如何将文件和文件路径从 C# 控制器发送到视图

Posted 2023-04-01

【中文标题】如何将文件和文件路径从 C# 控制器发送到视图

【英文标题】：How send File and File Path from C# Controller to the View

【发布时间】：2022-01-16 14:46:44

【问题描述】：

我正在将文件和文件路径从控制器发送到 MVC 视图：

这是我的控制器：

 public ActionResult Help()


    var releaseNoteFiles = Directory.GetFiles(Server.MapPath("~/Content/ReleaseNotes"));

    List<string> month = new List<string>();
    foreach (var releaseNoteFile in releaseNoteFiles)
    
        month.Add(new Regex("([^A-Z]*)([a-zA-Z]*)").Match(Path.GetFileNameWithoutExtension(releaseNoteFile).Split('.').Last()).Groups[2].Value);
    
    ViewBag.releaseNoteFilesmonth = month;
    ViewBag.releaseNoteFiles = releaseNoteFiles;

    return View();

这是在视图中显示的方式：

   @foreach (var item in ViewBag.releaseNoteFilesmonth)
                      
           <a href="(ViewBag.releaseNoteFiles as string[]).Where(x => x.Contains(item)).FirstOrDefault()"> @item</a>
            <br />
        

这是我期待的输出：

OCT - (Link to the file)
NOV - (Link to the file)
Dec - (Link to the file)

当我像这样对路径进行硬编码时，它正在工作：

 href="~/Content/ReleaseNotes/Release Notes 1.104.0_August102021.pdf"

但是当我尝试动态访问它时不确定如何写入文件的路径，这一行无法正常工作：

 href="(ViewBag.releaseNoteFiles as string[]).Where(x => x.Contains(item)).FirstOrDefault()">

【参考方案1】：

Server.MapPath返回驱动器的文件路径，例如E://projectfolder/content/...并且不要在url中使用这个地址。

将此行添加到您的代码并设置为ViewBag.releaseNoteFiles = filePath;

List<string> filePath = releaseNoteFiles.Select(a => string.Format("0/1", "~/Content/ReleaseNotes", Path.GetFileNameWithoutExtension(a))).ToList();

完整代码

public ActionResult Help()


    var releaseNoteFiles = Directory.GetFiles(Server.MapPath("~/Content/ReleaseNotes"));

    List<string> month = new List<string>();
    List<string> filePath = releaseNoteFiles.Select(a => string.Format("0/1", "~/Content/ReleaseNotes", Path.GetFileNameWithoutExtension(a))).ToList();
    
    foreach (var releaseNoteFile in releaseNoteFiles)
    
        month.Add(new Regex("([^A-Z]*)([a-zA-Z]*)").Match(Path.GetFileNameWithoutExtension(releaseNoteFile).Split('.').Last()).Groups[2].Value);
    
    ViewBag.releaseNoteFilesmonth = month;
    ViewBag.releaseNoteFiles = filePath;

    return View();

或使用：

public ActionResult Help()


    var releaseNoteFiles = Directory.GetFiles(Server.MapPath("~/Content/ReleaseNotes"));

    ViewBag.releaseNoteFilesmonth = releaseNoteFiles
                          .Select(a => new Regex("([^A-Z]*)([a-zA-Z]*)").Match(Path.GetFileNameWithoutExtension(a).Split('.').Last()).Groups[2].Value).ToList();
    ViewBag.releaseNoteFiles = releaseNoteFiles.Select(a => string.Format("0/1", "~/Content/ReleaseNotes", Path.GetFileNameWithoutExtension(a))).ToList();
    return View();

并将视图更改为：

@foreach (var item in ViewBag.releaseNoteFilesmonth)
  
    string url = string.Empty;
    if(ViewBag.releaseNoteFiles != null && !string.IsNullOrEmpty(item))
    
        url = (ViewBag.releaseNoteFiles as string[]).Where(x => x.Contains(item)).FirstOrDefault();
    
    
    <a href="@url"> @item</a>
    <br />

【讨论】：

谢谢，我在控制器中添加了这段代码，但是视图中的代码不起作用，我应该在 href=""

修改你的视图代码。我把视图代码放在响应中

谢谢@Meysam Asadi，收到此错误：值不能为空。参数名：source on the string url = .... in view

通常不应该给出这样的错误。 ViewBag.releaseNoteFiles 可能为空

它在我调试时有价值