我的页面首先显示事件的下拉菜单。用户从此下拉菜单中选择一个事件，然后单击一个按钮。单击按钮后，GridView将填充相应的数据。一切正常。
然后，当用户查看此数据时，有两个可用的按钮：编辑和删除。单击编辑应该允许用户在那里编辑行。然后编辑按钮变为更新按钮，然后他们将单击以更新行。这是不起作用的区域。
现在，在用户点击编辑之前，一切都很好。当他们单击编辑时，程序会崩溃或清除GridView。我知道我的代码有问题...我认为它与BindGrid()有关（参见我的C＃）。任何人都可以帮我这个吗？
<%@ Page Title="" Language="C#" MasterPageFile="~/admin/admin.master" AutoEventWireup="true" CodeFile="copycopyviewregistrant.aspx.cs" Inherits="admin_Default5" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
Choose event:
<asp:DropDownList ID="DropDownListEvent" runat="server">
</asp:DropDownList>
<asp:Button ID="ButtonChangeEvent" runat="server"
onclick="ButtonChangeEvent_Click" Text="Button" />
<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>
C＃
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;
using System.IO;
public partial class admin_Default5 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
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();
}
}
}
}
private void BindGrid()
{
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");
using (SqlDataAdapter sda = new SqlDataAdapter())
{
cmd.Connection = con;
sda.SelectCommand = cmd;
using (DataTable dt = new DataTable())
{
sda.Fill(dt);
GridView1.DataSource = dt;
GridView1.DataBind();
this.BindGrid();
}
}
}
}
}
//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("spRegistrantsGridView"))
{
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("spRegistrantsGridView"))
{
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 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();
}
}
}
}
}
}