从SQLite数据库（Android Studio）检索数据时出现问题

Question

我无法从以下代码 ::

中检索数据

APP在Fetching Block受到攻击。该应用程序正在运行向上获取阻止，但是当它进入获取阻止它没有响应时，模拟器在按下＆＃34后没有响应; 提交 ＆＃34;按钮。

public void submitButtonClicked(View view) {


    eventName= (EditText) findViewById(R.id.eventName);
    eventDate= (EditText) findViewById(R.id.eventDate);
    sumbitButton= (Button) findViewById(R.id.submit);

    System.out.println("Taken data!");
    String ename= eventName.getText().toString();
    String edate= eventDate.getText().toString();
    String dbString;
    dbAdapter = new DBAdapter(this);
    dbAdapter.open();

    try {
        dbAdapter.createEvent(ename, edate);
    }
    catch (SQLException e) {
        Toast.makeText(MembersActivity.this, "Some problem occurred",
                Toast.LENGTH_LONG).show();

    }
    System.out.println("Written data to table!");
    setContentView(R.layout.event);
    System.out.println("With event file!");

    //Fetch Block starts here
    try {
        dbString = dbAdapter.databaseToString();
        System.out.println("Fetched data!");
        myText.setText(dbString);
        myText.setText(" ");

    }
    catch (Exception e){
        System.out.println("Problem in Fetching data!");
        e.printStackTrace();
    }

}

函数databaseToString位于下面 ::

//Print out the database as a string
public String databaseToString() {
    String dbString="";
    mDbHelper = new DBHelper(mCtx);
    SQLiteDatabase db = mDbHelper.getReadableDatabase();
    String query="select * from events where 1";

    //Cursor point to a location in your results
    Cursor c = db.rawQuery(query,null);

    //Move to the first row in your results
    c.moveToFirst();

    while(!c.isAfterLast()){
        if(c.getString(c.getColumnIndex("eventname"))!= null){
            dbString+=c.getString(c.getColumnIndex("eventname"));
            //dbString+=c.getString(c.getColumnIndex("eventdate"));

            dbString+="\n";

        }
    }
    db.close();
    return dbString;
}