我正在研究基于ASP.NET表单的应用程序。
我有一个中继器绑定到数据库。每行具有以下任何控件：
RadioButtonList
文本框
DropDownList
CheckBoxList
每行有以下验证控件之一：
RequiredFieldValidator
CustomValidator
我在中继器外面有一个按钮。当我单击“保存”按钮时，代码将遍历每个转发器项，读取所选数据并将其保存在数据库中。
我面临的问题是，当我单击“保存”按钮时，它给了我错误：
The ControlToValidate property of 'reqValidator' cannot be blank.
我确保只在第一次加载转发器，而不是在页面回发时加载。 此外，似乎未执行“保存”按钮中的代码。这是我的代码：
<cms:CMSUpdatePanel runat="server" ID="updatePanelCampaignQuestions">
<ContentTemplate>
<asp:Repeater ID="repeaterQuestions" runat="server" OnItemdatabound="repeaterQuestions_Itemdatabound">
<ItemTemplate>
<div class="repeater-container">
<asp:Label ID="lbQuestion" runat="server" Text='<%# Eval("Question") %>' />
<asp:Label ID="lbQuestionType" runat="server" Text='<%# Eval("QuestionType") %>' Style="display: inline; visibility: hidden" />
<asp:Label ID="lbAnswers" runat="server" Text='<%# Eval("Answers") %>' Style="display: inline; visibility: hidden" />
<asp:Label ID="lbArticleCampaignQuestionID" runat="server" Text='<%# Eval("ArticleCampaignQuestionID") %>' Style="display: inline; visibility: hidden" />
<div class="row validation-container">
<div class="col-md-12 col-lg-12">
<asp:TextBox ID="txtAnswer" CssClass="form-control" runat="server" TextMode="MultiLine" Rows="2" ValidationGroup="Campaign"></asp:TextBox>
<asp:RadioButtonList ID="rdAnswer" runat="server"></asp:RadioButtonList>
<asp:DropDownList ID="ddnAnswer" runat="server"></asp:DropDownList>
<asp:CheckBoxList ID="chkAnswer" CssClass="chkAnswer" runat="server"></asp:CheckBoxList>
<asp:RequiredFieldValidator ID="reqValidator" runat="server" Display="Dynamic" Style="color: #f00" />
<asp:CustomValidator ID="customValidator" runat="server" ClientValidationFunction="checkAnswer" Display="Dynamic" Style="color: #f00" />
<hr />
</div>
</div>
</div>
</ItemTemplate>
</asp:Repeater>
中继器OnItemdatabound的代码：
protected void repeaterQuestions_Itemdatabound(object sender,RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{
string questionType = (e.Item.FindControl("lbQuestionType") as Label).Text;
RequiredFieldValidator reqValidator = (RequiredFieldValidator)e.Item.FindControl("reqValidator");
CustomValidator customValidator = (CustomValidator)e.Item.FindControl("customValidator");
if (questionType.ToLower().Equals("text"))
{
e.Item.FindControl("txtAnswer").Visible = true;
e.Item.FindControl("rdAnswer").Visible = false;
e.Item.FindControl("chkAnswer").Visible = false;
e.Item.FindControl("ddnAnswer").Visible = false;
reqValidator.ControlToValidate = e.Item.FindControl("txtAnswer").ID;
reqValidator.ErrorMessage = "Please fill the answer";
e.Item.Controls.Remove(customValidator);
}
else if (questionType.ToLower().Equals("single selection"))
{
e.Item.FindControl("txtAnswer").Visible = false;
e.Item.FindControl("rdAnswer").Visible = true;
e.Item.FindControl("chkAnswer").Visible = false;
e.Item.FindControl("ddnAnswer").Visible = false;
string strAnswers = (e.Item.FindControl("lbAnswers") as Label).Text;
string[] answers = strAnswers.Split(new[] { "@@" },StringSplitOptions.None);
foreach(string answer in answers)
{
(e.Item.FindControl("rdAnswer") as RadioButtonList).Items.Add(answer);
}
reqValidator.ControlToValidate = e.Item.FindControl("rdAnswer").ID;
reqValidator.ErrorMessage = "Please select one";
e.Item.Controls.Remove(customValidator);
}
else if (questionType.ToLower().Equals("drop down"))
{
e.Item.FindControl("txtAnswer").Visible = false;
e.Item.FindControl("rdAnswer").Visible = false;
e.Item.FindControl("chkAnswer").Visible = false;
e.Item.FindControl("ddnAnswer").Visible = true;
string strAnswers = (e.Item.FindControl("lbAnswers") as Label).Text;
string[] answers = strAnswers.Split(new[] { "@@" },StringSplitOptions.None);
(e.Item.FindControl("ddnAnswer") as DropDownList).Items.Add(new ListItem("- Please Select -","0"));
foreach (string answer in answers)
{
(e.Item.FindControl("ddnAnswer") as DropDownList).Items.Add(answer);
}
reqValidator.InitialValue = "0";
reqValidator.ControlToValidate = e.Item.FindControl("ddnAnswer").ID;
reqValidator.ErrorMessage = "Please select one";
e.Item.Controls.Remove(customValidator);
}
else if (questionType.ToLower().Equals("multiple selection"))
{
e.Item.FindControl("txtAnswer").Visible = false;
e.Item.FindControl("rdAnswer").Visible = false;
e.Item.FindControl("chkAnswer").Visible = true;
e.Item.FindControl("ddnAnswer").Visible = false;
string strAnswers = (e.Item.FindControl("lbAnswers") as Label).Text;
string[] answers = strAnswers.Split(new[] { "@@" },StringSplitOptions.None);
foreach (string answer in answers)
{
(e.Item.FindControl("chkAnswer") as CheckBoxList).Items.Add(answer);
}
e.Item.Controls.Remove(reqValidator);
customValidator.ErrorMessage = "Please select at least one";
}
}
}
保存按钮的代码：
private void SaveAnswer()
{
int userID = GetUserID();
int campaignID = getcampaignID();
foreach (RepeaterItem item in repeaterQuestions.Items)
{
string answer = "";
string questionType = (item.FindControl("lbQuestionType") as Label).Text;
int articleCampaignQuestionID = int.Parse((item.FindControl("lbArticleCampaignQuestionID") as Label).Text);
if (questionType.ToLower().Equals("text"))
{
answer = (item.FindControl("txtAnswer") as TextBox).Text;
}
else if (questionType.ToLower().Equals("single selection"))
{
answer = (item.FindControl("rdAnswer") as RadioButtonList).SelectedItem.Text;
}
else if (questionType.ToLower().Equals("drop down"))
{
answer = (item.FindControl("ddnAnswer") as DropDownList).SelectedItem.Text;
}
else if (questionType.ToLower().Equals("multiple selection"))
{
CheckBoxList answerList = (item.FindControl("chkAnswer") as CheckBoxList);
foreach (ListItem checkItem in answerList.Items)
{
if (checkItem.Selected)
{
answer += checkItem.Text + "@@";
}
}
if (answer.EndsWith("@@"))
answer = answer.Substring(0,answer.Length - 2);
}
// save value of answer to database
}
我对此坚持了很长时间。除上述页面外，页面上没有其他例外。
修改
页面回发的流程是什么？
点击btnSaveAnswer，执行按钮代码，重新加载转发器
或
点击btnSaveAnswer，转发器被重新加载，按钮代码执行
如果我将中继器绑定与：
if(!Page.IsPostBack)
我得到了必填字段验证器错误
和
如果我没有在 if 以上使用，则无法从中继器的控件中读取值