Silverlight WebClient 渐进式下载

发布于 2024-07-25 04:08:35 字数 834 浏览 5 评论 0原文

我正在尝试逐步下载一系列序列化数据。目标是从服务器发送单个大块，并在下载时在客户端上部分处理它。

我正在使用 System.Net.WebClient 类并将其AllowReadStreamBuffering 属性设置为 false。根据 MSDN 文档，这应该允许我访问来自 OpenReadCompleted 事件的传入流。

然而，当我尝试访问该流时，它会抛出 NotSupportedException。这不是跨域策略问题，如果我将AllowReadStreamBuffering 属性设置为true，它将完美加载和读取内容。我错过了什么吗？我应该如何从 Silverlight 执行渐进式下载？

复制此问题的最少代码如下：

    private void BeginProgressiveDownload()
    {
        WebClient client = new WebClient();
        client.AllowReadStreamBuffering = false;
        client.OpenReadCompleted += new OpenReadCompletedEventHandler(client_OpenReadCompleted);
        client.OpenReadAsync(new Uri("http://STREAMABLE RESOURCE HERE"));
    }

    void client_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
    {
        e.Result.ReadByte();
    }

原文

I'm trying to progressively download an array of serialised data. The goal is to send a single large block from the server, and partially process it on the client whilst it downloads.

I'm using the System.Net.WebClient class and setting it's AllowReadStreamBuffering property to false. According to the MSDN documentation, this should allow me to access the incoming stream from the OpenReadCompleted event.

When I attempt to access the stream, however, it throws a NotSupportedException. This is not a cross-domain policy issue, and if I set the AllowReadStreamBuffering property to true it loads and reads the content perfectly. Am I missing something? How should I perform progressive downloads from Silverlight?

The minimal code to replicate this problem is this:

    private void BeginProgressiveDownload()
    {
        WebClient client = new WebClient();
        client.AllowReadStreamBuffering = false;
        client.OpenReadCompleted += new OpenReadCompletedEventHandler(client_OpenReadCompleted);
        client.OpenReadAsync(new Uri("http://STREAMABLE RESOURCE HERE"));
    }

    void client_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
    {
        e.Result.ReadByte();
    }

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