = new ViewHolder();
holder.textView = (TextView) row.findViewById(R.id.downloadFileName);
holder.progressBar = (ProgressBar) row.findViewById(R.id.downloadProgressBar);
holder.size=(TextView) row.findViewById(R.id.downloadFileSize);
holder.progpercent=(TextView) row.findViewById(R.id.downloadFileProgress);
holder.delete=(ImageView) row.findViewById(R.id.deletebutton);
// holder.button = (Button)row.findViewById(R.id.downloadButton);
// holder.info = info;
row.setTag(holder);
} else {
holder = (ViewHolder) row.getTag();
}
holder.textView.setText(info.getFilename());
holder.progpercent.setText(info.getDownloadState().toString());
if(info.getStatus()== null)
{
Log.e("DATABASE1", "null ");
status=3;
info.setLastState(2);
}
else if(info.getStatus()== DownloadInfo.State.DONE)
{
if(info.getLastState()==1)
{
Log.e("DATABASE", "LS " + 1);
info.setDownloadState(DownloadInfo.DownloadState.COMPLETE);
status=1;
}
else if(info.getLastState()==0)
{
Log.e("DATABASE", "LS " + 2);
info.setDownloadState(DownloadInfo.DownloadState.FAILED);
status=1;
}
else
{
status=2;
}
}
Log.e("DATABASE", "DOWNLOAD STATE " + info.getDownloadState().toString());
if(info.getDownloadState()== DownloadInfo.DownloadState.NOT_STARTED)
{
if(status==3) {
holder.progressBar.setProgress(info.getProgress());
holder.progressBar.setMax(100);
holder.progpercent.setText("DOWNLOADING");
}
}
holder.size.setText(info.getFileSize());
info.setProgressBar(holder.progressBar);
if(info.getDownloadState()==DownloadInfo.DownloadState.NOT_STARTED){ info.setDownloadState(DownloadInfo.DownloadState.DOWNLOADING);
if (MainScreen.settingsvalue==0) {
Log.e("DATABASE", " " + 0);
mvalue = 0;
task = new FileDownloadTask(info, cw1, activity1, mvalue);
task.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
}
if(info.getDownloadState()== DownloadInfo.DownloadState.COMPLETE) {
Log.e("DATABASE", "UPDATE COMPLETE " + info.getDownloadState());
info.setStatus(DownloadInfo.State.DONE);
info.setLastState(1);
holder.progressBar.setProgress(R.drawable.download_bar);
holder.progpercent.setText(info.getDownloadState().toString());
cancelstatus=0;
}
if(info.getDownloadState()== DownloadInfo.DownloadState.FAILED) {
info.setStatus(DownloadInfo.State.DONE);
MainScreen.newDB.execSQL("update " + DatabaseHelper.TABLE_NAME + " set " + DatabaseHelper.COL_6 + " = '" + info.getStatus() + "', " + DatabaseHelper.COL_7 + " =0 where " + DatabaseHelper.COL_1 + " = " + info.getFileid());
Log.e("DATABASE", "UPDATED ");
info.setLastState(0);
holder.progpercent.setText(info.getDownloadState().toString());
cancelstatus=0;
}
holder.delete.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Integer index = (Integer) v.getTag();
Log.e("POSITION", "TAG " + index);
Log.e("POSITION", "POSITION " + position);
downloadList = ((GlobalDownload) activity1.getApplicationContext());
downloadState = (ArrayList) downloadList.getDownloadInfo();
CustomDialogClass.downloadfile=file.getAbsolutePath().toString();
CustomDialogClass2.customfilename2= info.getFilename() + "." + info.getFileType();
Log.e("VIDEOPATH", " " + CustomDialogClass.downloadfile);
CustomDialogClass2 cdd = new CustomDialogClass2(MainScreen.activity1);
cdd.show();
CustomDialogClass2.mPosition=position;
CustomDialogClass2.id=info.getFileid();
// downloadState.remove(position);
Log.e("STATUS", "Status before stopping " + info.getDownloadState());
if((info.getDownloadState()== DownloadInfo.DownloadState.DOWNLOADING)) {
info.setDownloadState(DownloadInfo.DownloadState.COMPLETE);
cancelstatus=1;
task.cancel(true);
}
}
});
return row;
}
}
这里是 Asynctask 类
public class FileDownloadTask extends AsyncTask<String, Integer, Integer> {
private static final String TAG = FileDownloadTask.class.getSimpleName();
final DownloadInfo mInfo;
TextView display;
public int progress;
public String encodedurl;
PopupWindow popupWindow;
Activity activity;
// ListView listview1;
// Context context;
LayoutInflater layoutInflater;
static int i=0;
int Mvalue;
