如何從數據庫中獲取項目的值並將其設置爲微調值

Question

我有一個數據庫並且數據庫填充了一個列表視圖。當我長按列表視圖中的列表項時，我得到一個上下文菜單，我可以選擇編輯。當點擊編輯選項時，我打開一個活動並從數據庫中獲取各個字段的所有值。現在，我想從數據庫中獲取一個值並將其顯示在微調器中。微調已經有了這些值，並從數據庫中得到填充。我曾嘗試以下，但我得到一個錯誤說我不能投了SimpleCursorAdapter到ArrayAdapter ..

 String osub = cursor.getString(Database.INDEX_SUBJECT); 
     Cursor cs = mDBS.querySub(osub); 
     String subs = cs.getString(DatabaseSub.INDEX_SSUBJECT); 
     if(cs!=null){ 
      ArrayAdapter<String> myAdap = (ArrayAdapter<String>) subSpinner.getAdapter(); 
           //cast to an ArrayAdapter 

      int spinnerPosition = myAdap.getPosition(subs); 

      //set the default according to value 
      subSpinner.setSelection(spinnerPosition); 

請告訴我如何做到這一點..謝謝..我比較新，所以請讓我知道，如果我忽略了一些東西。

謝謝..

編輯

querySub方法

public Cursor querySub(String sub) throws SQLException { 
    Cursor cursor = mDatabase.query(true, DATABASE_TABLE, sAllColumns, "ssub like " + "'" + sub + "'", null, null, null, null, null); 
    if (cursor.moveToNext()) { 
     return cursor; 
    } 
    cursor.moveToFirst(); 
    return cursor; 
} 

Error Log

06-05 12:11:14.144: E/AndroidRuntime(775): FATAL EXCEPTION: main 
06-05 12:11:14.144: E/AndroidRuntime(775): java.lang.RuntimeException: Unable to start activity ComponentInfo{an.droid.kit/an.droid.kit.DetailsActivity}: java.lang.ClassCastException: android.widget.SimpleCursorAdapter cannot be cast to android.widget.ArrayAdapter 
06-05 12:11:14.144: E/AndroidRuntime(775): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956) 
06-05 12:11:14.144: E/AndroidRuntime(775): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981) 
06-05 12:11:14.144: E/AndroidRuntime(775): at android.app.ActivityThread.access$600(ActivityThread.java:123) 
06-05 12:11:14.144: E/AndroidRuntime(775): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147) 
06-05 12:11:14.144: E/AndroidRuntime(775): at android.os.Handler.dispatchMessage(Handler.java:99) 
06-05 12:11:14.144: E/AndroidRuntime(775): at android.os.Looper.loop(Looper.java:137) 
06-05 12:11:14.144: E/AndroidRuntime(775): at android.app.ActivityThread.main(ActivityThread.java:4424) 
06-05 12:11:14.144: E/AndroidRuntime(775): at java.lang.reflect.Method.invokeNative(Native Method) 
06-05 12:11:14.144: E/AndroidRuntime(775): at java.lang.reflect.Method.invoke(Method.java:511) 
06-05 12:11:14.144: E/AndroidRuntime(775): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) 
06-05 12:11:14.144: E/AndroidRuntime(775): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 
06-05 12:11:14.144: E/AndroidRuntime(775): at dalvik.system.NativeStart.main(Native Method) 
06-05 12:11:14.144: E/AndroidRuntime(775): Caused by: java.lang.ClassCastException:  android.widget.SimpleCursorAdapter cannot be cast to android.widget.ArrayAdapter 
06-05 12:11:14.144: E/AndroidRuntime(775): at an.droid.kit.DetailsActivity.dbToUI(DetailsActivity.java:217) 
06-05 12:11:14.144: E/AndroidRuntime(775): at an.droid.kit.DetailsActivity.onCreate(DetailsActivity.java:104) 
06-05 12:11:14.144: E/AndroidRuntime(775): at android.app.Activity.performCreate(Activity.java:4465) 
06-05 12:11:14.144: E/AndroidRuntime(775): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049) 
06-05 12:11:14.144: E/AndroidRuntime(775): at  android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920) 
06-05 12:11:14.144: E/AndroidRuntime(775): ... 11 more 

Answer 1

我也遇到了類似的問題。 問題：我必須將微調器設置爲特定的字符串值，而不知道微調器控件本身的字符串值是多少。我創建的工作是採取微調控制並循環顯示其文本值。在每個位置比較spinners文本值和我想要設置的給定字符串值。如果它匹配，那麼得到當前位置並根據該位置設置我的紡紗器選擇。

int spinnerPosition = 0; 

for (int i = 0; i < yourSpinner.getCount(); i++) 
{ 
    Cursor cur = (Cursor)(yourSpinner.getItemAtPosition(i)); 

    //--When your bind you data to the spinner to begin with, whatever columns you 
    //--used you will need to reference it in the cursors getString() method... 

    //--Since "getString()" returns the value of the requested column as a String-- 
    //--(In my case) the 4th column of my spinner contained all of my text values 
    //--hence why I set the index of "getString()" method to "getString(3)" 

    String currentSpinnerString = cur.getString(3).toString(); 
    if(currentSpinnerString.contains("place string you want to set the spinner to here")) 
    { 
     //--get the spinner position-- 
     spinnerPosition = i; 
     break; 
     } 
} 

yourSpinner.setSelection(spinnerPosition);