我正在尝试检查文件扩展名，但出于某种原因， class ChannelsTVC: UITableViewController {
var channels = [String]() {
didSet {
tableView?.reloadData()
}
} // channels
var myMobChatTVC = MOBChatTVC()
override func viewDidLoad() {
super.viewDidLoad()
channels = myMobChatTVC.chatArray
} // viewDidLoad
} // ChannelsTVC
始终为false。
Valid我总是得到 <asp:FileUpload ID="LogoUpload" CssClass="form-control" runat="server" /><asp:Button ID="BtnLogoUpload" runat="server" CssClass="btn btn-primary" Text="Upload" />
<asp:Label ID="lblLUploadMessage" runat="server" ForeColor="Red" ></asp:Label>
Protected Sub BtnLogoUpload_Click(sender As Object, e As EventArgs) Handles BtnLogoUpload.Click
If (LogoUpload.HasFile) Then
Dim fileExtension As String = Path.GetExtension(LogoUpload.FileName)
Dim extension = New String() {"jpg", "png", "gif"}
Dim Valid As Boolean = False
For Each ext As String In extension
If ext.Equals(fileExtension) Then
Valid = True
End If
Next
If Valid = True Then
LogoUpload.SaveAs(Server.MapPath(String.Format("{0}/{1}/{2}", "~/CW/uploads", register_username.Text, "logo") + LogoUpload.FileName)) ' Save file in directory
lblLUploadMessage.Text = "File Uploaded Successfully"
lblLUploadMessage.ForeColor = System.Drawing.Color.Green
Else
lblLUploadMessage.Text = "File extension is not valid"
End If
End If
End Sub
答案 0 :(得分：1)
方法Path.GetExtension有一个问题。如MSDN documentation中所述，此方法的返回值为：
指定路径的扩展名（包括句号＆＃34;。＆＃34;）或 null，或String.Empty。
这里的重要部分是 （包括句号＆＃34;。＆＃34;） 。这意味着如果您上传bmp文件，方法Path.GetExtension不会返回bmp，而是.bmp。
因此，为了使其工作，您必须使用具有句点的扩展名：
Dim extension = New String() {".jpg", ".png", ".gif"}
或从延期开始修剪期间：
Dim fileExtension As String = Path.GetExtension(LogoUpload.FileName)
fileExtension = fileExtension.TrimStart("."c)