DropdownList SelectedIndexChanged事件未触发 [英] DropdownList SelectedIndexChanged event not firing

问题描述

我填充了子类别下拉列表下拉列表。

但是当我在类别下拉列表中更改类别时，其SelectedIndexChanged事件未触发。我的代码是： -



加价： -

 <   td  >  <   asp：DropDownList     ID   =  selectcategorydd    runat   =  server  
   
                                   class   =  styledselect_form_1    AutoPostBack   =  true  
   
                                     AppendDataBoundItems   =   True  
   
                                  < span class =code-attribute> onselectedindexchanged   =  selectcategorydd_SelectedIndexChanged >  <   / asp：DropDownList  >  
 <   / td  >  
 <   td  < span class =code-keyword>>  
 <   asp：RequiredFieldValidator     ID   =  rfvc    runat   =  server  
   
                              < span class =code-attribute>     Contro lToValidate   =  selectcategorydd      ForeColor   = 红色    ErrorMessage   = 选择类别 >  * <   / asp：RequiredFieldValidator  >  
 <   / td  >  
 <   / tr  >  
 < span class =code-keyword><   tr  >  
 <   th     valign   =   top   > 子类别：<   / th  >  
 <   td    < span class =code-attribute> style   =  width：30％ < span class =code-keyword>>  
 <   asp：DropDownList     ID   =  choicescategorydd    runat   =  server    AutoPostBack   =  true < span class =code-attribute>   AppendDataBoundItems   =  True  
   
                                   class   =  styledselect_form_1 >  <   / asp：DropDownList  >  

CodeBehind：

 protected void Fill_Category（）
 {
 DataTable categorytbl = d.fill_category（）; 
 selectcategorydd.DataSource = categorytbl; 
 selectcategorydd.DataTextField =CategoryName; 
 selectcategorydd.DataValueField =CategoryID; 
 selectcategorydd.DataBind（）; 
 
 selectcategorydd.Items.Insert（0， -  Select--）; 
} 
 
 
 
 protected void selectcategorydd_SelectedIndexChanged（object sender，EventArgs e）
 {
 int catid = int.Parse（selectcategorydd.SelectedValue ）; 
 
 DataTable t1 = d.cascadesubcat（catid）; 
 choosecategorydd.DataSource = t1; 
 chosencategorydd.DataTextField =SubCategoryName; 
 chosencategorydd.DataValueField =SubCategoryID; 
 choosecategorydd.DataBind（）; 
 choosecategorydd.Items.Insert（0， -  Select--）; 
} 
 

注意： - viewstate在页面指令中也是如此。

解决方案

< blockquote>删除choicescategorydd.DataValueField =SubCategoryID;这一行并尝试将DataValueField设为SubCategoryName。

I m populating subcategory dropdown fom category dropdown.
but when i change category in category dropdown its "SelectedIndexChanged"event is not firing.here is my code:-

Markup:-

<td><asp:DropDownList ID="selectcategorydd" runat="server"

                class="styledselect_form_1" AutoPostBack="true"

                 AppendDataBoundItems="True"

                onselectedindexchanged="selectcategorydd_SelectedIndexChanged"></asp:DropDownList>
        </td>
        <td>
            <asp:RequiredFieldValidator ID="rfvc" runat="server"

                ControlToValidate="selectcategorydd"  ForeColor="Red" ErrorMessage="Select category">*</asp:RequiredFieldValidator>
            </td>
        </tr>
        <tr>
        <th valign="top" > SubCategory:</th>
        <td style="width:30%">
            <asp:DropDownList ID="selectscategorydd" runat="server" AutoPostBack="true" AppendDataBoundItems="True"

                class="styledselect_form_1"></asp:DropDownList>

CodeBehind:

protected void Fill_Category()
       {
           DataTable categorytbl = d.fill_category();
           selectcategorydd.DataSource = categorytbl;
           selectcategorydd.DataTextField = "CategoryName";
           selectcategorydd.DataValueField = "CategoryID";
           selectcategorydd.DataBind();

           selectcategorydd.Items.Insert(0, "--Select--");
       }



       protected void selectcategorydd_SelectedIndexChanged(object sender, EventArgs e)
       {
           int catid = int.Parse(selectcategorydd.SelectedValue);

           DataTable t1 = d.cascadesubcat(catid);
           selectscategorydd.DataSource = t1;
           selectscategorydd.DataTextField = "SubCategoryName";
           selectscategorydd.DataValueField = "SubCategoryID";
           selectscategorydd.DataBind();
           selectscategorydd.Items.Insert(0, "--Select--");
       }

Note:- viewstate is also true in page directive.

解决方案

Remove selectscategorydd.DataValueField = "SubCategoryID"; this line and try or make DataValueField to SubCategoryName.

这篇关于DropdownList SelectedIndexChanged事件未触发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IT屋！