关闭后尝试访问游标

Question

我正在使用以下代码删除图像.它第一次工作,但当我尝试捕获图像并删除它时,我得到一个StaleDataException:

08-07 14:57:24.156: E/AndroidRuntime(789): java.lang.RuntimeException: Unable to               
       resume activity {com.example.cap_im/com.example.cap_im.MainActivity}:  
       android.database.StaleDataException: Attempted to access a cursor after it has been closed.

---

public void deleteImageFromGallery(String captureimageid) {
    Uri u = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;

    getContentResolver().delete(
            MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
            BaseColumns._ID + "=?", new String[] { captureimageid });

    String[] projection = { MediaStore.Images.ImageColumns.SIZE,
            MediaStore.Images.ImageColumns.DISPLAY_NAME,
            MediaStore.Images.ImageColumns.DATA, BaseColumns._ID, };

    Log.i("InfoLog", "on activityresult Uri u " + u.toString());

    try {
        if (u != null) {
            cursor = managedQuery(u, projection, null, null, null);
        }
        if ((cursor != null) && (cursor.moveToLast())) {

            int i = getContentResolver().delete(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                    BaseColumns._ID + "=" + cursor.getString(3),   null);
            Log.v(TAG, "Number of column deleted : " + i);
        }
    } finally {
        if (cursor != null) {
            cursor.close();
        }
    }
}

Answer 1

功能,managedQuery()已弃用.

请使用getContentResolver().query().

参数是相同的.

Answer 2

在finally块中,关闭光标,但不要将其设置为null.因此,下次调用方法cursor.getString(3)失败,因为游标已关闭.

解决方法:cursor要null在你的finally块.

正确的解决方案:不要为您使用实例变量,cursor而是在您的方法中使用局部变量.