如何实现下拉菜单和为GridView选择特定id的按钮

Question

我有一个GridView，它当前显示所有记录（Event表中的所有事件）。现在我想添加一个显示每个事件的下拉框，然后添加一个按钮。单击按钮后，GridView将需要更新该事件id的数据。

我曾经尝试过，但遇到了问题。下面是我的代码，在问题出现之前。我将如何实现下拉菜单？

当前ASP.NET代码

<%@ Page Title="" Language="C#" MasterPageFile="~/admin/admin.master" AutoEventWireup="true" CodeFile="viewregistrant.aspx.cs" Inherits="admin_Default5" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="RegistrantId"
OnRowEditing="OnRowEditing" OnRowCancelingEdit="OnRowCancelingEdit"
OnRowUpdating="OnRowUpdating" OnRowDeleting="OnRowDeleting" 
        EmptyDataText="No records has been added." CellPadding="4" ForeColor="#333333" 
        GridLines="None" AllowPaging="True" OnPageIndexChanging="PagingRegistrant_PageIndexChanging" AllowSorting="True">
    <AlternatingRowStyle BackColor="White" />
<Columns>
    <asp:TemplateField HeaderText="First Name" ItemStyle-Width="80">
        <ItemTemplate>
            <asp:Label ID="lblFirstName" runat="server" Text='<%# Eval("FirstName") %>'></asp:Label>
        </ItemTemplate>
        <EditItemTemplate>
            <asp:TextBox ID="txtFirstName" runat="server" Text='<%# Eval("FirstName") %>'></asp:TextBox>
        </EditItemTemplate>
<ItemStyle Width="150px"></ItemStyle>
    </asp:TemplateField>
    <asp:TemplateField HeaderText="Last Name" ItemStyle-Width="80">
        <ItemTemplate>
            <asp:Label ID="lblLastName" runat="server" Text='<%# Eval("LastName") %>'></asp:Label>
        </ItemTemplate>
        <EditItemTemplate>
            <asp:TextBox ID="txtLastName" runat="server" Text='<%# Eval("LastName") %>'></asp:TextBox>
        </EditItemTemplate>
        <ItemStyle Width="150px"></ItemStyle>
    </asp:TemplateField>
    <asp:TemplateField HeaderText="Address Line 1" ItemStyle-Width="80">
        <ItemTemplate>
            <asp:Label ID="lblAddressLine1" runat="server" Text='<%# Eval("AddressLine1") %>'></asp:Label>
        </ItemTemplate>
        <EditItemTemplate>
            <asp:TextBox ID="txtAddressLine1" runat="server" Text='<%# Eval("AddressLine1") %>'></asp:TextBox>
        </EditItemTemplate>
<ItemStyle Width="150px"></ItemStyle>
    </asp:TemplateField>
    <asp:CommandField ButtonType="Link" ShowEditButton="true" 
        ShowDeleteButton="true" ItemStyle-Width="150">
<ItemStyle Width="150px"></ItemStyle>
    </asp:CommandField>
</Columns>
    <EditRowStyle BackColor="#2461BF" />
    <FooterStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
    <HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
    <PagerStyle BackColor="#2461BF" ForeColor="White" HorizontalAlign="Center" />
    <RowStyle BackColor="#EFF3FB" />
    <SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True" ForeColor="#333333" />
    <SortedAscendingCellStyle BackColor="#F5F7FB" />
    <SortedAscendingHeaderStyle BackColor="#6D95E1" />
    <SortedDescendingCellStyle BackColor="#E9EBEF" />
    <SortedDescendingHeaderStyle BackColor="#4870BE" />
</asp:GridView>
</asp:Content>

