我在试图找出这个问题时已经达到了一个静止点。所以我的Web应用程序有一个下拉列表，用于填充gridview。然后在gridview下面的标签中，它应该显示所选作者的数据库中的所有行（此Web应用程序将使用分页）。每当我选择其他作者时，我的标签会抛出一些疯狂的价值。我需要在代码中调整什么？
CSS代码：
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="Homemade01.WebForm1" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Welcome to our Master/Detail Filtering with a DropDownList example</title>
<style type="text/css">
.auto-style1 {
font-size: xx-large;
}
.auto-style2 {
color: #FF0000;
}
</style>
</head>
<body>
<form id="form1" runat="server">
<div>
<span class="auto-style1">Welcome to our Master/Detail Filtering with a DropDownList example:</span><br />
<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:ConnectionString %>" ProviderName="<%$ ConnectionStrings:ConnectionString.ProviderName %>" SelectCommand="SELECT firstName + ' ' + lastName AS FullName, lastName, authorID, firstName FROM Authors ORDER BY lastName, authorID"></asp:SqlDataSource>
<br />
Please select an author from the list:
<asp:DropDownList ID="DropDownList1" runat="server" DataSourceID="SqlDataSource1" Height="16px" Width="248px" AutoPostBack="True" DataTextField="FullName" DataValueField="authorID">
</asp:DropDownList>
<br />
<br />
<asp:SqlDataSource ID="SqlDataSource2" runat="server" ConnectionString="<%$ ConnectionStrings:ConnectionString %>" ProviderName="<%$ ConnectionStrings:ConnectionString.ProviderName %>" SelectCommand="SELECT Authors.firstName, Authors.lastName, AuthorISBN.ISBN, Titles.title, Publishers.publisherName, Titles.price, Titles.editionNumber FROM (((Authors INNER JOIN AuthorISBN ON Authors.authorID = AuthorISBN.authorID) INNER JOIN Titles ON AuthorISBN.ISBN = Titles.ISBN) INNER JOIN Publishers ON Titles.publisherID = Publishers.publisherID) WHERE (Authors.authorID = ?)">
<SelectParameters>
<asp:ControlParameter ControlID="DropDownList1" Name="?" PropertyName="SelectedValue" />
</SelectParameters>
</asp:SqlDataSource>
<br />
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataSourceID="SqlDataSource2" AllowPaging="True" AllowSorting="True" CellPadding="4" ForeColor="#333333" GridLines="None" >
<AlternatingRowStyle BackColor="White" />
<Columns>
<asp:BoundField DataField="firstName" HeaderText="First Name" SortExpression="firstName" />
<asp:BoundField DataField="lastName" HeaderText="Last Name" SortExpression="lastName" />
<asp:BoundField DataField="ISBN" HeaderText="ISBN" SortExpression="ISBN" />
<asp:BoundField DataField="title" HeaderText="Title" SortExpression="title" />
<asp:BoundField DataField="publisherName" HeaderText="Publisher" SortExpression="publisherName" />
<asp:BoundField DataField="price" HeaderText="Price" SortExpression="price" DataFormatString="{0:c}" >
<ItemStyle HorizontalAlign="Right" />
</asp:BoundField>
<asp:BoundField DataField="editionNumber" HeaderText="Edition" SortExpression="editionNumber" >
<ItemStyle HorizontalAlign="Right" />
</asp:BoundField>
</Columns>
<FooterStyle BackColor="#990000" Font-Bold="True" ForeColor="White" />
<HeaderStyle BackColor="#990000" Font-Bold="True" ForeColor="White" />
<PagerStyle BackColor="#FFCC66" ForeColor="#333333" HorizontalAlign="Center" />
<RowStyle BackColor="#FFFBD6" ForeColor="#333333" />
<SelectedRowStyle BackColor="#FFCC66" Font-Bold="True" ForeColor="Navy" />
<SortedAscendingCellStyle BackColor="#FDF5AC" />
<SortedAscendingHeaderStyle BackColor="#4D0000" />
<SortedDescendingCellStyle BackColor="#FCF6C0" />
<SortedDescendingHeaderStyle BackColor="#820000" />
</asp:GridView>
<br />
<br />
<span class="auto-style2">The number of books is:</span>
<asp:Label ID="Label1" runat="server" style="color: #FF0000"></asp:Label>
</div>
</form>
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.SqlClient;
using System.Data;
namespace Homemade01
{
public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
int rowCount = GridView1.Rows.Count;
Label1.Text = "Books found: " + rowCount.ToString();
}
}
}
答案 0 :(得分：1)
我终于纠正并正确运行了。我可能在一个方面对SQL DATA Source 1进行了双重编码。我使用的是Visual Studio 2012，所以如果有人在将来引用这篇文章，请记住在SQL DataSources的属性中检查事件处理程序，然后双击选中。
这对我来说是一个很大的问题，因为虽然选择的数据源是在我的c＃代码中，但它没有在CSS代码中引用。祝所有在将来遇到这个问题的人好运。这正确地返回了结果。无论您在哪个页面，该网页都应显示在下拉列表中为所选作者找到的记录总数。
这是CSS：
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs"
Inherits="Homemade01.WebForm1" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Welcome to our Master/Detail Filtering with a DropDownList example</title>
