C# 检查框列表的编程创建的CustomValidator ServerValidate事件有问题

我正在尝试使用C为asp.net CheckBoxList动态创建CustomValidator。我似乎很好地完成了验证程序的创建，但是ServerValidate给我带来了一些麻烦。我根据我手动创建的一个CustomValidator对其进行建模，该程序运行良好，因此我不太确定需要做哪些不同的工作

这里是手动CustomValidator，它可以完美地工作。这是我的模型：

<asp:CustomValidator ID="CustomV_JobPositions" runat="server" 
     ErrorMessage="Please select at least one job position." 
     OnServerValidate="CustomV_JobPositions_ServerValidate" 
     ValidationGroup="JobPositions" Display="Dynamic" ForeColor="Red">
</asp:CustomValidator>
<asp:CheckBoxList ID="CBL_JobPositions" runat="server" 
     DataSourceID="JobPositionsEntity" DataTextField="JobPosition1" 
     DataValueField="JobPositionID" RepeatColumns="3" Width="100%" 
     OnSelectedIndexChanged="CBL_JobPositions_SelectedIndexChanged" 
     AutoPostBack="True" ValidationGroup="JobPositions">
</asp:CheckBoxList>

因此，以上所有操作都很好。 然后我尝试以动态/编程方式复制它：

public CustomValidator CreateDynamicCustomCheckBoxListValidator(string ControlToValidate, string ValidationGroup)
{

    CustomValidator CV = new CustomValidator();                  // Set up a new CustomValidator
    CV.ID = "CustomV_" + ControlToValidate;                      // Set Validator ID with the name of desired control
    CV.ErrorMessage = "At Least One Selection Required";         // ... then set the error message to "at least one selection required"
    CV.ForeColor = System.Drawing.Color.Red;                     // Make the validator error display red
    CV.ValidationGroup = ValidationGroup;                        // Assign this validator to a group
    CV.Display = ValidatorDisplay.Dynamic;                       // Make the validator display dynamically
    CV.ServerValidate += new ServerValidateEventHandler(CustomV_CheckBoxList_ServerValidate);
    return CV;                                                   // Return the completed validator that was just created
}

private void CustomV_CheckBoxList_ServerValidate(object source, ServerValidateEventArgs args)
{
    args.IsValid = false;                        // Assume initially that nothing is checked
    CheckBoxList CBL = (CheckBoxList)source;
    foreach (ListItem item in CBL.Items)         // Loop through each list item in the checkbox
    {
        if (item.Selected == true)               // If at least one item is checked...
        { args.IsValid = true; }                 // ... then mark the whole list as valid...
    }
}

它似乎毫不费力地创建了CustomValidator，但在实际执行验证时，它会抛出以下错误：

无法将“System.Web.UI.WebControl.CustomValidator”类型的对象强制转换为“System.Web.UI.WebControl.CheckBoxList”类型

唯一的问题是，我需要循环检查复选框列表，如果没有该转换，我无法对其进行编程，以便对源代码执行任何操作。例如，下面的代码给了我这个错误：foreach语句无法对“object”类型的变量进行操作，因为“object”不包含“GetEnumerator”的公共定义

private void CustomV_CheckBoxList_ServerValidate(object source, ServerValidateEventArgs args)
{
    args.IsValid = false;                       // Assume initially that nothing is checked
    //CheckBoxList CBL = (CheckBoxList)source;
    foreach (ListItem item in source)           // Loop through each list item in the checkbox
    {
        if (item.Selected == true)              // If at least one item is checked...
        { args.IsValid = true; }                // ... then mark the whole list as valid...
    }
}

---

有没有关于如何让它工作的想法/我做错了什么？

这是一篇老文章，但我遇到了一个类似的问题，所以我想我会发布我是如何绕过这个问题的

创建从CustomValidator继承的对象，并为其提供名为ControlId的属性：

公共类CustomValidatorWithValidatedControlAttributes:CustomValidator { 公共字符串ControlId{get；set；} }

动态创建CustomValidatorWithValidatedControlAttributes的实例，提供ControlId属性：

var customValidator=新的CustomValidatorWithValidatedControlAttributes { ID=string.ConcatTheControl.ID，_customFieldValidator， EnableClientScript=false， Display=ValidatorDisplay.Dynamic， ErrorMessage=必需， CssClass=错误， ControlId=control.ID }; customValidator.ServerValidate+=customValidator\u ServerValidate

然后在ServerValidate方法中将对象强制转换回CustomValidatorWithValidatedControlAttributes类，并从ControlId属性访问复选框，然后检查是否选中该复选框：

    void customValidator_ServerValidate(object source, ServerValidateEventArgs args)
    {
        var customValidator = source as CustomValidatorWithValidatedControlAttributes;
        if (customValidator != null)
        {
            var checkBox = FindControl(customValidator.ControlId) as CheckBox;
            if (checkBox != null)
            {
                args.IsValid = checkBox.Checked;
            }
        }

        args.IsValid = false;
    }

    void customValidator_ServerValidate(object source, ServerValidateEventArgs args)
    {
        var customValidator = source as CustomValidatorWithValidatedControlAttributes;
        if (customValidator != null)
        {
            var checkBox = FindControl(customValidator.ControlId) as CheckBox;
            if (checkBox != null)
            {
                args.IsValid = checkBox.Checked;
            }
        }

        args.IsValid = false;
    }