当前C#代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Configuration;
using System.Data.SqlClient;

public partial class admin_Default5 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!this.IsPostBack)
        {
            this.BindGrid();
        }
    }
    private void BindGrid()
    {
        string constr = ConfigurationManager.ConnectionStrings["Events2"].ConnectionString;
        using (SqlConnection con = new SqlConnection(constr))
        {
            using (SqlCommand cmd = new SqlCommand("spRegistrantsGridViewOld"))
            {
                cmd.CommandType = CommandType.StoredProcedure;  
                cmd.Parameters.AddWithValue("@Action", "SELECT");
                using (SqlDataAdapter sda = new SqlDataAdapter())
                {
                    cmd.Connection = con;
                    sda.SelectCommand = cmd;
                    using (DataTable dt = new DataTable())
                    {
                        sda.Fill(dt);
                        GridView1.DataSource = dt;
                        GridView1.DataBind();
                    }
                }
            }
        }
    }
    //Edit Button
    protected void OnRowEditing(object sender, GridViewEditEventArgs e)
    {
        GridView1.EditIndex = e.NewEditIndex;
        this.BindGrid();
    }
    //Update Button
    protected void OnRowUpdating(object sender, GridViewUpdateEventArgs e)
    {
        GridViewRow row = GridView1.Rows[e.RowIndex];
        int registrantId = Convert.ToInt32(GridView1.DataKeys[e.RowIndex].Values[0]);
        string firstName = (row.FindControl("txtFirstName") as TextBox).Text;
        string lastName = (row.FindControl("txtLastName") as TextBox).Text;
        string constr = ConfigurationManager.ConnectionStrings["Events2"].ConnectionString;
        using (SqlConnection con = new SqlConnection(constr))
        {
            using (SqlCommand cmd = new SqlCommand("spRegistrantsGridViewOld"))
            {
                cmd.CommandType = CommandType.StoredProcedure;
                cmd.Parameters.AddWithValue("@Action", "UPDATE");
                cmd.Parameters.AddWithValue("@RegistrantId", registrantId);
                cmd.Parameters.AddWithValue("@FirstName", firstName);
                cmd.Parameters.AddWithValue("@LastName", lastName);
                //cmd.Parameters.AddWithValue("@AddressLine1", addressLine1);
                //cmd.Parameters.AddWithValue("@AddressLine2", addressLine2);
                //cmd.Parameters.AddWithValue("@City", city);
                //cmd.Parameters.AddWithValue("@State", state);
                //cmd.Parameters.AddWithValue("@Zip", zip);
                //cmd.Parameters.AddWithValue("@Country", country);

                cmd.Connection = con;
                con.Open();
                cmd.ExecuteNonQuery();
                con.Close();
            }
        }
        GridView1.EditIndex = -1;
        this.BindGrid();
    }
    //Cancel Edit Button
    protected void OnRowCancelingEdit(object sender, EventArgs e)
    {
        GridView1.EditIndex = -1;
        this.BindGrid();
    }
    //Delete Button
    protected void OnRowDeleting(object sender, GridViewDeleteEventArgs e)
    {
        int registrantId = Convert.ToInt32(GridView1.DataKeys[e.RowIndex].Values[0]);
        string constr = ConfigurationManager.ConnectionStrings["Events2"].ConnectionString;
        using (SqlConnection con = new SqlConnection(constr))
        {
            using (SqlCommand cmd = new SqlCommand("spRegistrantsGridViewOld"))
            {
                cmd.CommandType = CommandType.StoredProcedure;
                cmd.Parameters.AddWithValue("@Action", "DELETE");
                cmd.Parameters.AddWithValue("@RegistrantId", registrantId);
                cmd.Connection = con;
                con.Open();
                cmd.ExecuteNonQuery();
                con.Close();
            }
        }
        this.BindGrid();
    }
    //JavaScript confirm delete
    //protected void OnRowDataBound(object sender, GridViewRowEventArgs e)
    //{
    //    if (e.Row.RowType == DataControlRowType.DataRow && e.Row.RowIndex != GridView1.EditIndex)
    //    {
    //        (e.Row.Cells[2].Controls[2] as LinkButton).Attributes["onclick"] = "return confirm('Do you want to delete this row?');";
    //    }
    //}
    protected void PagingRegistrant_PageIndexChanging(object sender, GridViewPageEventArgs e)
    {
       GridView1.PageIndex = e.NewPageIndex; 
        DataBind();
    }
    protected void DropDownListEvent_SelectedIndexChanged(object sender, EventArgs e)
    {
        GridView1.DataBind();
    }
}

