If _values.Count > 0 Then For Each key As String In _values.Keys Dim item As ListItem = New ListItem item.Value = key item.Text = _values(key) _DropDownList.Items.Add(item) Next End If ''''''''如果只有一个可选内容 If _DropDownList.Items.Count = 1 Then Dim item As ListItem = New ListItem item.Value = "" item.Text = " " _DropDownList.Items.Add(item) _DropDownList.SelectedIndex = 1 End If _DropDownList.RenderControl(Output)