CursorIndexOutOfBoundsException無法解析

我正在獲取遊標索引越界「索引0請求：大小爲0」。它只是一個用戶註冊和登錄應用程序。當沒有與用戶名和密碼匹配的用戶時，我的應用程序就會崩潰。CursorIndexOutOfBoundsException無法解析

下面是代碼：

MainActivity.java

final SUSQLiteHelper dbhelper = new SUSQLiteHelper(this); 

LoginData login = dbhelper.readOneUser(loginuname.getText().toString(), loginpwd.getText().toString()); 

       if(login.getUname().toString().equals(loginuname.getText().toString()) && 
         login.getPwd().toString().equals(loginpwd.getText().toString())) 
       { 
        Toast.makeText(getApplicationContext(), "Login Successfull. Welcome " + login.getUname().toUpperCase() +" !".toString(), 
          Toast.LENGTH_LONG).show(); 
       } 
       else if(login.getUname().toString().equals(loginuname.getText().toString()) && 
          !login.getPwd().toString().equals(loginpwd.getText().toString())) 
       {      
        Toast.makeText(getApplicationContext(), "Login Failed. Incorrect password !", 
          Toast.LENGTH_LONG).show();      
       } 
       else 
        Toast.makeText(getApplicationContext(), "Login Failed. User doesn't exist !", 
          Toast.LENGTH_LONG).show(); //it never goes here if no username is found in the table

SUSQLiteHelper.java

public LoginData readOneUser(String uname, String pwd) 
{ 
    SQLiteDatabase loginUserDB = this.getReadableDatabase(); 
    LoginData newLogin = null; 
    Cursor cursor = loginUserDB.query(TABLE_NAME, new String[]{TABLE_ROW_UNAME, TABLE_ROW_EMAIL, TABLE_ROW_PWD}, TABLE_ROW_UNAME + "=?", 
      new String[]{String.valueOf(uname)}, null, null, null); 

    if(cursor.moveToFirst()) 
    { 
     newLogin = new LoginData(cursor.getString(0), cursor.getString(1), cursor.getString(2)); 
    } 
    cursor.close(); 
    loginUserDB.close(); 
    return newLogin; 
}

LoginData.java

該類具有Uname，Pwd，Email字段的getter和setter方法以及將這些字段作爲參數的構造方法。

來源

2013-01-09 Srujan Simha

錯誤日誌請 – ePeace

@ePeace這裏是我的日誌... 01-09 19：12：16.440：E/AndroidRuntime（308）：android.database.CursorIndexOutOfBoundsException：指數0請求，大小爲0 –

CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0

這意味着cursor.moveToFirst() returns false和Cursor is empty。因此，嘗試添加代碼片段來檢查遊標是否爲空，並依賴於修改您的邏輯。

public LoginData readOneUser(String uname, String pwd) 
{ 
SQLiteDatabase loginUserDB = this.getReadableDatabase(); 
LoginData newLogin = null; 
Cursor cursor = loginUserDB.query(TABLE_NAME, new String[]{TABLE_ROW_UNAME, TABLE_ROW_EMAIL,TABLE_ROW_PWD}, TABLE_ROW_UNAME + "=?",new String[]{String.valueOf(uname)}, null, null, null); 

    if(cursor!=null) //Check whether cursor is null or not 
    { 
    if(cursor.moveToFirst()) 
    { 
    newLogin = new LoginData(cursor.getString(0), cursor.getString(1), cursor.getString(2)); 
    } 
    } 
cursor.close(); 
loginUserDB.close(); 
return newLogin; 
}

LoginData login = dbhelper.readOneUser(loginuname.getText().toString(), loginpwd.getText().toString()); 
    if(login!=null) 
    { 
    //check for incorrect username or password 
    } 
    else 
    { 
    //Notify that no Username available with these Username 
    }

來源

2013-01-09 15:19:55

謝謝！它的工作:) –

在功能readOneUser（），檢查：

if(cursor.moveToFirst() && !cursor.isAfterLast()) { 
    // 
}

來源

2013-01-09 15:18:46

CursorIndexOutOfBoundsException無法解析

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