C#：MVC返回FileResult文件对象，并在VIEW视图中下载

FileResult是一个抽象类，有3个继承子类：FilePathResul、FileContentResult、FileStreamResult，表示一个文件对象，三者区别在于，FilePath 通过路径传送文件到客户端，FileContent 通过二进制数据的方式，而FileStream 是通过Stream(流)的方式来传送。Controller为这三个文件结果类型提供了一个名为File的重载方法。

using System.Web.Mvc; using System.IO;

namespace FileResultTest.Controllers { public class FileResultTest: Controller{

    public FilePathResult DownloadFileByPath() {
        //文件路径必须是绝对路径。
        string filePath = Server.MapPath("~/Content/test.pdf");
        return File(filePath, "application/x-zip-compressed","test.pdf");
    }

    public FileContentResult DownloadFileByContent() {
        string filePath = Server.MapPath("~/Content/test.pdf");
        FileStream fs = new FileStream(filePath, FileMode.Open);
        byte[] bytes = new byte[fs.Length];
        fs.Read(bytes, 0, bytes.Length);
        fs.Close();
        return File(bytes, "application/x-zip-compressed","test.pdf");
    }

    public FileStreamResult DownloadFileByStream() {
        string filePath = Server.MapPath("~/Content/test.pdf");
        Stream stream = new FileStream(filePath, FileMode.Open);
        return File(stream,"application/x-zip-compressed","test.pdf");            
    }
}