在行数据绑定事件上找不到隐藏的输入控件

Question

这是我的aspx文件内容。

<asp:UpdatePanel ID="UpdatePanel1" runat="server" OnUnload="UpdatePanel_Unload">
<ContentTemplate>
<table>
<tr>
<td>
<input id="hdnAID" type="hidden" runat="server" />
<asp:GridView ID="GridView1" runat="server" OnRowCancelingEdit="GridView1_RowCancelingEdit"
OnRowEditing="GridView1_RowEditing" OnRowUpdating="GridView1_RowUpdating" OnRowDataBound="GridView1_RowDataBound" OnDataBound="GridView1_DataBound"
DataKeyNames="GeneralSettingID" EnableViewState="true">
<Columns>
<asp:TemplateField>
<ItemTemplate>
<GridEditPopupMenu:GridEditPopupMenu ID="GridEditPopupMenu1" runat="server" currenttemplate="ItemTemplate" ShowDeleteLink="0" />
</ItemTemplate>
<EditItemTemplate>
<GridEditPopupMenu:GridEditPopupMenu ID="GridEditPopupMenu1" runat="server" currenttemplate="EditItemTemplate" />
</EditItemTemplate>
</asp:TemplateField>
<asp:BoundField DataField="GeneralSettingID" HeaderText="SettingNo" ReadOnly="true" />
<asp:TemplateField HeaderText="SettingName">
<ItemTemplate>
<asp:Label ID="Label25" runat="server" Text='<%# Eval("GeneralSettingName") %>' />
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="txtUpdateGeneralSettingName" onfocus="this.blur();" runat="server" Text='<%# Bind("GeneralSettingName") %>'
Width="350px" />
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Values">
<ItemTemplate>
<asp:Label ID="Label23" runat="server" Text='<%# Eval("GeneralSettingValue") %>' />
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="txtUpdateGeneralSettingValue" runat="server" Text='<%# Bind("GeneralSettingValue") %>'
Width="600px" TextMode="MultiLine" Rows="6" />
</EditItemTemplate>
</asp:TemplateField>    
<asp:TemplateField HeaderText="Company1">
<ItemTemplate>
<asp:Label ID="Label28" runat="server" Text='<%# Eval("GeneralSettingCompany") %>' />
</ItemTemplate>
<ItemTemplate>
<asp:TextBox ID="txtUpdateGeneralSettingCompany" runat="server" Text='<%# Bind("GeneralSettingCompany") %>'
Width="100px" TextMode="MultiLine" Rows="1" Enabled="false" />
</ItemTemplate>
</asp:TemplateField> 
<asp:TemplateField HeaderText="Company2">                                     
<ItemTemplate>                                         
<asp:DropDownList  ID="drpCompanyList" runat="server" AutoPostBack="true" OnSelectedIndexChanged="drpCompanyList_SelectedIndexChanged" DataTextField="CompanyName" DataValueField="CompanyID"></asp:DropDownList>
<input id="hdnCompanyId" type="hidden" value='<%# Eval("GeneralSettingCompany") %>' runat="server" />
</ItemTemplate>                                                                                                                  
</asp:TemplateField>                                
</Columns>
</asp:GridView>
</td>
</tr>
</table>
</ContentTemplate>
</asp:UpdatePanel>

这是.cs方面.

private LMSDataAccess.LookupsDataContext LkpDC = new LMSDataAccess.LookupsDataContext(ConfigFile.DBConnStr);
private System.Collections.Generic.List<LMSDataAccess.GeneralSetting> GeneralSettingList = null;

protected void Page_Load(object sender, EventArgs e)
{
base.ModuleID = 27;
if (!IsPostBack)
{
if (Request["AID"] != null)
hdnAID.Value = Request["AID"];
BindData();
}
}
private void BindData()
{
GeneralSettingList = LkpDC.GeneralSettingsGetAll(Common.NVLInt(hdnAID.Value),null).ToList();
GridView1.DataSource = GeneralSettingList;
GridView1.DataBind();
}
protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
{
GridView1.EditIndex = -1;
BindData();
}
protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
{
GridView1.EditIndex = e.NewEditIndex;
BindData();
}
protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
TextBox txtUpdateGeneralSettingName = (TextBox)GridView1.Rows[e.RowIndex].FindControl("txtUpdateGeneralSettingName");
TextBox txtUpdateGeneralSettingValue = (TextBox)GridView1.Rows[e.RowIndex].FindControl("txtUpdateGeneralSettingValue");
var hdnCompany = (HiddenField)GridView1.Rows[e.RowIndex].FindControl("hdnCompanyId") as HiddenField;
string KeyValue = GridView1.DataKeys[e.RowIndex].Value.ToString();
LkpDC.GeneralSettingsUpdate(Convert.ToInt32(KeyValue),
txtUpdateGeneralSettingName.Text,
txtUpdateGeneralSettingValue.Text, 
Convert.ToInt32(hdnCompany.Value));
GridView1.EditIndex = -1;
BindData();
ResultCode = 0;
}
protected List<LMSDataAccess.Company> GetAllCompanies()
{
System.Collections.Generic.List<LMSDataAccess.Company> CompanyList = null;
LMSDataAccess.OrganizationDataContext OrgDC = new LMSDataAccess.OrganizationDataContext(ConfigFile.DBConnStr);
CompanyList = OrgDC.CompaniesGetAll(null).ToList();
return CompanyList;
}
protected void drpCompanyList_SelectedIndexChanged(object sender, EventArgs e)
{
DropDownList ddl = (DropDownList)sender;        
GridViewRow row = (GridViewRow)ddl.Parent.Parent;
var hdnCompany = row.FindControl("hdnCompanyId") as HiddenField;
hdnCompany.Value = ddl.SelectedValue;        
}
protected void GridView1_RowDataBound(object sender,GridViewRowEventArgs e) 
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
var ddl = e.Row.FindControl("drpCompanyList") as DropDownList;
//here is the problem.
var hdn = e.Row.FindControl("hdnCompanyId") as HiddenField;
if (ddl != null)
{
ddl.DataSource = GetAllCompanies();
ddl.DataValueField = "CompanyID";
ddl.DataTextField = "CompanyName";
ddl.DataBind();
}
}
}

我心爱的问题是在GridView1_RowDataBound和drpCompanyList_SelectedIndexChangedfired时无法获得hdnCompanyId元素。(如注释行所示(

我已经尝试过GridView1_RowDataBound事件方法，例如e.Row.FindControl("hdnCompanyId")但它没有用。 我的最终目标是设置并获取此元素来控制下拉列表中的选定项。

我认为代码写得很好，但我想我缺少一些关于用户控件元素层次结构的内容。 你能帮我解决我错过了什么吗？

Answer 1

我发现问题是选择了错误的输入转换类型。它必须是HtmlInputHidden而不是HiddenField.我希望有人能从这个问题中获得有用的信息。