reference - 你调用的对象是空的 -

Question

object reference not set to an instance of an object--

请帮我解决这个错误。我的语法有错误吗？

string filename = Path.GetFileName(FileUpload1.PostedFile.FileName);
FileUpload1.SaveAs(Server.MapPath("~/Uploads/") + filename);

我在第一行有问题

Answer 1

好吧，您没有提到任何语言和平台。但似乎你正在使用 asp.net 这里是 VB 代码来帮助你。

 Sub SubmitButton_Click(Source As Object, e As EventArgs)
   If Not (File1.PostedFile Is Nothing) Then
      Try
         File1.PostedFile.SaveAs("C:\Uploads\uploadedfile.txt")
         Span1.InnerHtml = "Upload Successful!"
      Catch ex As Exception
           ex.ToString()
      End Try
   End If
End Sub