【发布时间】：2022-01-14 17:19:25
【问题描述】：
我在 DetailsView 中有两个下拉列表，第一个下拉列表 DepartmentDropDown 使用以下数据源从后面的代码中成功加载数据
<asp:ObjectDataSource ID="dsDepartments" runat="server" SelectMethod="GetDepartments"
TypeName="MyCode.DepartmentEmployeeAssociations">
</asp:ObjectDataSource>
第二个下拉列表EmployeeDropDown 使用基于第一个下拉列表中的部门选择的另一个数据源（注释代码有效并加载详细信息视图，但不加载控制参数代码）：
<asp:ObjectDataSource ID="dsEmployees" runat="server" SelectMethod="GetAllEmployees"
TypeName="MyCode.DepartmentEmployeeAssociations" DataObjectTypeName="Employee">
<SelectParameters>
<%--<asp:Parameter Name="deptId" Type="Int32" DefaultValue="7" />--%>
<asp:ControlParameter ControlID="DepartmentDropDown" Name="deptId" PropertyName="SelectedValue" Type="Int32" />
</SelectParameters>
</asp:ObjectDataSource>
这是我的 GridView 和 DetailsView 中的代码
<asp:Panel ID="AssociationView" runat="server" Visible="false">
<asp:GridView ID="gvAssociations" runat="server" AutoGenerateColumns="False" CssClass="GridViewStyle"
EmptyDataText="No rules defined" Width="100%" AllowPaging="True" GridLines="None"
DataKeyNames="Id" EnableModelValidation="True" DataSourceID="dsAssociations"
OnSelectedIndexChanged="gvAssociations_SelectedIndexChanged">
<Columns>
<asp:CommandField ShowSelectButton="true" SelectText="View" ItemStyle-Width="50px">
<ItemStyle Width="50px"></ItemStyle>
</asp:CommandField>
<asp:BoundField DataField="Id" HeaderText="Id" SortExpression="Id" Visible="False" />
<asp:BoundField DataField="Value1" HeaderText="Employee" SortExpression="Value1" Visible="false" />
<asp:BoundField DataField="Value1Description" HeaderText="Employee" NullDisplayText="*" />
<asp:BoundField DataField="Value2" HeaderText="Department" SortExpression="Value2" Visible="false" />
<asp:BoundField DataField="Value2Description" HeaderText="Department" NullDisplayText="*" />
<asp:CommandField ShowDeleteButton="True" />
</Columns>
</asp:GridView>
<div class="DetailsContainer">
<asp:DetailsView ID="dvAssociations" runat="server" Height="50px" GridLines="None"
CellPadding="5" AutoGenerateRows="False" DataKeyNames="sId" EnableModelValidation="True"
OnItemCreated="dvAssociations_ItemCreated" OnItemUpdating="dvAssociations_ItemUpdating"
OnItemInserting="dvAssociations_ItemInserting">
<Fields>
<asp:BoundField DataField="Id" HeaderText="ID" ReadOnly="True" InsertVisible="False" Visible="false" />
<asp:TemplateField HeaderText="Department">
<ItemTemplate>
<asp:DropDownList ID="DepartmentDropDown" runat="server" SelectedValue='<%# Bind("Value2") %>'
DataSourceID="dsDepartments" DataValueField="DepartmentId" DataTextField="Name"
Enabled="false" AutoPostBack="true">
</asp:DropDownList>
</ItemTemplate>
<EditItemTemplate>
<asp:DropDownList ID="DepartmentDropDown" runat="server" SelectedValue='<%# Bind("Value2") %>'
DataSourceID="dsDepartments" DataValueField="DepartmentId" DataTextField="Name"
Enabled="true" AutoPostBack="true">
</asp:DropDownList>
</EditItemTemplate>
<InsertItemTemplate>
<asp:DropDownList ID="DepartmentDropDown" runat="server" SelectedValue='<%# Bind("Value2") %>'
DataSourceID="dsDepartments" DataValueField="DepartmentId" DataTextField="Name"
Enabled="true" AutoPostBack="true">
</asp:DropDownList>
</InsertItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Employee">
<ItemTemplate>
<asp:DropDownList ID="EmployeeDropDown" runat="server"
DataSourceID="dsEmployees" DataValueField="EmployeeId" DataTextField="FullName"
Enabled="false">
</asp:DropDownList>
</ItemTemplate>
<EditItemTemplate>
<asp:DropDownList ID="EmployeeDropDown" runat="server"
DataSourceID="dsEmployees" DataValueField="EmployeeId" DataTextField="FullName"
Enabled="true">
</asp:DropDownList>
</EditItemTemplate>
<InsertItemTemplate>
<asp:DropDownList ID="EmployeeDropDown" runat="server"
DataSourceID="dsEmployees" DataValueField="EmployeeId" DataTextField="FullName"
Enabled="true">
</asp:DropDownList>
</InsertItemTemplate>
</asp:TemplateField>
<asp:CommandField ShowEditButton="True" ShowInsertButton="True" ShowDeleteButton="True" />
</Fields>
</asp:DetailsView>
</div>
</asp:Panel>
以及背后的代码：
protected void gvAssociations_SelectedIndexChanged(object sender, EventArgs e)
{
dvAssociations.PageIndex = gvAssociations.SelectedRow.DataItemIndex;
}
protected void dvAssociations_ItemCreated(object sender, EventArgs e)
{
if (dvAssociations.DataItem == null)
return;
// Some checks
}
protected void dvAssociations_ItemUpdating(object sender, DetailsViewUpdateEventArgs e)
{
//some code
}
protected void dvAssociations_ItemInserting(object sender, DetailsViewUpdateEventArgs e)
{
e.NewValues["Value1"] = ((DropDownList)((DetailsView)sender).FindControl("EmployeeDropDown")).SelectedValue;
}
public List<Department> GetDepartments()
{
// code to return List<Department> departments
// other code
return departments;
}
public List<Employee> GetAllEmployees(int deptId)
{
// code to return List<Employee> employees
// other code
return employees;
}
我尝试了其他 SO 文章中给出的各种建议，但仍然无法完成这项工作。当我添加了控制参数时，我的页面不加载，但如果我将其更改为普通参数，它就可以工作。
<asp:ControlParameter ControlID="DepartmentDropDown" Name="deptId" PropertyName="SelectedValue" Type="Int32" />
我不确定它不喜欢什么，它似乎没有绑定详细信息视图中的数据。我按照其他帖子中的建议将AutoPostBack 添加到true 到第一个下拉列表中，并从第二个下拉列表中删除了SelectedValue='<%# Bind("Value1") %>'，但似乎没有任何效果。
任何帮助将不胜感激。
【问题讨论】：
标签： asp.net detailsview cascadingdropdown