1. nuget中加两个引用，注意：一定是要4.10.3这个版本，最新的10版本不行
<PackageReference Include="System.ServiceModel.Http" Version="4.10.3" />
<PackageReference Include="System.ServiceModel.Primitives" Version="4.10.3" />
2. 生成包装类，注意所指定的namespace，指令生成一个Reference.cs文件

net8调用webservice.ServiceReference2.WebService1SoapClient c = new net8调用webservice. ServiceReference2.WebService1SoapClient(net8调用webservice.ServiceReference2.WebService1SoapClient.EndpointConfiguration.WebService1Soap12);
byte[] buf = System.Text.UTF8Encoding.UTF8.GetBytes("abca中楞");
var t = await c.HelloWorld2Async("abc在", buf);
this.textBox1.Text = t.Body.HelloWorld2Result;