C# 我想在用户从回发页面的下拉列表中选择任何项目时立即调用函数。如何操作？ 地位 接受 拒绝 代码： 受保护的void Repeater1\u ItemDataBound（对象发送方，RepeaterItemEventArgs e） { //DropDownList DropDownList1=（DropDownList）发送方； //string SelectedValue=DropDownList1.SelectedValue； 如果（e.Item.ItemType==ListItemType.Item | | e.Item.ItemType==ListItemType.AlternatingItem） { DropDownList ddldrop=（DropDownList）e.Item.FindControl（“DropDownList1”）； int value=Convert.ToInt32（ddldrop.SelectedValue）； 主管sup=新主管（）； 如果（值==1）{ sup.Status=“接受”； sup.Save（）； } } }

更改：

<asp:Repeater ID="Repeater1" runat="server" OnItemDataBound="Repeater1_ItemDataBound">
                <ItemTemplate>
                    <tr>
                        <td><%#subtypes.FindByPk(Convert.ToInt32(Eval("SubitemID"))).title%></td>
                        <td><%#Eval("quantity")%></td>
                        <td><%#ThanaRecord.FindByPk(Convert.ToInt32(Eval("Thanaid"))).title%></td>
                        <td><%#Eval("created_at")%></td>
                        <td> <% if (Employee.GetCurrentEmployee().role == "Admin") { %>
                            <a href="AddDemand.aspx?type=update&id=<%#Eval("id")%>">EDIT</a>

                                <a href="AddDemand.aspx?type=delete&id=<%#Eval("id")%>">DELETE</a>
                            <% } %>
                        <%if (Employee.GetCurrentEmployee().role == "SuperVisor")
                           { %>
                          <asp:DropDownList ID="DropDownList1" runat="server" Width="120px"  AutoPostBack="false" CssClass="form-control">
                     <asp:ListItem Text="Status" Value="0">Status</asp:ListItem>
                              <asp:ListItem Text="Accept" Value="1">Accept</asp:ListItem>
                    <asp:ListItem Text="Reject" Value="2">Reject</asp:ListItem>

                </asp:DropDownList>

                            <%--<asp:textbox runat="server" id="textTest"></asp:textbox>--%>
                        </td>
                        <%} %>
                    </tr>
                </ItemTemplate>
            </asp:Repeater>
CODE:
 protected void Repeater1_ItemDataBound(object sender, RepeaterItemEventArgs e)
    {
        //DropDownList DropDownList1 = (DropDownList)sender;
        //string SelectedValue = DropDownList1.SelectedValue;
        if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
        {
            DropDownList ddldrop = (DropDownList)e.Item.FindControl("DropDownList1");
            int  value =Convert.ToInt32( ddldrop.SelectedValue);
            Supervisor sup = new Supervisor();
        if (value == 1) {
                sup.Status = "Accept";
                sup.Save();
            }
        }
    }

这会立即触发事件

注意： 此行为创建一个

POST

，它将触发

Page\u Load

，如果在触发下拉列表事件之前在中继器上调用

DataBind（）

，它将根本不会触发。确保

DataBind（）

由

保护！IsPostback

以避免抑制事件

例如：

// event handler - this event will fire for ALL drop downs in the repeater
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{

  // this will tell which drop down fired the event
  var dropdown = (DropDownList)sender;
  // this will tell you the repeater item containing the drop down
  var repeateritem = (RepeaterItem)dropdown.NamingContainer;
}

---

实现SelectedIndexChanged事件并将AutoPostBack设置为True。

首先，添加SelectedIndexChanged事件，并将dropdownlist控件上的AutoPostBack设置为True

然后在代码隐藏中添加以下代码，只需排除ScriptManager部分，并使用您的方法存储或显示您喜欢的任何位置

protected void Page_Load(object sender, EventArgs e)
{
    if(!IsPostback)
    {
        Repeater1.DataSource = SomeDataSource; // whatever
        Repeater1.DataBind();
    }
}

---

AutoPostBack

必须是

True

事件处理程序才能立即启动，但dropdownlist selected index事件不会在Repeater中找到dropdown但如何在dropdown selected index change事件中找到Repeater中的dropdown值？@Hishahid很高兴我付出了所有努力来帮助您，您标记了另一个答案，即使他们是一样的，我也是第一个。我感谢你们的帮助，但我更了解那个人的代码，它对我很有用。@Hishamshaid不担心。这毕竟是你的选择。有时候会令人沮丧。特别是当你像我一样脾气暴躁的时候：）

// event handler - this event will fire for ALL drop downs in the repeater
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{

  // this will tell which drop down fired the event
  var dropdown = (DropDownList)sender;
  // this will tell you the repeater item containing the drop down
  var repeateritem = (RepeaterItem)dropdown.NamingContainer;
}

protected void Page_Load(object sender, EventArgs e)
{
    if(!IsPostback)
    {
        Repeater1.DataSource = SomeDataSource; // whatever
        Repeater1.DataBind();
    }
}

protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
        DropDownList ddl = sender as DropDownList;
        RepeaterItem rptItems = ddl.NamingContainer as RepeaterItem;
        DropDownList ddlItems = rptItems.FindControl("DropDownList1") as DropDownList;
        ScriptManager.RegisterStartupScript(this.Page, typeof(Page), "showname", "javascript: alert('" + ddlItems.SelectedItem.ToString()   + "');", true);
}