正如标题所说，我正在下载一个文件，它做得很好，除非我暂停下载进度。我使用以下后端代码下载我的文件，它可以安装>10Gb的文件（最重要的）。

public void TransmitFileAsync()
    {
        System.IO.Stream iStream = null;

        string fullPath = "D:\\backend-fileupload\\test.rar";

        string outFileName = "test.rar";

        // Buffer to read 10K bytes in chunk:
        byte[] buffer = new Byte[10485760];

        // Length of the file:
        int length;

        // Total bytes to read:
        long dataToRead;

        // Identify the file to download including its path.
        string filepath = fullPath;

        // Identify the file name.
        string filename = Path.GetFileName(filepath);

        try
        {
            // Open the file.
            iStream = new FileStream(filepath, FileMode.Open,
                        FileAccess.Read, FileShare.Read);

            // Total bytes to read:
            dataToRead = iStream.Length;

            Response.Clear();

            Response.ContentType = "application/octet-stream";

            Response.Headers.Add("Content-Disposition", "attachment; filename=" + outFileName );

            /*Response.Headers.Add("Content-Type", "application/octet-stream");*/

            Response.Headers.Add("Content-Length", iStream.Length.ToString());

            Response.Headers.AcceptRanges = "bytes";

            // Read the bytes.
            while (dataToRead > 0)
            {

                CancellationToken cancellationToken = HttpContext.RequestAborted;
               /* bool isPause = HttpContext.*/

                // Verify that the client is connected.
                // Read db auth ? or set in xml file and read
                if (!cancellationToken.IsCancellationRequested && true)
                {
                    // Read the data in buffer.
                    length = iStream.Read(buffer, 0, 10485760);

                    // Write the data to the current output stream.
                    Response.Body.Write(buffer, 0, length);

                    // Flush the data to the output.
                    Response.Body.Flush();

                    buffer = new Byte[10485760];

                    dataToRead = dataToRead - length;
                }
                else
                {
                    //prevent infinite loop if user disconnects
                    dataToRead = -1;
                }
            }
        }
        catch (Exception ex)
        {
            throw new ApplicationException(ex.Message);
        }
        finally
        {
            if (iStream != null)
            {
                //Close the file.
                iStream.Close();
            }
            Response.Body.Close();
            
        }
    }

字符串
前端：

fetch(requesturl, {
            method: 'POST',
            headers: {
                'Content-Type': "application/octet-stream",
                 
            },

        }).then(res  => {

            const readableStream = res.body;
            
            const name = "test.rar"

            const fileStream = streamSaver.createWriteStream(name, {
                size: Number(res.headers.get("Content-Length"))
            })
            
            if (window.WritableStream && readableStream?.pipeTo) {
                console.log('111done writing...')
                return readableStream.pipeTo(fileStream).then(() => {
                    console.log('done writing...')
                })
            }
            const reader = readableStream?.getReader();
            const writer = fileStream.getWriter();
            window.onunload = () => {
                fileStream.abort()
                // also possible to call abort on the writer you got from `getWriter()`
                writer.abort()
            }
            
            const pump: any = () =>
                reader?.read()
                    .then(res => res.done ? writer.close() : writer.write(res.value));
            pump();

型
问题是：
enter image description hereenter image description here的数据库
我只知道当我暂停下载文件时，后端代码仍然在while（）的循环中，我如何停止或暂停它来解决这个问题？