私は現在、バックグラウンドでAsyncTaskを実行し、プログレスバーでUIを更新するアプリに取り組んでいます。プログレスバーはアプリの実行中は正常に機能しますが、ユーザーがアプリを終了して再入力すると、AsyncTaskはバックグラウンドで実行されたままになりますが、プログレスバーは更新されません。これは、AsyncTaskがアクティビティから切り離されたかのようです。AsyncTasksに関連する一般的なルールなど、これを引き起こしている可能性のあるアイデアを誰かが持っていますか？必要に応じてコードを提供することもできますが、かなり長いので、どの部分を見る必要があるか教えてください。また、AsyncTaskが完了することにも注意する必要があります。これは、終了時にデータベースをサーバーにアップロードするためです。
コードは次のとおりです。
public class BackgroundAsyncTask extends AsyncTask {int myProgress;
@Override
protected void onPostExecute(Void result) {
((TextView) findViewById(R.id.tv1)).setText("");
Cursor cur = sql3.query("videohashes", null, null, null, null,
null, null);
cur.moveToFirst();
while (!cur.isAfterLast()) {
Cursor curFrame = sql3.query("table_" + cur.getString(2), null,
null, null, null, null, null);
curFrame.moveToFirst();
((TextView) findViewById(R.id.tv1)).append("\nPath: "
+ cur.getString(1) + "\nHash: " + cur.getString(2)
+ "\nDate:" + cur.getString(3) + "\nSize: "
+ cur.getString(4) + " bytes\nResolution"
+ cur.getString(5) + "\nFormat: " + cur.getString(6)
+ "\nCodec: " + cur.getString(7) + "\nFPS: "
+ cur.getString(8) + "\n\nFirst Frame Info:\nType: "
+ curFrame.getString(1) + "\ncp_num: "
+ curFrame.getString(2) + "\ndp_num: "
+ curFrame.getString(3) + "\npts: "
+ curFrame.getString(4) + "\nqstride: "
+ curFrame.getString(5) + "\nsize: "
+ curFrame.getString(6) + "\nqp_stddev: "
+ curFrame.getString(7) + "\ncount: "
+ curFrame.getString(8) + "\nqp_avg: "
+ curFrame.getString(9) + "\n\n");
cur.moveToNext();
}
cur.close();
((Button) findViewById(R.id.btnSend)).setEnabled(true);
((Button) findViewById(R.id.btnStart)).setEnabled(true);
sql3.close();
sharedPreferences.edit().putString("lastVideoInfo", ((TextView) findViewById(R.id.tv1)).getText().toString()).commit();
sharedPreferences.edit().putBoolean("asyncTaskRunning", false).commit();
dateNow = new Date();
super.onPostExecute(result);
}
@Override
protected void onPreExecute() {
super.onPreExecute();
totProgress = 0;
currVid = 0;
curProgress = 0;
}
@Override
protected void onProgressUpdate(Integer... values) {
progress.setProgress(values[0]);
}
@Override
protected Void doInBackground(Void... arg0) {
// Calculate total size of all files
for (String path : myFiles) {
totProgress += getFileSize(path);
}
progress.setMax(totProgress);
String strDB3File = getFilesDir().getPath() + "/VideoHashes.db3";
sql3 = SQLiteDatabase.openDatabase(strDB3File, null,
SQLiteDatabase.CREATE_IF_NECESSARY);
try {
String mysql = "CREATE TABLE IF NOT EXISTS videohashes (id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, path TEXT NOT NULL, hash TEXT NOT NULL, date TEXT NOT NULL, size INTEGER, resolution TEXT NOT NULL, codec TEXT NOT NULL, format TEXT NOT NULL, fps TEXT NOT NULL)";
sql3.execSQL(mysql);
} catch (SQLiteException e) {
// TODO: handle exception
}
for (String path : myFiles) {
try {
String hash = getMD5Checksum(path);
Cursor curFrame = sql3.query("videohashes",
new String[] { "hash" }, "hash=?",
new String[] { hash }, null, null, null);
if (!curFrame.moveToFirst()) {
ContentValues myInsertData = new ContentValues();
myInsertData.put("path", path);
myInsertData.put("hash", hash);
Date date = new Date();
myInsertData.put("date", dateFormat.format(date));
myInsertData.put("size", getFileSize(path));
