尝试从复选框中检索数据时出现问题

Question

我正在尝试执行下面的代码以在复选框中列出选择项

到邮件正文

 Dim CheckedValues As String
                For Each item In txt_panview0_ddinput1.Items
                    If item.checked Then
                        checkedValues = checkedValues & item.selectedValue

                    End If
                Next
                If Not String.IsNullOrEmpty(checkedValues) Then
                    checkedValues = checkedValues.Substring(1)
                End If


                tempCollector = tempCollector + "<br>" + "Area Name" + ": " + checkedValues

但我收到以下错误..

System.MissingMemberException: Public member 'checked' on type 'ListItem' not found. 
at Microsoft.VisualBasic.CompilerServices.Symbols.Container.GetMembers(String& MemberName, 
Boolean ReportErrors) at Microsoft.VisualBasic.CompilerServices.NewLateBinding.
LateGet(Object Instance, Type Type, String MemberName, Object[] Arguments, String[] ArgumentNames, Type[] 
TypeArguments, Boolean[] CopyBack) at WebApplication1._Default.collectEmailBodyText() 
in C:\UseFormCode\UseFormEnhWorking\Default.aspx.vb:line 271 

请帮忙

Answer 1

在检查是否已检查之前将迭代中的每个项目类型转换为 CheckBox：

For Each item In txt_panview0_ddinput1.Items
     dim c as CheckBox = Ctype(item.Value, CheckBox)
     If c.checked Then
         checkedValues = checkedValues & item.selectedValue
    End If
Next

要启用多个值的选择，请将ListBox 的SelectionMode 属性设置为Multiple：

<asp:ListBox ID="ListBox1" runat="server" SelectionMode="Multiple"></asp:ListBox>

然后要遍历选定的值，请使用以下命令：

For Each item as ListItem In txt_panview0_ddinput1.Items
         If item.Selected Then
             CheckedValues = CheckedValues & item.Value
        End If
Next

PS 我对 VB.Net 语法有点生疏，所以我的代码可能在语法上并不完美