如何从更新面板中的动态控件获取值

本文介绍了如何从更新面板中的动态控件获取值的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 限时删除！！ 我已经在下面给出了添加动态控件的代码，如何从这里获取值 DropDownList ddlAgent = new DropDownList（）; ddlAgent.EnableViewState = false ; ddlAgent.CssClass = RegsSelect; ddlAgent.ID = ddlAgent; ddlAgent.ClientIDMode = ClientIDMode.Static; ddlAgent.Attributes.Add（ style， margin-left：-4px; height：40px; width：328px;）; upText.ContentTemplateContainer.Controls.Add（ddlAgent）; // 使用下拉列表绑定数据 CUser objUser = new CUser（）; ddlAgent.DataSource = objUser.GetUserByRoleId（ 4 ）; ddlAgent.DataValueField = Id; ddlAgent.DataTextField = FirstName; ddlAgent.DataBind（）; 现在获取控制权 DropDownList ddlAgent =（DropDownList）upText.ContentTemplateContainer.FindControl（ ddlAgent）; 给出空参考例外 它是从上一个下拉列表的选定索引创建的，它放在updatepanel中解决方案 始终在Page_Init事件中创建动态控件（阅读此内容 [ ^ ]和此 [ ^ ]获取详细信息）。 更改您的CS。试试这个： // 在此创建控件页面事件 受保护 void Page_Init（ object sender，EventArgs e） { DropDownList ddlAgent = new DropDownList（）; ddlAgent.EnableViewState = false ; ddlAgent.CssClass = RegsSelect; ddlAgent.ID = ddlAgent; ddlAgent.ClientIDMode = ClientIDMode.Static; ddlAgent.Attributes.Add（ style， margin-left：-4px; height：40px; width：328px;）; upText.ContentTemplateContainer.Controls.Add（ddlAgent）; } 现在，找到控件并将其绑定在您的函数或方法中。试试这个： DropDownList ddlAgent =（DropDownList）upText.ContentTemplateContainer.FindControl（ ddlAgent）; // 现在您将无法获得null referance异常 // 使用下拉列表绑定数据 CUser objUser = new CUser（）; ddlAgent.DataSource = objUser.GetUserByRoleId（ 4 ）; ddlAgent.DataValueField = Id; ddlAgent.DataTextField = FirstName; ddlAgent.DataBind（）; - Amit I have given code for adding dynamic Control below , how to get value from this DropDownList ddlAgent = new DropDownList(); ddlAgent.EnableViewState = false; ddlAgent.CssClass = "RegsSelect"; ddlAgent.ID = "ddlAgent"; ddlAgent.ClientIDMode = ClientIDMode.Static; ddlAgent.Attributes.Add("style", "margin-left:-4px;height:40px;width:328px;"); upText.ContentTemplateContainer.Controls.Add(ddlAgent); //Binding data with dropdownlist CUser objUser = new CUser(); ddlAgent.DataSource = objUser.GetUserByRoleId(4); ddlAgent.DataValueField = "Id"; ddlAgent.DataTextField = "FirstName"; ddlAgent.DataBind(); now to get control DropDownList ddlAgent=(DropDownList) upText.ContentTemplateContainer.FindControl("ddlAgent"); which gives Null Reference Exceptionit is created from selected index of previous dropdownlist and it is placed in updatepanel 解决方案 Always create your dynamic control in Page_Init event (Read this[^] and this[^] for a detailed information).Change your CS. Try this://Create the controls in this page eventprotected void Page_Init(object sender, EventArgs e){ DropDownList ddlAgent = new DropDownList(); ddlAgent.EnableViewState = false; ddlAgent.CssClass = "RegsSelect"; ddlAgent.ID = "ddlAgent"; ddlAgent.ClientIDMode = ClientIDMode.Static; ddlAgent.Attributes.Add("style", "margin-left:-4px;height:40px;width:328px;"); upText.ContentTemplateContainer.Controls.Add(ddlAgent);}Now, find the control and bind it in your function or method. Try this:DropDownList ddlAgent=(DropDownList) upText.ContentTemplateContainer.FindControl("ddlAgent"); //Now you won't get a null referance exception//Binding data with dropdownlistCUser objUser = new CUser();ddlAgent.DataSource = objUser.GetUserByRoleId(4);ddlAgent.DataValueField = "Id";ddlAgent.DataTextField = "FirstName";ddlAgent.DataBind();--Amit 这篇关于如何从更新面板中的动态控件获取值的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 1403页，肝出来的..