2

当我单击按钮并将控件添加到 UpdatePanel 内的占位符时，一切都很好，除非我非常快速地单击几次然后收到如下错误消息：

'Sys.WebForms.PageRequestManagerServerErrorException: Sys.WebForms.PageRequestManagerServerErrorException: Multiple controls with the same ID 'VehicleRegistrationEnhancedTextBox3_Label' were found. FindControl requires that controls have unique IDs.' when calling method: [nsIDOMEventListener::handleEvent]
[Break On This Error]

我在隐藏字段中保存了一个整数，以创建唯一的 Id，当我点击非常快时，该方法执行了几次，但计数值尚未更新。我尝试使用 C# lock 关键字，但什么也没做。

代码如下：

protected void AddVehicleButton_Click(object sender, EventArgs e)
        {
            lock (this)
            {
                int count = Convert.ToInt32(VehicleRegistrationCountHiddenField.Value);

                var TBId = "VehicleRegistrationEnhancedTextBox" + count;
                IList<Panel> oldPanels = (IList<Panel>)Session["VehiclePanels"] ?? new List<Panel>();

                //Seperator
                Literal hr = new Literal { Text = "<hr/>" };

                //RemoveSpan
                Literal span = new Literal() { Text = "<span class=\"RemoveVehicleRegistration\">X</span>" };

                //Crop
                Control uc = LoadControl("~/Controls/ImageUploadAndCrop/ImageUploadAndCrop.ascx");
                uc.ID = "VehicleRegistrationImageUploadAndCrop" + count;

                //Vehicle Registration
                Label vehicleRegistration = new Label
                {
                    ID = TBId + "_Label",
                    AssociatedControlID = TBId,
                    Text = "Vehicle Registration:"
                };
                EnhancedTextBox vehicleTypeTextBox = new EnhancedTextBox
                {
                    ID = TBId,
                    Required = true,
                    RequiredErrorText = "Vehicle Registration is a required field."
                };

                //Add new controls to the form
                Panel newPanel = new Panel();

                newPanel.Controls.Add(hr);
                newPanel.Controls.Add(span);
                newPanel.Controls.Add(vehicleRegistration);
                newPanel.Controls.Add(uc);
                newPanel.Controls.Add(vehicleTypeTextBox);

                AddVehiclePlaceholder.Controls.Add(newPanel);

                //Increment the ID count
                count++;
                VehicleRegistrationCountHiddenField.Value = count.ToString();

                //Save the panel to the Session.
                oldPanels.Add(newPanel);
                Session["VehiclePanels"] = oldPanels;

                //Go back to the same wizard step.
                ShowStep2HiddenField.Value = "true";
                ShowStep3HiddenField.Value = "false";
            }
        }
4

2 回答 2

3

问题是你用相同的请求踢了几个回发，然后最后一个响应是更新你的更新面板 div，导致你的问题。一种可能的解决方案是包含一些 javascript 以禁用单击按钮。 

<asp:Button ID="myUpdatePanelPostBackButton" runat="server" OnClientClick="this.disabled=true; return true;" Text="Submit" />

假设您的按钮位于 UpdatePanel 中，当更新面板返回时，该按钮将重新启用。

于 2012-07-11T15:56:26.027 回答
0

禁用按钮不会导致回发。因此，如果您只禁用 OnClientClick 中的按钮，则不会发生 PostBack。

Try UseSubmitBehavior="false"，它的意思是“无论如何都会导致回发”。

<asp:Button runat="server" ID="BtnSubmit" 
OnClientClick="this.disabled = true; this.value = 'Submitting...';" 
UseSubmitBehavior="false" 
OnClick="BtnSubmit_Click" 
Text="Submit Me!" />

参考这个博客，它对你有用。 http://encosia.com/disable-a-button-control-during-postback/

于 2012-12-19T02:33:05.690 回答