1. 使用Range头分块传输视频文件，这可以避免加载整个文件到内存中。以下是一个基本的示例：

[HttpGet] public IActionResult GetVideo(string filename) { string path = Path.Combine(_env.WebRootPath, "videos", filename); var stream = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read); return new FileStreamResult(stream, "video/mp4"); }

2. 使用外部库来处理视频文件，例如ffmpeg。使用ffmpeg可以将视频文件分成多个部分，并将它们流式传输到浏览器，从而避免内存溢出的问题。以下是一个基本的示例：

[HttpGet] public IActionResult GetVideo(string filename) { string path = Path.Combine(_env.WebRootPath, "videos", filename);

var ext = Path.GetExtension(filename).ToLowerInvariant();
var mime = ext switch
{
    ".mp4" => "video/mp4",
    ".mkv" => "video/x-matroska",
    ".webm" => "video/webm",
    _ => "application/octet-stream"
};

var cmd = $"-i \"{path}\" -movflags frag_keyframe+empty_moov -f mp4 -frag_size 4096 -";
var ffmpeg = new ProcessStartInfo("ffmpeg", cmd)
{
    RedirectStandardOutput = true,
    UseShellExecute = false,
};

Response.RegisterForDispose(Process.Start(ffmpeg));

Response.Headers.Add("Accept-Ranges", "bytes");

return File(Response.Body, mime);

}