.NET 下动态设置 WebService 引用

    做需要部署 WebService 的项目时，要根据部署环境环境设置 WebService 引用。VS(2008)下可以引用 WebService 并且引用地址也设置在app.config(winform)中，但引用后生成了一堆配置文件，并且配置文件中含有引用地址，给人硬编码的错觉。如果手动引用，稍微配置可达到同样的效果。即使用 WSDL.exe 工具生成WebService的代理，本地调用即可。
有如下 WebService ：

using System;
using System.Web;
using System.Web.Services;
using System.Web.Services.Protocols;

[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
public class Service : System.Web.Services.WebService
{
    public Service () {

        //Uncomment the following line if using designed components
        //InitializeComponent();
    }

    [WebMethod]
    public int Sum(int a, int b)
    {
        int c = a + b;

        return c;
    }
    
}

 WSDL.exe 命令行为：wsdl /n:namespace1 /out:c:/service1.cs http://localhost/WebServiceHTTP/Service.asmx?WSDL
生成的代理文件内容为：

//------------------------------------------------------------------------------
// <auto-generated>
//     This code was generated by a tool.
//     Runtime Version:2.0.50727.1433
//
//     Changes to this file may cause incorrect behavior and will be lost if
//     the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------

//
// This source code was auto-generated by wsdl, Version=2.0.50727.1432.
//
namespace namespace1 {
    using System.Diagnostics;
    using System.Web.Services;
    using System.ComponentModel;
    using System.Web.Services.Protocols;
    using System;
    using System.Xml.Serialization;
    
    
    /// <remarks/>
    [System.CodeDom.Compiler.GeneratedCodeAttribute("wsdl", "2.0.50727.1432")]
    [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.ComponentModel.DesignerCategoryAttribute("code")]
    [System.Web.Services.WebServiceBindingAttribute(Name="ServiceSoap", Namespace="http://tempuri.org/")]
    public partial class Service : System.Web.Services.Protocols.SoapHttpClientProtocol {
        
        private System.Threading.SendOrPostCallback SumOperationCompleted;
        
        /// <remarks/>
        public Service() {
            this.Url = "http://localhost/WebServiceHTTP/Service.asmx";
        }
        
        /// <remarks/>
        public event SumCompletedEventHandler SumCompleted;
        
        /// <remarks/>
        [System.Web.Services.Protocols.SoapDocumentMethodAttribute("http://tempuri.org/Sum", RequestNamespace="http://tempuri.org/", ResponseNamespace="http://tempuri.org/", Use=System.Web.Services.Description.SoapBindingUse.Literal, ParameterStyle=System.Web.Services.Protocols.SoapParameterStyle.Wrapped)]
        public int Sum(int a, int b) {
            object[] results = this.Invoke("Sum", new object[] {
                        a,
                        b});
            return ((int)(results[0]));
        } 
         //还有很多...

然后把构造方法中的 this.Url = "http://localhost/WebServiceHTTP/Service.asmx"; 在app.config中配置即可。

this.Url = ConfigurationManager.AppSettings.Get("service1"); 

app.config 中的内容为：

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <appSettings>
    <add key="service1" value="http://localhost/WebServiceHTTP/Service.asmx"/>  </appSettings>
</configuration>

这样做有个缺点，就是每次修改 WebService后都要重新生成一遍，设置URL。可以调试的时候直接用VS引用，完成后手工引用即可。也可写一个批处理生成代理。也可以再写一个代理，派生自WSDL.exe生成的代理，把URL以参数的形式传到WSDL.exe生成的代理。
WSDL.exe的使用方法可参考：http://msdn2.microsoft.com/en-us/library/7h3ystb6(VS.80).aspx