Question

我在Asp.Net开发网站，其中一个网页要求用户上传文件。客户端希望将文件大小限制设置为最大5MB。我使用以下代码在web.config中设置了限制;

 <system.webServer>
<security>
  <requestFiltering>
    <requestLimits maxAllowedContentLength="5242880" /> <!--5MB-->
  </requestFiltering>
</security> </system.webServer>

检查文件扩展名并向用户显示错误消息的页面的C＃代码具有以下代码。

string[] validFileTypes = { "doc", "docx", "xls", "pdf" };
    string ext = System.IO.Path.GetExtension(FileUpload1.PostedFile.FileName);
    bool isValidFile = false;

    for (int i = 0; i < validFileTypes.Length; i++)
    {
        if (ext == "." + validFileTypes[i])
        {
            isValidFile = true;
            break;
        }
    }
        if (!isValidFile)
        {
            DisplayMessage.Visible = true;
            DisplayMessage.Text = "Invalid file or file size has exceeded it max limit of 5MB. Please upload a file with one of the following extension; <br /><br />" +
            string.Join(", ", validFileTypes) + "or a smaller file";
    }
    else
    {
        string targetFolder = HttpContext.Current.Server.MapPath("~/App_Data/");
        string targetPath = Path.Combine(targetFolder, FileUpload1.FileName);
        FileUpload1.SaveAs(targetPath);

        DisplayMessage.Visible = true;
        DisplayMessage.Text = "File uploaded successfully.";
    }

我遇到的问题是，当我尝试上传大于5MB的文件而不是显示错误消息的页面时，它会向我发送stack trace enter image description here

有人可以告诉我哪里出错了。非常感谢提前！

Answer 1

在web.config文件中写这个

<system.web>
<httpRuntime executionTimeout="9999" maxRequestLength="5242880"/>
</system.web>

//使用label（id = Label1）控件来显示错误。

if (FileUpload1.HasFile)
{
   if (FileUpload1.PostedFile.ContentLength < 5242880)
     {
        /* your code */
      }
  else
    {
     Label1.Text = "File size exceeds maximum limit 5 MB.";
    }
}

Answer 2

从this SO answer

尝试以下解决方案

<configuration>
  <system.web>
    <httpRuntime maxRequestLength="xxx" />
  </system.web>
</configuration>

此外，如果您愿意，可以进行验证client side。

Answer 3

fileId =文件标记的ID fileMsg = Div的Id，它位于文件输入下面，如

<html>
 <input type="file" id="fileId" name="file" onchange="uploadFile()">
 <div id="fileMsg"></div>



<script>
function uploadFile() {
    var filename = $('#fileId').val().split('.').pop().toLowerCase();
    var fileInput =  document.getElementById('fileId');
    if (filename == 'doc' || filename == 'xls' || filename == 'docx' || filename == 'pdf') {
        var filesize=(fileInput.files[0].size);
        if (filesize > 5000000) {
            $('#fileMsg').html('Invalid File Size');
        } else {
            $('#fileMsg').html('');
        }
    } else {
        $('#fileMsg').html('Invalid File Type');
    }
}
</script>
</html>

如果文件大小超过最大限制，则显示消息

3 个答案: