不要将服务客户端声明行作为类字段， 中使用的每个方法都创建实例。 这样问题就会解决。如果您将服务客户端实例创建为类字段，则会出现设计时错误!

我也有同样的问题。我在类库中使用WCF服务，并从windows应用程序项目调用类库。但我是忘记改变<系统。serviceModel>在windows应用程序项目的配置文件中。类库app.Config文件的serviceModel>。 解决方案:将外部项目的配置与类库的wcf配置相同。

在测试了几个选项之后，我最终通过使用

contract=“IMySOAPWebService”

例如，在配置中没有完整的命名空间。由于某种原因，全名没有正确解析

对使用服务的非库应用程序进行单元测试可能会导致此问题。

The information that others have entered addresses the root cause of this. If you are trying to write automated test cases and the unit you are testing will actually invoke the service interface, you need to add the service reference to the test project. This is a flavor of the application using library type of error. I did not immediately realize this though because my code that consumes the interface is not in a library. However, when the test actually runs it will be running from the test assembly, not the assembly under test.

向单元测试项目添加服务引用解决了我的问题。

我通过自己创建绑定和端点地址实例解决了这个问题(我认为其他人可能已经建议了)——因为我不想向配置文件添加新的设置(这是对一些广泛使用的现有库代码的替换，以前使用的是旧的Web Service Reference等)，所以我希望能够在不添加新的配置设置的情况下将其放入。

var remoteAddress = new System.ServiceModel.EndpointAddress(_webServiceUrl);

using (var productService = new ProductClient(new System.ServiceModel.BasicHttpBinding(), remoteAddress))
{
    //set timeout
    productService.Endpoint.Binding.SendTimeout = new TimeSpan(0,0,0,_webServiceTimeout);

    //call web service method
    productResponse = productService.GetProducts();
} 

Edit

如果你正在使用https，那么你需要使用BasicHttpBinding而不是BasicHttpBinding。

There seem to be several ways to create/fix this issue. For me, the CRM product I am using was written in native code and is able to call my .NET dll, but I run into the configuration information needing to be at/above the main application. For me, the CRM application isn't .NET, so I ended up having to put it in my machine.config file (not where I want it). In addition, since my company uses Websense I had a hard time even adding the Service Reference due to a 407 Proxy Authentication Required issue, that to required a modification to the machine.cong.

代理解决方案:

为了让WCF服务引用工作，我必须从我的DLL的app.config复制信息到主应用程序配置(但对我来说是machine.config)。我还必须将端点信息复制到同一个文件中。一旦我这么做了，它就开始为我工作了。