naInit(path);
Log.i("VPMA", "After naInit");
int[] prVideoRes = naGetVideoResolution();
myInsertData.put("resolution", prVideoRes[0] + "x"
+ prVideoRes[1]);
String prVideoCodecName = naGetVideoCodecName();
myInsertData.put("codec", prVideoCodecName);
String prVideoFormatName = naGetVideoFormatName();
myInsertData.put("format", prVideoFormatName);
double prFps = naGetVideoFPS();
Log.i("VPMA", "fps: " + prFps);
myInsertData.put("fps", prFps);
Object[] prObjArray = naGetArray();
Log.i("VPMA", (String) prObjArray[0]);
String[] prStrArray = Arrays.copyOf(prObjArray,
prObjArray.length, String[].class);
Log.i("VPMA", "before frames");
try {
String mysql = "CREATE TABLE table_"
+ hash
+ " (id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, type TEXT NOT NULL, cp_num TEXT NOT NULL, dp_num TEXT NOT NULL, pts TEXT NOT NULL, qstride TEXT NOT NULL, size TEXT NOT NULL, qp_stddev TEXT NOT NULL, count TEXT NOT NULL, qp_avg TEXT NOT NULL)";
sql3.execSQL(mysql);
} catch (SQLiteException e) {
// TODO: handle exception
}
for (String str : prStrArray) {
ContentValues myFrameInsertData = new ContentValues();
String[] strArr = str.split(",");
if (strArr.length == 9) {
String stddev = "", strCount = "", strQp_avg = "";
double sd, qp_avg, count = 0, sum = 0, sqrSum = 0;
try {
count = Integer.parseInt(strArr[6].trim());
sum = Integer.parseInt(strArr[7].trim());
sqrSum = Integer.parseInt(strArr[8].trim());
//sd = (sum * sum / count);
sd = (sqrSum - (sum*sum/count))/(count-1);//(sqrSum - sd) / (count - 1);
stddev = String.valueOf(sd);
qp_avg = sum / count;
strCount = String.valueOf(count);
strQp_avg = String.valueOf(qp_avg);
} catch (Exception e) {
Log.i("Error: ", "error converting values");
}
//Log.i("Java Code: ", "Sum: " + sum + " SqrSum: " + sqrSum + " Count: " + count);
//Log.i("Java Code: ", "StdDev: " + stddev + " qp_avg: " + strQp_avg);
myFrameInsertData.put("type", strArr[0]);
myFrameInsertData.put("cp_num", strArr[1]);
myFrameInsertData.put("dp_num", strArr[2]);
myFrameInsertData.put("pts", strArr[3]);
myFrameInsertData.put("qstride", strArr[4]);
myFrameInsertData.put("size", strArr[5]);
myFrameInsertData.put("qp_stddev", stddev);
myFrameInsertData.put("count", strCount);
myFrameInsertData.put("qp_avg", strQp_avg);
sql3.insert("table_" + hash, null,
myFrameInsertData);
}
}
sql3.insert("videohashes", null, myInsertData);
naClose();
}
curFrame.close();
currVid++;
curProgress += getFileSize(path);
publishProgress(curProgress);
Log.i("Progress", "CurrVid:" + currVid + " Max:"
+ progress.getMax());
} catch (Exception e) {
Log.i("File", "File not Found");
}
}
return null;
}
}
}
if (sharedPreferences.getBoolean("asyncTaskRunning", false) == false)
{
((Button) findViewById(R.id.btnStart)).setEnabled(false);
progress = (ProgressBar) findViewById(R.id.progressBar1);
text = (TextView) findViewById(R.id.tv1);
if (sharedPreferences.contains("lastVideoInfo"))
{
text.setText("Last Video Information Parsed " + "(" + dateFormat.format(dateNow) + "):\n\n" + sharedPreferences.getString("lastVideoInfo", ""));
((Button) findViewById(R.id.btnSend)).setEnabled(true);
}
else
{
text.setText("");
((Button) findViewById(R.id.btnSend)).setEnabled(false);
}
progress.setProgress(0);
myFiles = new ArrayList<String>();
new StartAsyncTask().execute();
}
}