C# 在网格视图中获取下拉菜单的选定索引和行

我有一个gridview，其中如果满足某些条件，单元格将填充一个下拉列表：

protected void viewThemeTypeAssociationsGridView_OnRowDataBound(Object sender, GridViewRowEventArgs e)
{
    if (e.Row.Cells[1].Text == " ")
    {
        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            e.Row.Cells[1].Text = "Not Assigned";
            DropDownList chooseThemeTypeDropDown = (DropDownList)e.Row.FindControl("chooseThemeTypeDropDown");
            chooseThemeTypeDropDown.Visible = true;
        }
    }
}

这是一张照片：

这是下拉列表的多个副本，在某些行中可见。如何访问已更改下拉列表的选定索引及其所在的行

我在想这样的事情，但不起作用：

protected void chooseThemeTypeDropDown_OnSelectedIndexChanged(object sender, EventArgs e)
{
    DropDownList chooseThemeTypeDropDown = (DropDownList)e.Row.FindControl("chooseThemeTypeDropDown");
}

编辑：如果有帮助，这里是gridview：

                        <asp:GridView ID="viewThemeTypeAssociationsGridView" runat="server" AutoGenerateColumns="False"
                            BackColor="#DEBA84" BorderColor="#DEBA84" BorderStyle="None" BorderWidth="1px"
                            CellPadding="3" CellSpacing="2" DataSourceID="SqlDataSource6" OnRowDataBound="viewThemeTypeAssociationsGridView_OnRowDataBound">
                            <Columns>
                                <asp:BoundField DataField="Name" HeaderText="Name" SortExpression="Name" />
                                <asp:BoundField DataField="Type" HeaderText="Type" SortExpression="Type" />
                                <asp:TemplateField HeaderText="Choose Theme Type">
                                    <ItemTemplate>
                                        <asp:DropDownList ID="chooseThemeTypeDropDown" runat="server" DataTextField="Type" DataValueField="PK_ThemeType" AutoPostBack="true" DataSourceID="SqlDataSource9" CssClass="dropDownList" OnDataBound="chooseThemeTypeDropDown_OnDataBound" Visible="false" OnSelectedIndexChanged="viewProductAssociationsDropDown_OnSelectedIndexChanged">
                                        </asp:DropDownList>
                                        <asp:SqlDataSource ID="SqlDataSource9" runat="server" ConnectionString="<%$ ConnectionStrings:ApplicationServices %>"
                                            SelectCommand="SELECT [Type], [PK_ThemeType] FROM [ThemeType] WHERE [Deleted] = 0 ORDER BY [Type] ASC">
                                        </asp:SqlDataSource>
                                    </ItemTemplate>
                                </asp:TemplateField>
                            </Columns>
                            <FooterStyle BackColor="#F7DFB5" ForeColor="#8C4510" />
                            <HeaderStyle BackColor="#A55129" Font-Bold="True" ForeColor="White" />
                            <PagerStyle ForeColor="#8C4510" HorizontalAlign="Center" />
                            <RowStyle BackColor="#FFF7E7" ForeColor="#8C4510" />
                            <SelectedRowStyle BackColor="#738A9C" Font-Bold="True" ForeColor="White" />
                            <SortedAscendingCellStyle BackColor="#FFF1D4" />
                            <SortedAscendingHeaderStyle BackColor="#B95C30" />
                            <SortedDescendingCellStyle BackColor="#F1E5CE" />
                            <SortedDescendingHeaderStyle BackColor="#93451F" />
                        </asp:GridView>
                        <asp:SqlDataSource ID="SqlDataSource6" runat="server" ConnectionString="<%$ ConnectionStrings:ApplicationServices %>"
                            SelectCommand="SELECT [Theme].[Name], [ThemeType].[Type] FROM [Theme] LEFT OUTER JOIN [ThemeType] ON [Theme].[ThemeTypeId] = [ThemeType].[PK_ThemeType] JOIN [ProductTheme] ON [ProductTheme].[ThemeId]=[Theme].[PK_Theme] WHERE ProductTheme.ProductID LIKE @productParam AND ProductTheme.ThemeId = Theme.PK_Theme AND COALESCE([THEME].[THEMETYPEID], 'null') LIKE @assignedParam GROUP BY [Theme].[Name], [ThemeType].[Type] ORDER BY CASE WHEN [ThemeType].[Type] IS NULL THEN 0 ELSE 1 END, [Theme].[Name]">
                            <SelectParameters>
                                <asp:QueryStringParameter Name="productParam" Type="String" />
                                <asp:QueryStringParameter Name="assignedParam" Type="String" />
                            </SelectParameters>
                        </asp:SqlDataSource>

---

sender

将为您提供启动事件的控件，如下所示：

protected void chooseThemeTypeDropDown_OnSelectedIndexChanged(object sender, EventArgs e)
{
    DropDownList chooseThemeTypeDropDown = sender as DropDownList;

    // Check to make sure the drop down exists before we try to work with it
    if(chooseThemeTypeDropDown != null)
    {
        // Put logic here to work with drop down list
    }
}

---

您确实需要将if（e.Row.RowType==DataControlRowType.DataRow）移动到条件in

OnRowDataBound

的外部

现在，如果将

chooseThemeTypeDropDown.AutoPostBack

设置为true，并将其设置为处理

onselectedexchanged

事件，则可以通过将

对象发送器

转换为

DropDownList

来找到

chooseThemeTypeDropDown

的正确实例

要获取行索引，这更困难。最快但有点老套的方法是将行索引附加到GridView的

RowDataBound

事件上的每个

chooseThemeTypeDropDown

ID

---

choosetheMetypropdown.ID=选择SetHementPedPropDown.ID+e.Row.RowIndex
我已将自动回邮设置为true，并且OnSelectedIndex已更改。System.Diagnostics.Debug.WriteLine（选择Sethemetypedropdown.SelectedItem.Value.ToString（））；结果是没有输出，当我更改索引时，它会在回发时重新更改。我做错了什么？您是将发送方强制转换为DDL，还是仍然以问题代码中的错误方式进行转换？在该行上放置断点，并在运行时检查SelectedItem的值。我希望您仍然在这里回答问题。我正在使用chooseThemeTypeDropDown.ID=chooseThemeTypeDropDown.ID+e.Row.RowIndex；将行索引附加到ID，但在调用它时它不会显示：System.Diagnostics.Debug.WriteLine（chooseThemeTypeDropDown.ID.ToString（））；结果：chooseThemeTypeDropDown，没有附加值。嗯，我不确定这是否有效。这一点甚至更难理解，但是如果您今天需要让它工作，您可以使用
CssClass
来存储rowindex属性。这不是一个我会觉得舒服的投入生产，但它会工作。
protected void chooseThemeTypeDropDown_OnSelectedIndexChanged(object sender, EventArgs e)
{
    DropDownList chooseThemeTypeDropDown = sender as DropDownList;

    // Check to make sure the drop down exists before we try to work with it
    if(chooseThemeTypeDropDown != null)
    {
        // Put logic here to work with drop down list
    }
}