我的MapActivity中有一个AsyncTask类。在doInBacground()方法中,我必须编码块。逻辑上正确,但'如果声明'与使我的应用程序崩溃的方法
它看起来像这样:
@Override
protected List<GeoPoint> doInBackground(String... arg0) {
// check if the query (word and the distance) existing queries and return its id
int checkQuery = db.getQueryMatch(arg0[3].toString() , arg0[2].toString());
Log.v(" CheckQuery int ", " equal? " + checkQuery);
if (checkQuery < 1)
{
Block 1
}
else
{
Block 2
}
getQueryMatch方法检查两个文本字段存在,则返回记录ID。
int getQueryMatch(String word, String meter) {
SQLiteDatabase db = this.getReadableDatabase();
int getidd = 0;
Cursor cursor = db.query(TABLE_HISTORY, new String[] { KEY_ID, QUERYWORD, DISTANCEQ, KEY_TIMESTAMP }, QUERYWORD + "=? AND " + DISTANCEQ + "=?", new String[] { word, meter }, null, null, null, null);
//String selectQuery = "SELECT * FROM " + TABLE_HISTORY + " WHERE " + QUERYWORD + "= '" + word + "' AND " + DISTANCEQ + "= '"+ meter +"'" ;
if (cursor != null)
cursor.moveToFirst();
getidd = Integer.parseInt(cursor.getString(0));
db.close(); // Closing database connection
// return History
return getidd;
}
当我测试了它没有if语句中的AsyncTask类,它工作得很好。如果返回的值为0,则会导致应用程序崩溃。 因此,如果没有从数据库中找到记录(由getQueryMatch检查),则要运行块1,否则请运行块2.
此处是错误:
10-19 02:47:50.464: E/AndroidRuntime(11967): FATAL EXCEPTION: AsyncTask #2
10-19 02:47:50.464: E/AndroidRuntime(11967): java.lang.RuntimeException: An error occured while executing doInBackground()
10-19 02:47:50.464: E/AndroidRuntime(11967): at android.os.AsyncTask$3.done(AsyncTask.java:299)
10-19 02:47:50.464: E/AndroidRuntime(11967): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
10-19 02:47:50.464: E/AndroidRuntime(11967): at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
10-19 02:47:50.464: E/AndroidRuntime(11967): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
10-19 02:47:50.464: E/AndroidRuntime(11967): at java.util.concurrent.FutureTask.run(FutureTask.java:137)
10-19 02:47:50.464: E/AndroidRuntime(11967): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
10-19 02:47:50.464: E/AndroidRuntime(11967): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
10-19 02:47:50.464: E/AndroidRuntime(11967): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
10-19 02:47:50.464: E/AndroidRuntime(11967): at java.lang.Thread.run(Thread.java:856)
10-19 02:47:50.464: E/AndroidRuntime(11967): Caused by: android.database.CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0
10-19 02:47:50.464: E/AndroidRuntime(11967): at android.database.AbstractCursor.checkPosition(AbstractCursor.java:418)
10-19 02:47:50.464: E/AndroidRuntime(11967): at android.database.AbstractWindowedCursor.checkPosition(AbstractWindowedCursor.java:136)
10-19 02:47:50.464: E/AndroidRuntime(11967): at android.database.AbstractWindowedCursor.getString(AbstractWindowedCursor.java:50)
10-19 02:47:50.464: E/AndroidRuntime(11967): at com.example.phooogle.DatabaseHandler.getQueryMatch(DatabaseHandler.java:148)
10-19 02:47:50.464: E/AndroidRuntime(11967): at com.example.phooogle.GoogleMapsAppActivity$InitTask.doInBackground(GoogleMapsAppActivity.java:142)
10-19 02:47:50.464: E/AndroidRuntime(11967): at com.example.phooogle.GoogleMapsAppActivity$InitTask.doInBackground(GoogleMapsAppActivity.java:1)
10-19 02:47:50.464: E/AndroidRuntime(11967): at android.os.AsyncTask$2.call(AsyncTask.java:287)
10-19 02:47:50.464: E/AndroidRuntime(11967): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
对我来说这是逻辑上真实的,但不工作!
在这种情况下,如果它是真的我可以返回的ID? – iAziz
检查编辑。 – nandeesh
对不起,我不得不改变别的东西,现在它工作得很完美。谢谢sooo多:) – iAziz