在 html 视频上当前播放位置不会改变

Question

我有一个位于 mvc3 razor 视图上的 html5 视频播放器。我的视频播放得很好，但奇怪的是我似乎无法使用

video

元素的滑块控件更改播放位置（时间）。我用鼠标改变播放位置，但它只是从离开的地方继续。

我想我应该有一些额外的 javascript 来处理视频搜索，但这只是废话不是吗？我在这里缺少什么？

下面是我的html。

<video id="presentedFile" width="780" height="510" controls>
    <source src="/Folder/GetVideoStream?videoId=3" type="video/mp4">
</video>

编辑：我发现当我将源代码作为我的 mvc 控制器的操作链接时，就会出现此问题。如果我直接从文件中获取文件，它就会按我的预期工作。所以我的控制器肯定有问题。

public FileResult GetVideoStream( string videoId )
{
    /// create my stream
    return File(myStream, MimeMapping.GetMimeMapping(myVideo));
}

Answer 1

从this答案开始，我设法克服了这个问题。认为是响应中缺少 http 标头

accept-ranges

和

content-range

导致视频无法拖动。

只是为了简化上面链接中提到的解决方案，他们使用了 http 处理程序来解决问题。但我想声明的是，使用/实现 http 处理程序不是所需解决方案的一部分。解决方案是您必须在响应中添加必要的标头，如下所示：

public FileResult GetVideoStream( string videoId )
{
    /// create the stream

    /// if request contains range details
    if ( !String.IsNullOrEmpty(HttpContext.Request.ServerVariables["HTTP_RANGE"]) )
        SetHeadersForRangedRequests(stream, HttpContext);

    return File(myStream, MimeMapping.GetMimeMapping(myVideo));
}

以下方法引用自上面的链接，我只是删除了

using

周围的

StreamReader

，因为我需要在操作完成后保持流打开。

void SetHeadersForRangedRequests ( Stream stream, HttpContextBase context )
{
    long size, start, end, length, fp = 0;
    StreamReader reader = new StreamReader(stream);

    size = reader.BaseStream.Length;
    start = 0;
    end = size - 1;
    length = size;

    context.Response.AddHeader("Accept-Ranges", "0-" + size);
        
    if ( !String.IsNullOrEmpty(context.Request.ServerVariables["HTTP_RANGE"]) )
    {
        long anotherStart = start;
        long anotherEnd = end;
        string[] arr_split = context.Request.ServerVariables["HTTP_RANGE"].Split(new char[] { Convert.ToChar("=") });
        string range = arr_split[1];

        // Make sure the client hasn't sent us a multibyte range
        if ( range.IndexOf(",") > -1 )
        {
            // (?) Shoud this be issued here, or should the first
            // range be used? Or should the header be ignored and
            // we output the whole content?
            context.Response.AddHeader("Content-Range", "bytes " + start + "-" + end + "/" + size);
            throw new HttpException(416, "Requested Range Not Satisfiable");
        }

        // If the range starts with an '-' we start from the beginning
        // If not, we forward the file pointer
        // And make sure to get the end byte if spesified
        if ( range.StartsWith("-") )
        {
            // The n-number of the last bytes is requested
            anotherStart = size - Convert.ToInt64(range.Substring(1));
        }
        else
        {
            arr_split = range.Split(new char[] { Convert.ToChar("-") });
            anotherStart = Convert.ToInt64(arr_split[0]);
            long temp = 0;
            anotherEnd = ( arr_split.Length > 1 && Int64.TryParse(arr_split[1].ToString(), out temp) ) ? Convert.ToInt64(arr_split[1]) : size;
        }
        /* Check the range and make sure it's treated according to the specs.
            * http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
            */
        // End bytes can not be larger than $end.
        anotherEnd = ( anotherEnd > end ) ? end : anotherEnd;
        // Validate the requested range and return an error if it's not correct.
        if ( anotherStart > anotherEnd || anotherStart > size - 1 || anotherEnd >= size )
        {

            context.Response.AddHeader("Content-Range", "bytes " + start + "-" + end + "/" + size);
            throw new HttpException(416, "Requested Range Not Satisfiable");
        }
        start = anotherStart;
        end = anotherEnd;

        length = end - start + 1; // Calculate new content length
        fp = reader.BaseStream.Seek(start, SeekOrigin.Begin);
        context.Response.StatusCode = 206;
    }

    // Notify the client the byte range we'll be outputting
    context.Response.AddHeader("Content-Range", "bytes " + start + "-" + end + "/" + size);
    context.Response.AddHeader("Content-Length", length.ToString());
}