HttpClient下载文件内存不足错误

本文关键字：错误 内存不足 文件 下载 HttpClient | 更新日期: 2023-09-27 17:58:46

你好，我将此代码用于文件下载功能，但由于我的文件大小较大，收到了OutOfMemory异常。

private async void DownloadFile()
    {
        string url = "http://download.microsoft.com/download/0/A/F/0AFB5316-3062-494A-AB78-7FB0D4461357/Windows_Win7SP1.7601.17514.101119-1850.AMD64CHK.Symbols.msi";
        string filename = "test.msi";
        HttpClientHandler aHandler = new HttpClientHandler();
        aHandler.ClientCertificateOptions = ClientCertificateOption.Automatic;
        HttpClient aClient = new HttpClient(aHandler);
        aClient.DefaultRequestHeaders.ExpectContinue = false;
        HttpResponseMessage response = await aClient.GetAsync(url, HttpCompletionOption.ResponseHeadersRead); // Important! ResponseHeadersRead.
        var imageFile = await ApplicationData.Current.LocalFolder.CreateFileAsync(filename, CreationCollisionOption.ReplaceExisting);
        var fs = await imageFile.OpenAsync(FileAccessMode.ReadWrite);
        Stream stream = await response.Content.ReadAsStreamAsync();
        IInputStream inputStream = stream.AsInputStream();
        ulong totalBytesRead = 0;
        while (true)
        {
            // Read from the web.
            IBuffer buffer = new Windows.Storage.Streams.Buffer(1024);
            buffer = await inputStream.ReadAsync(
                buffer,
                buffer.Capacity,
                InputStreamOptions.None);
            if (buffer.Length == 0)
            {
                // There is nothing else to read.
                break;
            }
            // Report progress.
            totalBytesRead += buffer.Length;
            System.Diagnostics.Debug.WriteLine("Bytes read: {0}", totalBytesRead);
            // Write to file.
            await fs.WriteAsync(buffer);
            buffer = null;
        }
        inputStream.Dispose();
        fs.Dispose();
    }

PS。我使用httpclient下载，但Windows手机后台传输有100MB的wifi限制。

HttpClient下载文件内存不足错误

我在去年编写的一些不同的代码中遇到了同样的问题，尽管那是POST而不是GET。不幸的是，我没有找到绕过它的方法，所以我直接使用WebRequest。以下是修复的片段：

// HttpWebRequest is used here instead of HttpClient as there is no support
// in HttpClient to not buffer uploaded streams, which for our purposes
// causes an OutOfMemoryException to occur.
HttpWebRequest request = WebRequest.Create(ServiceUri.ToString() + requestUri) as HttpWebRequest;
request.ContentLength = content.Length;
request.ContentType = "application/octet-stream";
request.Method = "POST";
request.AllowWriteStreamBuffering = false;  // Prevents OutOfMemoryException

我认为您的解决方案是在使用HttpClient下载时以某种方式禁用缓冲。

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