在浏览器c#中显示文件

我有这样的代码:

   public void OpenFile(string fileName)
        {
            var url = Path.Combine(Server.MapPath("~/App_Data/uploads"), fileName);
            using (var fileStream =  new FileStream(url, FileMode.Open))
            {
                byte[] bytes = new byte[fileStream.Length];
                int numBytesToRead = (int)fileStream.Length;
                int numBytesRead = 0;
                fileStream.Read(bytes,numBytesRead, numBytesToRead);              
            }
        }

代码运行正常，但我想在浏览器中显示文件，我在click上执行这个方法在文件名中，参数运行良好，我还需要哪段代码来在浏览器中显示文件?大多数文件都是。doc和。pdf。我如何在浏览器中显示文档??

public ActionResult OpenFile(string fileName)
{
   var pathToTheFile = Path.Combine(Server.MapPath("~/App_Data/uploads"), fileName);
   var fileStream = new FileStream(pathToTheFile,
                                    FileMode.Open,
                                    FileAccess.Read
                                );
   return  new FileStreamResult(fileStream,  MimeMapping.GetMimeMapping(fileName));    
}