CODEWITHSUNDEEP
androidsqlite
Amrmsmb
Amrmsmb

Reputation: 1

error when getting the number of rows in a cursor?

I dont know why the App. crashs when i try to display the number of selected rows inside a cursor. when I comment on the line that displays the number of selected rows the App. works fine otherwise it crashs.

Here is the code:

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    dbd = new DBDemoActivity(this);
    db = dbd.getWritableDatabase();
    cv = new ContentValues();

    cv.put("name", "Amr");
    cv.put("lat", 10);
    cv.put("lng", 20);
    newID = db.insert("Demo", null, cv);

    cv.put("name", "Mikila");
    cv.put("lat", 14);
    cv.put("lng", 22);
    newID = db.insert("Demo", null, cv);

    cv.put("name", "bakri");
    cv.put("lat", 17);
    cv.put("lng", 29);
    newID = db.insert("Demo", null, cv);

    cv.put("name", "geomatics");
    cv.put("lat", 50);
    cv.put("lng", 90);
    newID = db.insert("Demo", null, cv);
    }        

    SQLiteCursor c = (SQLiteCursor) db.rawQuery("SELECT * FROM Demo WHERE lat = 10", null);
    //c.moveToFirst();
    //Toast.makeText(getBaseContext(), c.getCount(), Toast.LENGTH_SHORT).show();
    //dbd.deleteMP(1);   
}

}

LogCat:

02-27 10:46:35.675: E/AndroidRuntime(25525): FATAL EXCEPTION: main
02-27 10:46:35.675: E/AndroidRuntime(25525): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.androidbook.DBDemo/com.androidbook.DBDemo.DemoData}: android.content.res.Resources$NotFoundException: String resource ID #0x9
02-27 10:46:35.675: E/AndroidRuntime(25525):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1651)
02-27 10:46:35.675: E/AndroidRuntime(25525):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1667)
02-27 10:46:35.675: E/AndroidRuntime(25525):    at android.app.ActivityThread.access$1500(ActivityThread.java:117)
02-27 10:46:35.675: E/AndroidRuntime(25525):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:935)
02-27 10:46:35.675: E/AndroidRuntime(25525):    at android.os.Handler.dispatchMessage(Handler.java:99)
02-27 10:46:35.675: E/AndroidRuntime(25525):    at android.os.Looper.loop(Looper.java:123)
02-27 10:46:35.675: E/AndroidRuntime(25525):    at android.app.ActivityThread.main(ActivityThread.java:3691)
02-27 10:46:35.675: E/AndroidRuntime(25525):    at java.lang.reflect.Method.invokeNative(Native Method)
02-27 10:46:35.675: E/AndroidRuntime(25525):    at java.lang.reflect.Method.invoke(Method.java:507)
02-27 10:46:35.675: E/AndroidRuntime(25525):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:847)
02-27 10:46:35.675: E/AndroidRuntime(25525):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:605)
02-27 10:46:35.675: E/AndroidRuntime(25525):    at dalvik.system.NativeStart.main(Native Method)
02-27 10:46:35.675: E/AndroidRuntime(25525): Caused by: android.content.res.Resources$NotFoundException: String resource ID #0x9
02-27 10:46:35.675: E/AndroidRuntime(25525):    at android.content.res.Resources.getText(Resources.java:222)
02-27 10:46:35.675: E/AndroidRuntime(25525):    at android.widget.Toast.makeText(Toast.java:258)
02-27 10:46:35.675: E/AndroidRuntime(25525):    at com.androidbook.DBDemo.DemoData.onCreate(DemoData.java:54)
02-27 10:46:35.675: E/AndroidRuntime(25525):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
02-27 10:46:35.675: E/AndroidRuntime(25525):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1615)
02-27 10:46:35.675: E/AndroidRuntime(25525):    ... 11 more

Upvotes: 1

Views: 716

Answers (2)

josephus
josephus

Reputation: 8304

The problem is with Toast.makeText. makeText() is an overloaded method which comes in two flavors - 

makeText(Context c, String s, int duration)

and 

makeText(Context, int resId, int duration)

What you're using is the second one (the one with resId) - since cursor.getCount returns an integer. Now android is trying to find (in your Resources class @gen folder) which String is the value of cursor.getCount affiliated with. Since it can't find one, it throws a Resources$NotFoundException.

fix: instead of cursor.getCount(), try (String.valueOf(cursor.getCount()))

Upvotes: 1

Snicolas
Snicolas

Reputation: 38168

How does it crash ? You have to find out the details of your error. ow can you understand problems you don't precisely understand ?

Look at your logcat details and find the culprit and the type of the error.

Chances are :

  • you request takes too long. It's not a very good idea to have a DB request in the onCreate method. This method is executed on the UI thread and after 5 seconds of inactivity, your app will crash with an ANR. You would be better served by an asynctask.
  • getBaseContext() seems funny, use this.

------- UPDATE -----

Your problem is that you pass an int to Toast. It then expects the int to represent a resourceId.

If you had passed a string, you wouldn't have had this problem. Use 

 Toast.makeText(getBaseContext(), String.valueOf( c.getCount() ), toast.LENGTH_SHORT).show();

Upvotes: 0

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