java - 无法从 CursorWindow 读取第 0 行第 2 列

Question

我尝试使用上下文菜单从 ListView 中删除数据，但出现 java.lang.IllegalStateException: Couldn't read row 0, col 2 from CursorWindow。在访问游标中的数据之前，请确保游标已正确初始化。

       public List<AssignmentRecord> getAllAssignment(){
    List<AssignmentRecord> records = new ArrayList<AssignmentRecord>();
    Cursor cursor = database.query(AssigmentContract.Assigment.TABLE_NAME, allColumn , null,
            null, null, null, null);
    cursor.moveToFirst();
    while(!cursor.isAfterLast()){
        AssignmentRecord assignmentRecord = new AssignmentRecord();
        assignmentRecord.setAssname(cursor.getString(0));
        assignmentRecord.setAssTime(cursor.getString(1));
        assignmentRecord.setAssID(cursor.getString(2));
        records.add(assignmentRecord);
        cursor.moveToNext();
    }

第一行错误赋值Record.setAssID(cursor.getString(2));

     dbcon.open();
    List<AssignmentRecord> records = dbcon.getAllAssignment();
    dbcon.close();

第二个错误是列出记录= dbcon.getAllAssignment();

private static final String SQL_CREATE_ENTRIES = "CREATE TABLE "
        + AssigmentContract.Assigment.TABLE_NAME +
                "(" + AssigmentContract.Assigment.COLUMN_ID
                + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
                AssigmentContract.Assigment.COLUMN_ASS + " TEXT," +
                AssigmentContract.Assigment.COLUMN_ASSDATE+ " TEXT)";


       public final class AssigmentContract {
              public AssigmentContract(){}

public static abstract class Assigment implements BaseColumns{
    public static final String TABLE_NAME ="AssignmentV2";
    public static final String COLUMN_ASS ="AssignmentTitle";
    public static final String COLUMN_ASSDATE ="AssignmentDate";
    public static final String COLUMN_ID ="AssignmentID";
      }
       }

LOGCAT

     my.com.chyi.schedulev2 E/CursorWindow﹕ Failed to read row 0, column 2 from a CursorWindow which has 1 rows, 2 columns.
     my.com.chyi.schedulev2 D/AndroidRuntime﹕ Shutting down VM
           my.com.chyi.schedulev2 W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0x9e4f5908)
         /my.com.chyi.schedulev2 E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{my.com.chyi.schedulev2/my.com.chyi.schedulev2.assigmentActivity}: java.lang.IllegalStateException: Couldn't read row 0, col 2 from CursorWindow.  Make sure the Cursor is initialized correctly before accessing data from it.
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
        at android.app.ActivityThread.access$600(ActivityThread.java:141)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:137)
        at android.app.ActivityThread.main(ActivityThread.java:5041)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:511)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
        at dalvik.system.NativeStart.main(Native Method)
 Caused by: java.lang.IllegalStateException: Couldn't read row 0, col 2 from CursorWindow.  Make sure the Cursor is initialized correctly before accessing data from it.
        at android.database.CursorWindow.nativeGetString(Native Method)
        at android.database.CursorWindow.getString(CursorWindow.java:434)
        at android.database.AbstractWindowedCursor.getString(AbstractWindowedCursor.java:51)
        at my.com.chyi.schedulev2.SQLController.getAllAssignment(SQLController.java:102)
        at my.com.chyi.schedulev2.assigmentActivity.onCreate(assigmentActivity.java:73)
        at android.app.Activity.performCreate(Activity.java:5104)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)                 at  android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)

在 android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230在 android.app.ActivityThread.access$600(ActivityThread.java:141) 在 android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234 在 android.os.Handler.dispatchMessage(Handler.java:99) 在 android.os.Looper.loop(Looper.java:137) 在 android.app.ActivityThread.main(ActivityThread.java:5041) 在 java.lang.reflect.Method.in vokeNative( native 方法)at java.lang.reflect.Method.invoke(Method.java:511)在 com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)在 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)在dalvik.system.NativeStart.main( native 方法)

Answer 1

试试这个，

while(!cursor.isAfterLast()){
        AssignmentRecord assignmentRecord = new AssignmentRecord();
        assignmentRecord.setAssname(cursor.getString(cursor.getColumnIndex("your_respective_column_name));
        assignmentRecord.setAssTime(cursor.getString(cursor.getColumnIndex("your_respective_column_name)));
        assignmentRecord.setAssID(cursor.getString(cursor.getColumnIndex("your_respective_column_name)));
        records.add(assignmentRecord);
        cursor.moveToNext();

我已经演示了哈利建议你做的事情。此处将 your_respective 列名称替换为您为尝试检索的列指定的值。例如:当您尝试获取 AssId 的值时，它将是 _id 或其他东西。希望这对您有帮助。