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C# Code:Warum bekomme ich Null Referenz Ausnahme?
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.Data.SqlClient;
using System.Configuration;
namespace FunDepartmentStore1ASPX
{
public partial class CurrentStoreInventory : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void btnShowCurrentInventory_Click(object sender,
EventArgs e)
{
DataTable taStoreItems = new DataTable("StoreItems");
string cs = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;//Here is exception
using (SqlConnection con = new SqlConnection(cs))
{
SqlCommand cmd = new SqlCommand("SELECT * FROM StoreItems", con);
SqlDataAdapter adStoreItems = new SqlDataAdapter(cmd);
adStoreItems.Fill(taStoreItems);
for (int i = 0; i < taStoreItems.Rows.Count; i++)
{
DataRow rcdStoreItem = taStoreItems.Rows[i];
ListItem liStoreItem = new ListItem((i + 1).ToString(),rcdStoreItem["ItemNumber"].ToString());
ListBox2.Items.Add(liStoreItem);
}
}
}
}
}
XML-Datei (Datei Web.config)
<?xml version="1.0"?>
<!--
For more information on how to configure your ASP.NET application, please visit
http://go.microsoft.com/fwlink/?LinkId=169433
-->
<configuration>
<connectionStrings>
<add name="ApplicationServices" connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|\aspnetdb.mdf;User Instance=true"
providerName="System.Data.SqlClient" />
<add name="csFunDS " connectionString="Data Source=USE-PC\ROLEN_SIKHRAKAR;Initial Catalog=FunDS1;Integrated Security=True"
providerName="System.Data.SqlClient" />
<add name="DBCS " connectionString="Data Source=USE-PC\ROLEN_SIKHRAKAR;Initial Catalog=FunDS1;Integrated Security=True"
providerName="System.Data.SqlClient" />
</connectionStrings>
<system.web>
<compilation debug="true" targetFramework="4.0" />
<authentication mode="Forms">
<forms loginUrl="~/Account/Login.aspx" timeout="2880" />
</authentication>
<membership>
<providers>
<clear/>
<add name="AspNetSqlMembershipProvider" type="System.Web.Security.SqlMembershipProvider" connectionStringName="ApplicationServices"
enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="false"
maxInvalidPasswordAttempts="5" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0" passwordAttemptWindow="10"
applicationName="/" />
</providers>
</membership>
<profile>
<providers>
<clear/>
<add name="AspNetSqlProfileProvider" type="System.Web.Profile.SqlProfileProvider" connectionStringName="ApplicationServices" applicationName="/"/>
</providers>
</profile>
<roleManager enabled="false">
<providers>
<clear/>
<add name="AspNetSqlRoleProvider" type="System.Web.Security.SqlRoleProvider" connectionStringName="ApplicationServices" applicationName="/" />
<add name="AspNetWindowsTokenRoleProvider" type="System.Web.Security.WindowsTokenRoleProvider" applicationName="/" />
</providers>
</roleManager>
</system.web>
<system.webServer>
<modules runAllManagedModulesForAllRequests="true"/>
</system.webServer>
</configuration>
HTML Quelle:
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="CurrentStoreInventory.aspx.cs"
Inherits="FunDepartmentStore1ASPX.CurrentStoreInventory" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Current Store Inventory</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<table>
<tr>
<td>
<asp:Label ID="Label1" runat="server" Text="Index"></asp:Label>
</td>
<td>
<asp:Label ID="Label2" runat="server" Text="Item #"></asp:Label>
</td>
<td>
<asp:Label ID="Label3" runat="server" Text="Manufacturer"></asp:Label>
</td>
<td>
<asp:Label ID="Label4" runat="server" Text="Category"></asp:Label>
</td>
<td>
<asp:Label ID="Label5" runat="server" Text="Sub-Caregory"></asp:Label>
</td>
<td>
<asp:Label ID="Label6" runat="server" Text="Item Name/Description"></asp:Label>
</td>
<td>
<asp:Label ID="Label7" runat="server" Text="Size"></asp:Label>
</td>
<td>
<asp:Label ID="Label8" runat="server" Text="Unit Price"></asp:Label>
</td>
<td>
<asp:Label ID="Label9" runat="server" Text="Status"></asp:Label>
</td>
</tr>
<tr>
<td>
<asp:ListBox ID="ListBox1" runat="server"></asp:ListBox>
</td>
<td>
<asp:ListBox ID="ListBox2" runat="server"></asp:ListBox>
</td>
<td>
<asp:ListBox ID="ListBox3" runat="server"></asp:ListBox>
</td>
<td>
<asp:ListBox ID="ListBox4" runat="server"></asp:ListBox>
</td>
<td>
<asp:ListBox ID="ListBox5" runat="server"></asp:ListBox>
</td>
<td>
<asp:ListBox ID="ListBox6" runat="server"></asp:ListBox>
</td>
<td>
<asp:ListBox ID="ListBox7" runat="server"></asp:ListBox>
</td>
<td>
<asp:ListBox ID="ListBox8" runat="server"></asp:ListBox>
</td>
<td>
<asp:ListBox ID="ListBox9" runat="server"></asp:ListBox>
</td>
</tr>
<tr>
<td colspan="7">
<asp:Button ID="btnShowCurrentInventory" runat="server"
Text="Show Store Items Inventory" onclick="btnShowCurrentInventory_Click" />
</td>
<td colspan="2">
<asp:Button ID="btnClose" runat="server" Text="Close" />
</td>
</tr>
</table>
</div>
</form>
</body>
</html>
[1]: http://i.stack.imgur.com/gapIY.jpg
Warum bin ich in C# -Code über NULL-Verweis Ausnahme zu bekommen? Der obige Inhalt enthält folgende: - 1. C# -Code 2. XML-Datei (Web.config-Datei) 3. HTML-Quelle Kann mir bitte jemand helfen, dieses Problem zu lösen?
sein, was Linie die Ausnahme wirft? – ChrisS
Wo NULL Ausnahme erscheinen? –