ContextWrapper cw;
File file;
String nameoffile;
PowerManager mgr;
PowerManager.WakeLock wakeLock;
public static int cancelstatus =0;
int a=0;
// DownloadInfoArrayAdapter mAdapter;
public FileDownloadTask(DownloadInfo info, ContextWrapper cw1, Activity activity1, int mvalue) {
mInfo = info;
cw=cw1;
activity=activity1;
this.Mvalue=mvalue;
// listView1 = (ListView) listview.findViewById(R.id.downloadListView);
// mAdapter = new DownloadInfoArrayAdapter(, R.id.downloadListView,mInfo);
}
// @Override
protected void onProgressUpdate(Integer... values) {
mInfo.setProgress(values[0]);
mInfo.setFilePercent(values[0]);
// Log.e("FILE PERCENT", String.valueOf(mInfo.getFilePercent()));
// mAdapter.notifyDataSetChanged();
// mAdapter.setNotifyOnChange(true);
// display = (TextView) row.findViewById(R.id.downloadFileProgress);
ProgressBar bar = mInfo.getProgressBar();
// Integer percent=mInfo.getFilePercent();
if (bar != null) {
bar.setProgress(mInfo.getProgress());
// percent(mInfo.getFilePercent());
// display.setText(mInfo.getProgress());
// bar.invalidate();
}
// DownloadScreen.adapter.notifyDataSetChanged();
// DownloadScreen.listView.setAdapter(DownloadScreen.adapter);
}
@Override
protected void onCancelled() {
super.onCancelled();
mInfo.setDownloadState(DownloadInfo.DownloadState.COMPLETE);
File rootdirectory = new File(Environment.getExternalStorageDirectory(), "YoutubeDownloaderVideos");
File file = new File(rootdirectory, CustomDialogClass2.customfilename2);
Log.e("FILE", " name" + file.toString());
file.delete();
DownloadScreen.adapter.notifyDataSetChanged();
}
@Override
protected Integer doInBackground(String... params) {
int count;
try {
String state = Environment.getExternalStorageState();
String root = Environment.getExternalStorageDirectory().toString();
URL url = new URL(mInfo.getFileUrl().toString());
Log.e("URL", "" + url);
HttpURLConnection conection = (HttpURLConnection) url.openConnection();
conection.connect();
Log.e("connection", " " + 0);
int lenghtOfFile = conection.getContentLength();
Log.e("length", "" + lenghtOfFile);
String nameoffile = mInfo.getFilename() + "." + mInfo.getFileType();
if (Environment.MEDIA_MOUNTED.equals(state)) {
File rootdirectory = new File(Environment.getExternalStorageDirectory(), "YoutubeDownloaderVideos");
if (!rootdirectory.exists()) {
rootdirectory.mkdirs();
}
File file = new File(rootdirectory, nameoffile);
file.createNewFile();
Log.e("name of file", "" + nameoffile);
InputStream input = new BufferedInputStream(url.openStream(), 8192);
OutputStream output = new FileOutputStream(file);
byte data[] = new byte[1024];
mInfo.setDownloadState(DownloadInfo.DownloadState.DOWNLOADING);
long total = 0;
while ((count = input.read(data)) != -1) {
if(!isCancelled()) {
total += count;
progress = (int) ((total * 100) / lenghtOfFile);
publishProgress(progress);
// Log.e("PROGRESS", "" + mInfo.getFileType() + progress);
mInfo.setFilePercent(progress);
output.write(data, 0, count);
i = 1;
}
}
mInfo.setDownloadState(DownloadInfo.DownloadState.COMPLETE);
mInfo.setStatus(DownloadInfo.State.COMPLETE);
output.flush();
output.close();
input.close();
Log.e("Download Complete", "" + 0);
Log.e("DEVICE SDCARD", " " + Mvalue);
}
return progress;
}
protected void onPostExecute(Integer progress) {
mInfo.setDownloadState(DownloadInfo.DownloadState.COMPLETE);
DownloadScreen.adapter.notifyDataSetChanged();
DownloadScreen.listView.setAdapter(DownloadScreen.adapter);
Uri contentUri = Uri.fromFile(file);
Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE,contentUri);
activity.sendBroadcast(mediaScanIntent);
CustomDialogClass.downloadfile=file.getAbsolutePath().toString();
CustomDialogClass.customfilename=mInfo.getFilename() + "." + mInfo.getFileType();
Log.e("VIDEOPATH", " " + CustomDialogClass.downloadfile);
CustomDialogClass cdd = new CustomDialogClass(MainScreen.activity1);
cdd.show();
}
@Override
protected void onPreExecute() {
}
}
【问题讨论】：
标签： android listview android-asynctask