使用 Base64 字符串在 MVC Webgrid 中下载问题

Question

我正在尝试在 MVC 网络网格中实现下载功能。这是演示代码。

型号

 public class Student
    {
        public string Name { get; set; }
        public string Address { get; set; }

        public string ByteArray { get; set; }

        public List<Student> StudentList { get; set; }

    }

查看

 @model Fileuploaddemo.Models.Student

   @{ var grid = new WebGrid(Model.StudentList);}

    @Html.LabelFor(model => model.Name)
    @Html.EditorFor(model => model.Name)

    @Html.LabelFor(model => model.Address)
    @Html.EditorFor(model => model.Address)

  @grid.GetHtml(            
                  htmlAttributes: new
                  {
                      id = "gridT1",
                      @calss = ""
                  },
    tableStyle: "webgrid-table",
    headerStyle: "webgrid-header",           
    columns: grid.Columns(
    grid.Column(columnName: "Name", header: "Name"),
    grid.Column(columnName: "Address", header: "Address") ))

控制器

 public ActionResult Index()
        {
            Student obj = new Student();
            obj.StudentList = new List<Student>();
            return View(obj);

        }
        [HttpPost]
        public ActionResult Index(Student obj, HttpPostedFileBase file1)
        {
            if (file1 != null)
            {
                MemoryStream target = new MemoryStream();
                file1.InputStream.CopyTo(target);
                byte[] data = target.ToArray();
                obj.ByteArray = Convert.ToBase64String(data);
            }

            obj.StudentList = new List<Student>();
            obj.StudentList.Add(obj);
            return View(obj);

        }

在这段代码中，我试图在 MVC Web 网格中显示学生详细信息以及文件下载选项。

但是在这里，我不知道如何下载base64string格式的文件。

请帮助我解决问题。

提前致谢。

Answer 1

您需要在WebGrid 中添加一个额外的列，其中会有一个名为“Download”的链接。此链接需要在控制器中调用下载操作并传递被点击学生的 base64 属性。下面是一个完整的工作示例，希望对您有所帮助：

控制器：

public class StudentController : Controller
{
    public ActionResult Index()
    {
        Student obj = new Student();
        byte[] bytes = System.IO.File.ReadAllBytes("F:\\test.txt");
        string ba = Convert.ToBase64String(bytes);

        var s1 = new Student { Name = "Student1", Address = "Address1", ByteArray = ba };
        var s2 = new Student { Name = "Student2", Address = "Address2", ByteArray = ba };
        var s3 = new Student { Name = "Student3", Address = "Address3", ByteArray = ba };

        obj.StudentList = new List<Student>() { s1, s2, s3 };
        return View(obj);
    }

    [HttpGet]
    public FileResult DownloadAction(string file)
    {
        byte[] fileBytes = Convert.FromBase64String(file);
        string fileName = "test.txt";
        return File(fileBytes, System.Net.Mime.MediaTypeNames.Application.Octet, fileName);
    }
}

查看：

@model Fileuploaddemo.Models.Student

@{ var grid = new WebGrid(Model.StudentList);}

@Html.LabelFor(model => model.Name)
@Html.EditorFor(model => model.Name)

@Html.LabelFor(model => model.Address)
@Html.EditorFor(model => model.Address)


@grid.GetHtml(
                  htmlAttributes: new
                  {
                      id = "gridT1",
                      @calss = ""
                  },
    tableStyle: "webgrid-table",
    headerStyle: "webgrid-header",
    columns: grid.Columns(
    grid.Column(columnName: "Name", header: "Name"),
    grid.Column(columnName: "Address", header: "Address"),
    grid.Column("Download", "Download", format: @<text>
        @Html.ActionLink("Download", "DownloadAction", "Student", new { file = item.ByteArray },null)
    </text>)
    ))