windows phone 7 中的隔离存储异常答案

【问题标题】：Isolated storage exception in windows phone 7windows phone 7 中的隔离存储异常
【发布时间】：2011-07-25 14:18:12
【问题描述】：

我正在尝试做一个设置页面，用户可以在其中从 listpicker 控件中选择问题、歌曲和通过率的数量..

然后将题目、歌曲和通过率的选定索引写入隔离存储。

下面是我的代码：

int indexQues;

    string rate;
    private void saveBtn_Click(object sender, RoutedEventArgs e)
    {
        using (IsolatedStorageFile myIsolatedStorage = IsolatedStorageFile.GetUserStoreForApplication()) 
        {
            if (myIsolatedStorage.FileExists("SettingFolder\\queSetting.txt")) 
            {
                myIsolatedStorage.DeleteFile("SettingFolder\\queSetting.txt");
            }

            if (myIsolatedStorage.FileExists("SettingFolder\\rateSetting.txt"))
            {
                myIsolatedStorage.DeleteFile("SettingFolder\\rateSetting.txt");
            }
        } 

        indexQues = queListPicker.SelectedIndex;
        rate = rateListPicker.SelectedItem.ToString();

        //Save the number of question to answer when the alarm ring
        //Obtain the virtual store for application
        IsolatedStorageFile myStore = IsolatedStorageFile.GetUserStoreForApplication();
        IsolatedStorageFile myStore1 = IsolatedStorageFile.GetUserStoreForApplication();
        //Create a new folder and call it "AlarmFolder"
        myStore.CreateDirectory("SettingFolder");

        //Retrieve the content of "noOfQues"
        //And write it into queSetting.txt
        StreamWriter writeFile = new StreamWriter(new IsolatedStorageFileStream("SettingFolder\\queSetting.txt", FileMode.Append, myStore));
        StreamWriter writeFile1 = new StreamWriter(new IsolatedStorageFileStream("SettingFolder\\rateSetting.txt", FileMode.Append, myStore));

        writeFile.Write(indexQues);
        writeFile1.Write(rate);
        writeFile.Close();
        writeFile1.Close();

        MessageBox.Show("Setting Saved");
        NavigationService.Navigate(new Uri("/MainPage.xaml", UriKind.Relative));
    }

上面的代码允许我写入隔离存储，但是当我第三次尝试保存时出现错误。

错误是“IsolatedStorageException 未处理” 访问 IsolatedStorage 时出错。

【问题讨论】：

标签： windows-phone-7 isolatedstorage

【解决方案1】：

我不确定这是否是您的问题的原因，但我从未使用 StreamWriter 写入隔离存储。尝试将编写代码更改为以下内容：

//Save the number of question to answer when the alarm ring
//Obtain the virtual store for application
IsolatedStorageFile myStore = IsolatedStorageFile.GetUserStoreForApplication();

//Create a new folder and call it "AlarmFolder"
myStore.CreateDirectory("SettingFolder");

//Retrieve the content of "noOfQues"
//And write it into queSetting.txt
using( IsolatedStorageFileStream isoStream =
  new IsolatedStorageFileStream("SettingFolder\\queSetting.txt", 
    FileMode.Append, myStore)) ) {

      byte[] indexBytes = UTF8Encoding.UTF8.GetBytes( indexQues.ToString() );

      isoStream.Write(indexBytes, 0, indexBytes.Length);
      isoStream.Flush();
}

using( IsolatedStorageFileStream isoStream =
  new IsolatedStorageFileStream("SettingFolder\\rateSetting.txt", 
    FileMode.Append, myStore)) ) {

      byte[] rateBytes = UTF8Encoding.UTF8.GetBytes( rate );

      isoStream.Write(rateBytes, 0, rateBytes.Length);
      isoStream.Flush();
}

【讨论】：

嗨。我尝试将代码编辑为您的上述代码，但在“isoStrem.Write(indexQues);”上出现错误和“isoStrem.Write(rate);”错误是“方法'Write'没有重载需要1个参数。如何修改它？
@ben tan：抱歉，我忘了将参数转换为字节数组。 IsolatedStorageFileStream.Write 只会写一个byte[] 或一个byte。我已经编辑了答案。
已更改为您的更新代码。但是第三次保存还是有错误。 isoStream 变为空。

【解决方案2】：

这里有很多很棒的示例和演练，它们教会了我很多东西！

http://channel9.msdn.com/blogs/egibson/windows-phone-7-jump-start-session-7-of-12-advanced-application-development-part-1

【讨论】：