1
我只有一個SQLite表只用於測試某些東西,但我不知道應用程序崩潰的原因。該應用程序。在數據庫中插入一行時發生崩潰
這裏是SQLite的類:
public class DBDemoActivity extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 2;
private static final String DATABASE_NAME = "DBDemo.db";
private static final String MP_TABLE_NAME = "Demo";
DBDemoActivity (Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}// end of
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
db.execSQL(" CREATE TABLE " + MP_TABLE_NAME + " (" +
BaseColumns._ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
" name TEXT, " +
" lat REAL, " +
" lng REAL " +
");");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
}
public String getName(long id) {
SQLiteDatabase db = this.getReadableDatabase();
SQLiteCursor c = (SQLiteCursor) db.rawQuery("SELECT name FROM Demo WHERE "+
BaseColumns._ID+" = "+
Long.toString(id), null);
countRows(c);
c.moveToFirst();
String r = c.getString(0);
c.close();
db.close();
return r;
}
public int countRows(SQLiteCursor c) {
return c.getCount();
}
}
和這裏的活動:
public class DemoData extends Activity{
DBDemoActivity dbd;
SQLiteDatabase db;
ContentValues cv;
@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);
long newID = db.insert("Demo", null, cv);
if (newID != -1){
Toast.makeText(getBaseContext(),
"data saved ",
Toast.LENGTH_SHORT).show();
}// end if*/
}
}
這裏是logcat的:
02-26 20:28:55.530: E/AndroidRuntime(17124): FATAL EXCEPTION: main
02-26 20:28:55.530: E/AndroidRuntime(17124): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.androidbook.DBDemo/com.androidbook.DBDemo.DBDemoActivity}: java.lang.InstantiationException: com.androidbook.DBDemo.DBDemoActivity
02-26 20:28:55.530: E/AndroidRuntime(17124): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1573)
02-26 20:28:55.530: E/AndroidRuntime(17124): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1667)
02-26 20:28:55.530: E/AndroidRuntime(17124): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
02-26 20:28:55.530: E/AndroidRuntime(17124): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:935)
02-26 20:28:55.530: E/AndroidRuntime(17124): at android.os.Handler.dispatchMessage(Handler.java:99)
02-26 20:28:55.530: E/AndroidRuntime(17124): at android.os.Looper.loop(Looper.java:123)
02-26 20:28:55.530: E/AndroidRuntime(17124): at android.app.ActivityThread.main(ActivityThread.java:3691)
02-26 20:28:55.530: E/AndroidRuntime(17124): at java.lang.reflect.Method.invokeNative(Native Method)
02-26 20:28:55.530: E/AndroidRuntime(17124): at java.lang.reflect.Method.invoke(Method.java:507)
02-26 20:28:55.530: E/AndroidRuntime(17124): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:847)
02-26 20:28:55.530: E/AndroidRuntime(17124): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:605)
02-26 20:28:55.530: E/AndroidRuntime(17124): at dalvik.system.NativeStart.main(Native Method)
02-26 20:28:55.530: E/AndroidRuntime(17124): Caused by: java.lang.InstantiationException: com.androidbook.DBDemo.DBDemoActivity
02-26 20:28:55.530: E/AndroidRuntime(17124): at java.lang.Class.newInstanceImpl(Native Method)
02-26 20:28:55.530: E/AndroidRuntime(17124): at java.lang.Class.newInstance(Class.java:1409)
02-26 20:28:55.530: E/AndroidRuntime(17124): at android.app.Instrumentation.newActivity(Instrumentation.java:1021)
02-26 20:28:55.530: E/AndroidRuntime(17124): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1565)
02-26 20:28:55.530: E/AndroidRuntime(17124): ... 11 more
重組你的logcat,並檢查您在manifiest文件中添加你的活動 – 2012-02-26 19:40:37
我已經加入這兩項活動清單 – LetsamrIt 2012-02-26 19:51:21
@ user1121443:如果您的意思是您的清單中有'DBDemoActivity'條目,那麼您不應該有。它是一個'SQLiteOpenHelper'而不是'Activity',所以不應該被命名爲一個,並且在清單文件中不應該有任何地方的任何條目。 – Squonk 2012-02-26 19:56:08