<style type="text/css">
.auto-style1 {
font-size: xx-large;
}
</style>
</head>
<body>
<form id="form1" runat="server">
<div>
<span class="auto-style1">Welcome to our Master/Detail Filtering with a DropDownList example:</span><br />
<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:ConnectionString %>" ProviderName="<%$ ConnectionStrings:ConnectionString.ProviderName %>" SelectCommand="SELECT firstName + ' ' + lastName AS FullName, lastName, authorID, firstName FROM Authors ORDER BY lastName, authorID" OnSelected="SqlDataSource1_Selected" ></asp:SqlDataSource>
<br />
Please select an author from the list:
<asp:DropDownList ID="DropDownList1" runat="server" DataSourceID="SqlDataSource1" Height="16px" Width="248px" AutoPostBack="True" DataTextField="FullName" DataValueField="authorID">
</asp:DropDownList>
<br />
<br />
<asp:SqlDataSource ID="SqlDataSource2" runat="server" ConnectionString="<%$ ConnectionStrings:ConnectionString %>" ProviderName="<%$ ConnectionStrings:ConnectionString.ProviderName %>" SelectCommand="SELECT Authors.firstName, Authors.lastName, AuthorISBN.ISBN, Titles.title, Publishers.publisherName, Titles.price, Titles.editionNumber FROM (((Authors INNER JOIN AuthorISBN ON Authors.authorID = AuthorISBN.authorID) INNER JOIN Titles ON AuthorISBN.ISBN = Titles.ISBN) INNER JOIN Publishers ON Titles.publisherID = Publishers.publisherID) WHERE (Authors.authorID = ?)" OnSelected="SqlDataSource2_Selected">
<SelectParameters>
<asp:ControlParameter ControlID="DropDownList1" Name="?" PropertyName="SelectedValue" />
</SelectParameters>
</asp:SqlDataSource>
<br />
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataSourceID="SqlDataSource2" AllowPaging="True" AllowSorting="True" CellPadding="4" ForeColor="#333333" GridLines="None" >
<AlternatingRowStyle BackColor="White" />
<Columns>
<asp:BoundField DataField="firstName" HeaderText="First Name" SortExpression="firstName" />
<asp:BoundField DataField="lastName" HeaderText="Last Name" SortExpression="lastName" />
<asp:BoundField DataField="ISBN" HeaderText="ISBN" SortExpression="ISBN" />
<asp:BoundField DataField="title" HeaderText="Title" SortExpression="title" />
<asp:BoundField DataField="publisherName" HeaderText="Publisher" SortExpression="publisherName" />
<asp:BoundField DataField="price" HeaderText="Price" SortExpression="price" DataFormatString="{0:c}" >
<ItemStyle HorizontalAlign="Right" />
</asp:BoundField>
<asp:BoundField DataField="editionNumber" HeaderText="Edition" SortExpression="editionNumber" >
<ItemStyle HorizontalAlign="Right" />
</asp:BoundField>
</Columns>
<FooterStyle BackColor="#990000" Font-Bold="True" ForeColor="White" />
<HeaderStyle BackColor="#990000" Font-Bold="True" ForeColor="White" />
<PagerStyle BackColor="#FFCC66" ForeColor="#333333" HorizontalAlign="Center" />
<RowStyle BackColor="#FFFBD6" ForeColor="#333333" />
<SelectedRowStyle BackColor="#FFCC66" Font-Bold="True" ForeColor="Navy" />
<SortedAscendingCellStyle BackColor="#FDF5AC" />
<SortedAscendingHeaderStyle BackColor="#4D0000" />
<SortedDescendingCellStyle BackColor="#FCF6C0" />
<SortedDescendingHeaderStyle BackColor="#820000" />
</asp:GridView>
<br />
<br />
<asp:Label ID="Label1" runat="server" style="color: #FF0000"></asp:Label>
</div>
</form>
现在是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.SqlClient;
using System.Data;
namespace Homemade01
{
public partial class WebForm1 : System.Web.UI.Page
{
//int rowCount;
protected void Page_Load(object sender, EventArgs e)
{
}
protected void SqlDataSource1_Selected(object sender, SqlDataSourceStatusEventArgs e)
{
//int rowCount = e.AffectedRows;
}
protected void SqlDataSource2_Selected(object sender, SqlDataSourceStatusEventArgs e)
{
int rowCount = e.AffectedRows;
//Above find the affected rows in SQL Data Source 2 and counts them then assigns them to an INT
Label1.Text = "The number of Books found is: " + rowCount.ToString();
//Label prints its text plus the rowCount variable which is converted to a string
}
}
}
答案 1 :(得分：0)
如果问题是使用SQL数据源打印绑定到网格的记录总数或行数，那么您可以尝试修改代码，如下所示。
对于SQL数据源，只要从下拉列表中选择一个值，就会发生另一个事件，即... SqlDataSource2_Selected（）。 如果您使用的是sqldatasource，则可以使用'Selected'事件计算总行数，该事件在select操作完成后被触发。
protected void SqlDataSource1_Selected(object sender, SqlDataSourceStatusEventArgs e)
{
int rowCount = e.AffectedRows;
}
您可能应该尝试将代码从page_load移动到上面的事件。