DropDownList，获取 C# 中返回的 DataValueField
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DropDownList, getting DataValueField returned in C#
提问by David Tunnell
I have a drop down list that pulls data from a database to show some of its options:
我有一个下拉列表，可以从数据库中提取数据以显示其中的一些选项：
<asp:DropDownList ID="DropDownList3" runat="server" DataSourceID="SqlDataSource1"
DataTextField="Name" DataValueField="PK_Task" AppendDataBoundItems="true" CssClass="dropDownList">
<asp:ListItem Selected="True">General Support</asp:ListItem>
<asp:ListItem>Vacation</asp:ListItem>
<asp:ListItem>Sick Leave</asp:ListItem>
<asp:ListItem>Something Else</asp:ListItem>
</asp:DropDownList>
<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:ApplicationServices %>"
SelectCommand="SELECT [PK_Task], [Name] FROM [Task] WHERE ([PointPerson] LIKE '%' + @PointPerson + '%') AND [Status] NOT LIKE 'Done'">
<SelectParameters>
<asp:QueryStringParameter Name="PointPerson" Type="String" />
</SelectParameters>
</asp:SqlDataSource>
As you can see, I only display the [Name] column:
如您所见，我只显示 [Name] 列：
DataTextField="Name"
But I am also getting the primary key SELECT [PK_Task], [Name] FROM:
但我也得到了主键 SELECT [PK_Task], [Name] FROM：
DataValueField="PK_Task"
How do I get access to this primary key based on user selection. If a user selects a specific 'name' from the drop down menu, what C# can I use to get the corresponding primary key returned to me so I can save it in a variable?
如何根据用户选择访问此主键。如果用户从下拉菜单中选择特定的“名称”，我可以使用什么 C# 来获取返回给我的相应主键，以便将其保存在变量中？
The closest I have gotten is this, but all it does is return the string "PK_Task":
我得到的最接近的是这个，但它所做的只是返回字符串“PK_Task”：
String taskID = DropDownList3.DataValueField;
采纳答案by Felipe Oriani
You can use the SelectedValueproperty:
您可以使用该SelectedValue属性：
// to set
DropDownList3.SelectedValue = "1";
// to read
string value = DropDownList3.SelectedValue;
回答by COLD TOLD
try this
尝试这个
String taskID = DropDownList3.SelectedItem.Value;
回答by Md. Parvez Alam
any way you can use either
任何你可以使用的方式
dropdown3.selectedvalue
or
或者
dropdown3.selecteditem.value
