//将虚拟路径转化为文件的路径然后最后转化为文件流

public ActionResult SaveImage(string path)

{

var url =System.Web.HttpContext.Current.Request.PhysicalApplicationPath + path;

FileStream fs = new FileStream(url, FileMode.Open, FileAccess.Read); //将图片以文件流的形式进行保存

BinaryReader br = new BinaryReader(fs);

byte[] imgBytesIn = br.ReadBytes((int)fs.Length); //将流读入到字节数组中

Encoding myEncoding = Encoding.GetEncoding("utf-8");

string stImageByte = Convert.ToBase64String(imgBytesIn);

return Json(stImageByte);

}