获取转发器控件中的选定下拉列表值
本文关键字:下拉列表 转发器 控件 获取 | 更新日期: 2023-09-27 17:57:10
我在中继器控件中有一个下拉列表,我正在尝试获取其值,并且得到"对象引用未设置为对象的实例"。我不确定还能尝试什么。 谢谢
ASPX 代码:
<asp:Repeater ID="GeneralRepeater" runat="server"
OnItemDataBound="GeneralRepeater_OnItemDataBound"
onitemcommand="GeneralRepeater_ItemCommand">
<HeaderTemplate></HeaderTemplate>
<ItemTemplate>
<tr>
<td class="style2">
</td>
<td class="style2">
<asp:DropDownList ID="GeneralDDL" AppendDataBoundItems="true" DataTextField="DiagnosisCode"
DataValueField="DiagnosisCode" runat="server" AutoPostBack="True" />
</td>
</tr>
</ItemTemplate>
<FooterTemplate></FooterTemplate>
</asp:Repeater>
</asp:Panel>
代码隐藏:
protected void GeneralRepeater_OnItemDataBound(object sender,
RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item ||
e.Item.ItemType == ListItemType.AlternatingItem)
{
DropDownList myDDL = (DropDownList)e.Item.FindControl("GeneralDDL");
Diagnosis oDiagnosis = new Diagnosis();
DataView dv = new DataView(oDiagnosis.GetDiagnosis());
myDDL.DataSource = dv;
myDDL.DataTextField = "DiagnosisCode";
myDDL.DataValueField = "DiagnosisCode";
myDDL.DataBind();
}
}
protected void cmdSave_Click(object sender, EventArgs e)
{
string ProductSelected;
string FeatureSelected;
string SectionSelected;
foreach(RepeaterItem dataItem in GeneralRepeater.Items)
{
ProductSelected = ((DropDownList)GeneralRepeater.FindControl("GeneralDDL")).SelectedItem.Text; //error Object reference not set to an instance of an object.
}
}
我在保存所选值时遇到问题。
我在代码中发现的是你正在循环访问通用中继器项目。您正在以数据项的形式访问转发器项。 我在这里尝试了这段代码,理想情况下您的代码应该说
foreach(RepeaterItem dataItem in GeneralRepeater.Items)
{
ProductSelected = ((DropDownList)dataItem.FindControl("GeneralDDL")).SelectedItem.Text; //No error
}
而不是
foreach(RepeaterItem dataItem in GeneralRepeater.Items)
{
ProductSelected = ((DropDownList)GeneralRepeater.FindControl("GeneralDDL")).SelectedItem.Text; //error Object reference not set to an instance of an object.
}