Windows Phone - 独立存储异常

Question

下面的代码捕获用户选择的服务器路径并保存在IsolatedStorage上：

private void ConfSalvar(object sender, RoutedEventArgs e)
{
    IsolatedStorageSettings iso = IsolatedStorageSettings.ApplicationSettings;

    if (iso.Contains("isoServer"))
    {
        iso["isoServer"] = server.Text;
    }
    else
    {
        iso.Add("isoServer", server.Text);
    }

}

下一个代码（另一个屏幕），使用隔离存储中保存的服务器路径来创建一个 URL：

IsolatedStorageSettings iso = IsolatedStorageSettings.ApplicationSettings;



if (iso.TryGetValue<string>("isoServer", out retornaNome))
{
    serv = retornaNome;
}


 private void sinc(object sender, EventArgs e)
 {
     order.Visibility = Visibility.Collapsed;

     client = new WebClient();
     url = serv + "/json.html";
     Uri uri = new Uri(url, UriKind.RelativeOrAbsolute);
     client.OpenReadCompleted += new OpenReadCompletedEventHandler(client_OpenReadCompleted);
     client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(client_DownloadProgressChanged);
     client.OpenReadAsync(uri);
}

private void client_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
{
    string strFileName = url.Substring(url.LastIndexOf("/") + 1, (url.Length - url.LastIndexOf("/") - 1));
    IsolatedStorageFile isoStore = IsolatedStorageFile.GetUserStoreForApplication();
    //  Path Storage
    // *** If File Exists
    if (isoStore.FileExists(strFileName))
    {
        isoStore.DeleteFile(strFileName);
    }
    IsolatedStorageFileStream dataFile = new IsolatedStorageFileStream(strFileName, FileMode.CreateNew, isoStore);

    long fileLen = e.Result.Length;
    byte[] b = new byte[fileLen];
    e.Result.Read(b, 0, b.Length);
    dataFile.Write(b, 0, b.Length);
    dataFile.Flush();
    object lenghtOfFile = dataFile.Length;
    dataFile.Close();

    order.Visibility = Visibility.Visible;
    ProgressBar1.Visibility = Visibility.Collapsed;
    MessageBox.Show("Arquivo salvo!");
}

private void client_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e)
{
    ProgressBar1.Visibility = Visibility.Visible;
    this.ProgressBar1.Value = e.ProgressPercentage;            
}

所以，如果我保存了文件路径并在单击“sinc”按钮后立即出现异常“操作过程中发生异常，导致结果无效。请检查 InnerException 以获取异常详细信息。”。 但是如果我保存文件路径并关闭应用程序，打开应用程序并单击“sinc”按钮，它可以工作。

抱歉英语不好

Answer 1

这与IsolatedStorageSettings 无关。它工作正常。问题是当您创建Uri 时，您将UriKind 设置为RelativeOrAbsolute。

这就是抛出异常的原因，而 InnerException 声明 This operations is not supported for a relative URI。您需要做的是将UriKind 更改为Absolute。所以代码块应该是这样的。

private void sinc(object sender, EventArgs e)
{
    if (iso.TryGetValue<string>("isoServer", out retornaNome))
    {
        serv = retornaNome;
    } 
    else 
    {
        // Let the user know.
        return;
    }

    order.Visibility = Visibility.Collapsed;

    client = new WebClient();
    url = serv + "/json.html";
    Uri uri = new Uri(url, UriKind.Absolute); // <<< Absolute instead of RelativeOrAbsolute
    client.OpenReadCompleted += new OpenReadCompletedEventHandler(client_OpenReadCompleted);
    client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(client_DownloadProgressChanged);
    client.OpenReadAsync(uri);
}

这应该可以解决您的问题并且可以正常工作:)