类型为"System.Data.SqlClient.SqlException"实例失败的异常

Question

我是C#的初学者，我正在使用Web服务。当我尝试测试我的服务时，出现以下错误消息：

System.Data 中发生类型为"System.InvalidOperationException"的异常.dll但未在用户代码中处理

附加信息：实例故障。

这是我在 Web 配置中的连接字符串：

<connectionStrings>
<add name="connection" 
connectionString="Data Source=DESKTOP-CIRUCVV\SQLEXPRESS;Initial Catalog=CustomerManagerment;Integrated Security=True;"/>
</connectionStrings>

这是我在 Web 服务类中的代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Data.SqlClient;
using System.Data;
using System.Web.Configuration;
namespace WebService
{
/// <summary>
/// Summary description for CustomerService
/// </summary>
[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
[System.ComponentModel.ToolboxItem(false)]
// To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line. 
// [System.Web.Script.Services.ScriptService]
public class CustomerService : System.Web.Services.WebService
{
static string strcon = WebConfigurationManager.ConnectionStrings["connection"].ConnectionString;
public CustomerService() { }
[WebMethod(Description = "Show Customers")]
public DataSet showCustomer() 
{
SqlConnection con = new SqlConnection(strcon);
string Sql = "select * from Customers";
SqlDataAdapter da = new SqlDataAdapter(Sql, con);
DataSet ds = new DataSet();
da.Fill(ds);
return ds;
}
}
}

Answer 1

将DESKTOP-CIRUCVV\SQLEXPRESS更改为DESKTOP-CIRUCVVSQLEXPRESS