我创建的动态更新面板有问题。
问题是我想为我在服务器端创建的每个元素添加一个验证器,即 RequriedFieldValidator。以上工作正常。但是当我单击提交按钮时,它什么也不做。我可以在 htmlShellcode 中看到 span 元素显示错误,但它具有“style="visibility=hidden"。
我该如何解决这个问题?我也不确定我是否从一开始就做对了(对编程很陌生)。
标记:
<asp:Panel ID="UpdatepanelWrapper" CssClass="Updatepanelwrapper" runat="server">
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:PlaceHolder runat="server" ID="WholeWrapper">
<asp:PlaceHolder runat="server" ID="QuestionWrapper">
<asp:PlaceHolder runat="server" ID="LabelQuestion"><asp:PlaceHolder>
<asp:PlaceHolder runat="server" ID="Question"></asp:PlaceHolder>
</asp:PlaceHolder>
</asp:PlaceHolder>
</asp:PlaceHolder>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="btnAdd" EventName="Click" />
<asp:AsyncPostBackTrigger ControlID="btnDelete" EventName="Click" />
</Triggers>
</asp:UpdatePanel>
<asp:Panel ID="ButtonPanel" CssClass="ButtonPanel" runat="server">
<asp:ImageButton ID="btnDelete" runat="server" ImageUrl="~/Images/Deleteicon.png" CssClass="DeleteButton" OnClientClick="btnDelete_Click" />
<asp:ImageButton ID="btnAdd" runat="server" ImageUrl="~/Images/Addicon.png" CssClass="AddButton" OnClientClick="btnAddQuestion_Click" />
</asp:Panel>
</asp:Panel>
服务器代码:(重写方法 OnInit 是重要的)
public partial class _Default : Page
{
static int CountOfQuestions = 1;
private RequiredFieldValidator[] ArrRequiredFieldQuestion;
private Panel[] ArrWholePanel;
private Panel[] ArrQuestionPanel;
private Label[] ArrQuestionLabel;
private TextBox[] ArrQuestionBox;
protected void Page_Load(object sender, EventArgs e)
{
}
private void LoadControls()
{
Control myControl = GetPostBackControl(this.Page);
if (myControl != null)
{
if (myControl.ID.ToString() == "btnAdd") //Ändra till btnAddQuestion om en "button" ska användas
{
CountOfQuestions++;
}
if (myControl.ID.ToString() == "btnDelete")
{
CountOfQuestions--;
}
}
}
protected override void OnInit(EventArgs e)
{
base.OnInit(e);
if (!IsPostBack)
{
CountOfQuestions = 1;
}
LoadControls();
ArrRequiredFieldQuestion = new RequiredFieldValidator[CountOfQuestions];
ArrWholePanel = new Panel[CountOfQuestions];
ArrQuestionPanel = new Panel[CountOfQuestions];
ArrQuestionLabel = new Label[CountOfQuestions];
ArrQuestionBox = new TextBox[CountOfQuestions];
for (int i = 0; i < CountOfQuestions; i++)
{
RequiredFieldValidator ReqFieldQuestion = new RequiredFieldValidator();
PlaceHolder WholeWrapper = UpdatePanel1.FindControl("WholeWrapper") as PlaceHolder;
Panel WholePanel = new Panel();
Panel QuestionPanel = new Panel();
Panel CorrectAnswerPanel = new Panel();
Label QuestionLabel = new Label();
TextBox Question = new TextBox();
QuestionLabel.Text = "Write your question";
Question.TextMode = TextBoxMode.MultiLine;
Question.Width = 550;
Question.Height = 50;
WholePanel.ID = "WholePanel" + i.ToString();
QuestionPanel.ID = "QuestionPanel" + i.ToString();
Question.ID = "tbxQuestion" + i.ToString();
ReqFieldQuestion.ID = "Validate" + i.ToString();
ReqFieldQuestion.ControlToValidate = "tbxQuestion" + i.ToString();
ReqFieldQuestion.ValidationGroup = "QuestionGroup";
ReqFieldQuestion.ErrorMessage = "Error";
ReqFieldQuestion.Attributes.Add("runat", "server");
QuestionPanel.CssClass = "QuestionEntry";
QuestionPanel.Controls.Add(QuestionLabel);
QuestionPanel.Controls.Add(Question);
QuestionPanel.Controls.Add(ReqFieldQuestion);
WholeWrapper.Controls.Add(WholePanel);
WholePanel.Controls.Add(QuestionPanel);
ArrRequiredFieldQuestion[i] = ReqFieldQuestion;
ArrQuestionPanel[i] = QuestionPanel;
ArrQuestionLabel[i] = QuestionLabel;
ArrQuestionBox[i] = Question;
}
}
protected void btnAddQuestion_Click(object sender, EventArgs e)
{
//Handeld by Pre_init and LoadControls
}
protected void btnDelete_Click(object sender, EventArgs e)
{
//Handeld by Pre_init and LoadControls
}
public static Control GetPostBackControl(Page thePage)
{
Control postbackControlInstance = null;
if (postbackControlInstance == null)
{
for (int i = 0; i < thePage.Request.Form.Count; i++)
{
if ((thePage.Request.Form.Keys[i].EndsWith(".x")) || (thePage.Request.Form.Keys[i].EndsWith(".y")))
{
postbackControlInstance = thePage.FindControl(thePage.Request.Form.Keys[i].Substring(0, thePage.Request.Form.Keys[i].Length - 2));
return postbackControlInstance;
}
}
}
return postbackControlInstance;
}