WF工作流与Web服务的相互调用 —— WF与WCF互相调用（利用ReceiveActivity把WF发布为WCF)
前几篇文章已经为大家介绍过Web服务与Workflow工作流之间的相互调用的方法，在这两篇文章里面开始为大家介绍一下WCF与 Workflow工作流之间的关系。微软在WCF和WF之间扩展了强大的功能，使用两者能够协调工作，在.NET Framework3.5中既可以把Workflow发布为WCF实现工作流服务，也可以在WCF中调用Workflow工作流，增强其使用的灵活性。
下面先为大家介绍如何把Workflow工作流发布为WCF服务,这里还是以最简单的Hello World为例子。
首先设定一个服务契约接口
View Code
namespace
Microsoft.IService
{
[ServiceContract(SessionMode
=
SessionMode.NotAllowed)]
//
这里先使用最简单的无状态服务为例子
public
interface
IWorkflowService
{
[OperationContract]
string
Hello(
string
name);
}
}
现在新建一个Workflow，加入ReceiveActivity活动receiveActivity1，ReceiveActivity实现了 IEventActivity，可以作为EventDrivenActivity的第一个子活动,然后在receiveActivity1中加入 codeActivity1来执行操作。
现在先把receiveActivity1属性ServiceOperationInfo绑 定为刚设定的服务接口Microsoft.ISercive.IWorkflowService,在后台添加两个变量_returnValue和name 分别用来绑定返回值和输入参数。
然后把receiveActivity1的属性CanCreateInstance设置为True，这代表着每次被客户端调用的时候都创建一个新的对象实例。
现在应该为codeActivity1添加ExecuteCode事件的方法codeActivity1_ExecuteCode，下面为这个Workflow的完整代码。
View Code
namespace
Microsoft.Workflow
{
public
sealed
partial
class
Workflow4 : SequentialWorkflowActivity
{
public
string
_name;
public
string
returnValue;
public
Workflow4()
{
InitializeComponent();
}
private
void
codeActivity1_ExecuteCode(
object
sender, EventArgs e)
{
returnValue
=
"
Hello
"
+
_name;
}
}
}
现在可以为这个服务建立一个*.svc文件了，注意Service用于绑定此Workflow类文件的全名称
<%@ ServiceHost Language="C#" Debug="true" Service="Microsoft.Workflow.Workflow4 " Factory="System.ServiceModel.Activation.WorkflowServiceHostFactory" %>
然后实现*.config配置
View Code
<
configuration
>
<
system.serviceModel
>
<
behaviors
>
<
serviceBehaviors
>
<
behavior name
=
"
ServiceBehavior
"
>
<
serviceMetadata httpGetEnabled
=
"
true
"
/>
<
serviceDebug includeExceptionDetailInFaults
=
"
false
"
/>
</
behavior
>
</
serviceBehaviors
>
</
behaviors
>
<
services
>
<
service behaviorConfiguration
=
"
ServiceBehavior
"
name
=
"
Microsoft.Workflow.Workflow4
"
>
<
endpoint address
=
""
binding
=
"
wsHttpBinding
"
contract
=
"
Microsoft.IService.IWorkflowService
"
>
//
注意service Name是此Workflow工作流的全名称，而contract是该服务契约的全名称
<
identity
>
<
dns value
=
"
localhost
"
/>
</
identity
>
</
endpoint
>
<
endpoint address
=
"
mex
"
binding
=
"
mexHttpBinding
"
contract
=
"
IMetadataExchange
"
/>
</
service
>
</
services
>
</
system.serviceModel
>
</
configuration
>
现在服务器端的开发已经完成，可以开发一个客户端进行测试。我们在客户端引用此Web服务，然后配置好.config文件。
View Code
<
configuration
>
<
system.serviceModel
>
<
bindings
>
<
wsHttpBinding
>
//
添加服务绑定配置，设置其接收时间，事务，最大接收量等等属性
<
binding name
=
"
WSHttpBinding_IWorkflowService
"
closeTimeout
=
"
00:01:00
"
openTimeout
=
"
00:01:00
"
receiveTimeout
=
"
00:10:00
"
sendTimeout
=
"
00:01:00
"
bypassProxyOnLocal
=
"
false
"
transactionFlow
=
"
false
"
hostNameComparisonMode
=
"
StrongWildcard
"
maxBufferPoolSize
=
"
524288
"
maxReceivedMessageSize
=
"
65536
"
messageEncoding
=
"
Text
"
textEncoding
=
"
utf-8
"
useDefaultWebProxy
=
"
true
"
allowCookies
=
"
false
"
>
<
readerQuotas maxDepth
=
"
32
"
maxStringContentLength
=
"
8192
"
maxArrayLength
=
"
16384
"
maxBytesPerRead
=
"
4096
"
maxNameTableCharCount
=
"
16384
"
/>
<
reliableSession ordered
=
"
true
"
inactivityTimeout
=
"
00:10:00
"
enabled
=
"
false
"
/>
<
security mode
=
"
Message
"
>
<
transport clientCredentialType
=
"
Windows
"
proxyCredentialType
=
"
None
"
realm
=
""
/>
<
message clientCredentialType
=
"
Windows
"
negotiateServiceCredential
=
"
true
"
algorithmSuite
=
"
Default
"
/>
</
security
>
</
binding
>
</
wsHttpBinding
>
</
bindings
>
<
client
>
//
绑定其地址，服务契约等等属性
<
endpoint address
=
"
http://leslie-pc:5600/Service.svc
"
binding
=
"
wsHttpBinding
"
bindingConfiguration
=
"
WSHttpBinding_IWorkflowService
"
contract
=
"
ServiceReference1.IWorkflowService
"
name
=
"
WSHttpBinding_IWorkflowService
"
>
<
identity
>
<
dns value
=
"
localhost
"
/>
</
identity
>
</
endpoint
>
</
client
>
</
system.serviceModel
>
</
configuration
>
测试
View Code
static
void
Main(
string
[] args)
{
try
{
WorkflowService.WorkflowServiceClient workflowService1
=
new
WorkflowService.WorkflowServiceClient();
workflowService1.Hello(
"
Leslie
"
);
}
catch
(Exception ex)
{...}
Console.ReadKey();
}
结果显示：
Hello Leslie
经过简单的测试，证明此工作流服务已经能正常运行。使用此方式，可以轻松地Workflow发布为WCF服务而不需要编写任何干预探测代码，但值得注意的是WCF支持请求/响应，单向，双向多个工作模式，但Workflow工作流则只支持请求/响应这种模式。
微软一开始就注意把WCF与WF结合开发实现简单的相互调用，在下一篇文章将为你介绍一下如何使用SendActivity在Workflow工作流里面直接调用WCF服务。
WF工作流与Web服务的相互调用 —— 通过Web服务调用Workflow工作流（基础实例）
WF工作流与Web服务的相互调用 —— 通过Web服务调用Workflow工作流（开发持久化工作流）
WF工作流与Web服务的相互调用 —— 以InvokeWebServiceActivity在Workflow工作流调用Web服务
WF工作流与Web服务的相互调用 —— WF与WCF互相调用（利用ReceiveActivity把WF发布为WCF)