我尝试的代码在下面不起作用。。。此处需要一些指针

我知道我需要以某种方式添加这个来填充下拉列表。。。

 if (!this.IsPostBack)
        {
            string events = DropDownListEvent.SelectedValue;
            using (SqlConnection sqlConn2 = new SqlConnection(ConfigurationManager.ConnectionStrings["Events2"].ConnectionString))
            {
                sqlConn2.Open();
                using (SqlCommand sqlCmd2 = new SqlCommand())
                {
                    sqlCmd2.Connection = sqlConn2;
                    sqlCmd2.CommandType = System.Data.CommandType.Text;
                    sqlCmd2.CommandType = System.Data.CommandType.StoredProcedure;
                    sqlCmd2.CommandText = "spGetAllEvents";
                    sqlCmd2.ExecuteNonQuery();
                    SqlDataReader sqlReader = sqlCmd2.ExecuteReader();
                    if (sqlReader.HasRows)
                    {
                        DropDownListEvent.DataSource = sqlReader;
                        DropDownListEvent.DataTextField = "EventName";
                        DropDownListEvent.DataValueField = "EventId";
                        DropDownListEvent.DataBind();
                    }
                    sqlConn2.Close();
                }
            }

这是为了让它在点击按钮后工作。。。

protected void ButtonChangeEvent_Click(object sender, EventArgs e)
    {
        string constr = ConfigurationManager.ConnectionStrings["Events2"].ConnectionString;
        using (SqlConnection con = new SqlConnection(constr))
        {
            using (SqlCommand cmd = new SqlCommand("spRegistrantsGridView"))
            {
                cmd.CommandType = CommandType.StoredProcedure;
                cmd.Parameters.AddWithValue("@Action", "SELECT");
                cmd.Parameters.Add("@EventId", SqlDbType.Int).Value = DropDownListEvent.SelectedValue;
                using (SqlDataAdapter sda = new SqlDataAdapter())
                {
                    cmd.Connection = con;
                    sda.SelectCommand = cmd;
                    using (DataTable dt = new DataTable())
                    {
                        sda.Fill(dt);
                        GridView1.DataSource = dt;
                        GridView1.DataBind();
                    }
                }
            }
        }

用ASP的下拉列表和按钮。。。

Choose event:
    <asp:DropDownList ID="DropDownListEvent" runat="server">
    </asp:DropDownList>
    <asp:Button ID="ButtonChangeEvent" runat="server" 
        onclick="ButtonChangeEvent_Click" Text="Button" />

这次尝试没有成功（和其他尝试一样）。。。我真的很想得到一些指导来让这件事发挥作用。非常感谢。

Answer 1

如注释中所述，在EditItemTemplate标记中添加一个下拉列表控件，如下所示：-

 <asp:TemplateField HeaderText="Events" ItemStyle-Width="80">
      <ItemTemplate>
         <asp:Label ID="lblEvent" runat="server" Text='<%# Eval("EventName") %>'>
         </asp:Label>
      </ItemTemplate>
      <EditItemTemplate>
          <asp:DropDownList ID="ddlEvents" runat="server" 
                            SelectedValue='<%# Eval("EventName") %>'></asp:DropDownList>
      </EditItemTemplate>
</asp:TemplateField>

然后，在网格视图中添加RowDataBoundEvent：-

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" 
              OnRowDataBound="GridView1_RowDataBound"

在代码隐藏文件中，添加rowDataBound事件处理程序方法，找到我们添加并绑定的下拉列表：-

protected void grdEmployees_RowDataBound(object sender, GridViewRowEventArgs e)
{
   if (e.Row.RowType == DataControlRowType.DataRow)
   {
       if (e.Row.RowState && DataControlRowState.Edit > 0)
       {
           DropDownList ddList= (DropDownList)e.Row.FindControl("ddlEvents");
           //Now call your ADO.NET code and bind the dropdownlist.
       }
}