我接下来还是用一个例子讲解一下如何在WF 4中动态加载xaml工作流的做法吧。
1. 创建自定义的Activity
using
System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Activities;
namespace WorkflowConsoleApplication1
{
public sealed class MyActivity : CodeActivity
{
// Define an activity input argument of type string
public InArgument < string > Text { get ; set ; }
// If your activity returns a value, derive from CodeActivity<TResult>
// and return the value from the Execute method.
protected override void Execute(CodeActivityContext context)
{
// Obtain the runtime value of the Text input argument
string text = context.GetValue( this .Text);
Console.WriteLine(text);
}
}
}
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Activities;
namespace WorkflowConsoleApplication1
{
public sealed class MyActivity : CodeActivity
{
// Define an activity input argument of type string
public InArgument < string > Text { get ; set ; }
// If your activity returns a value, derive from CodeActivity<TResult>
// and return the value from the Execute method.
protected override void Execute(CodeActivityContext context)
{
// Obtain the runtime value of the Text input argument
string text = context.GetValue( this .Text);
Console.WriteLine(text);
}
}
}
2.将这个自定义的Activity添加到流程中
设置它的Text属性：
3.将工作流的属性进行一些修改
注意，将BuildAction设置为Content，同时Copy to Output Directory 设置为Copy always，并且将Custom Tool设置为空白，完成操作之后，得到的xaml文件如下：
<
Activity
mc:Ignorable
="sap"
x:Class
="WorkflowConsoleApplication1.Workflow1"
sap:VirtualizedContainerService.HintSize
="240,240"
mva:VisualBasic.Settings
="Assembly references and imported namespaces for internal implementation"
xmlns
="http://schemas.microsoft.com/netfx/2009/xaml/activities"
xmlns:local
="clr-namespace:WorkflowConsoleApplication1"
xmlns:mc
="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:mv
="clr-namespace:Microsoft.VisualBasic;assembly=System"
xmlns:mva
="clr-namespace:Microsoft.VisualBasic.Activities;assembly=System.Activities"
xmlns:s
="clr-namespace:System;assembly=mscorlib"
xmlns:s1
="clr-namespace:System;assembly=System"
xmlns:s2
="clr-namespace:System;assembly=System.Xml"
xmlns:s3
="clr-namespace:System;assembly=System.Core"
xmlns:sad
="clr-namespace:System.Activities.Debugger;assembly=System.Activities"
xmlns:sap
="http://schemas.microsoft.com/netfx/2009/xaml/activities/presentation"
xmlns:scg
="clr-namespace:System.Collections.Generic;assembly=System"
xmlns:scg1
="clr-namespace:System.Collections.Generic;assembly=System.ServiceModel"
xmlns:scg2
="clr-namespace:System.Collections.Generic;assembly=System.Core"
xmlns:scg3
="clr-namespace:System.Collections.Generic;assembly=mscorlib"
xmlns:sd
="clr-namespace:System.Data;assembly=System.Data"
xmlns:sl
="clr-namespace:System.Linq;assembly=System.Core"
xmlns:st
="clr-namespace:System.Text;assembly=mscorlib"
xmlns:x
="http://schemas.microsoft.com/winfx/2006/xaml"
>
< local:MyActivity sad:XamlDebuggerXmlReader.FileName ="D:\temp\WorkflowConsoleApplication1\WorkflowConsoleApplication1\Workflow1.xaml" sap:VirtualizedContainerService.HintSize ="200,200" Text ="Hello,World" />
</ Activity >
< local:MyActivity sad:XamlDebuggerXmlReader.FileName ="D:\temp\WorkflowConsoleApplication1\WorkflowConsoleApplication1\Workflow1.xaml" sap:VirtualizedContainerService.HintSize ="200,200" Text ="Hello,World" />
</ Activity >
4. 通过下面的代码创建并且运行流程
using
System;
using System.Linq;
using System.Activities;
using System.Activities.Statements;
using System.Activities.XamlIntegration;
namespace WorkflowConsoleApplication1
{
class Program
{
static void Main( string [] args)
{
WorkflowInvoker.Invoke(ActivityXamlServices.Load( " workflow1.xaml " ));
}
}
}
using System.Linq;
using System.Activities;
using System.Activities.Statements;
using System.Activities.XamlIntegration;
namespace WorkflowConsoleApplication1
{
class Program
{
static void Main( string [] args)
{
WorkflowInvoker.Invoke(ActivityXamlServices.Load( " workflow1.xaml " ));
}
}
}
运行上述代码，我们会遇到一个错误。
这是为什么呢？MyActivity找不到？我们应该手工将xaml文件成下面这样。请注意粗体的部分，我添加了assembly的设置：
<
Activity mc:Ignorable
=
"
sap
"
x:Class
=
"
WorkflowConsoleApplication1.Workflow1
"
sap:VirtualizedContainerService.HintSize
=
"
240,240
"
mva:VisualBasic.Settings
=
"
Assembly references and imported namespaces for internal implementation
"
xmlns
=
"
http://schemas.microsoft.com/netfx/2009/xaml/activities
"
xmlns:local
=
"
clr-namespace:WorkflowConsoleApplication1;assembly=WorkflowConsoleApplication1
"
xmlns:mc
=
"
http://schemas.openxmlformats.org/markup-compatibility/2006
"
xmlns:mv
=
"
clr-namespace:Microsoft.VisualBasic;assembly=System
"
xmlns:mva
=
"
clr-namespace:Microsoft.VisualBasic.Activities;assembly=System.Activities
"
xmlns:s
=
"
clr-namespace:System;assembly=mscorlib
"
xmlns:s1
=
"
clr-namespace:System;assembly=System
"
xmlns:s2
=
"
clr-namespace:System;assembly=System.Xml
"
xmlns:s3
=
"
clr-namespace:System;assembly=System.Core
"
xmlns:sad
=
"
clr-namespace:System.Activities.Debugger;assembly=System.Activities
"
xmlns:sap
=
"
http://schemas.microsoft.com/netfx/2009/xaml/activities/presentation
"
xmlns:scg
=
"
clr-namespace:System.Collections.Generic;assembly=System
"
xmlns:scg1
=
"
clr-namespace:System.Collections.Generic;assembly=System.ServiceModel
"
xmlns:scg2
=
"
clr-namespace:System.Collections.Generic;assembly=System.Core
"
xmlns:scg3
=
"
clr-namespace:System.Collections.Generic;assembly=mscorlib
"
xmlns:sd
=
"
clr-namespace:System.Data;assembly=System.Data
"
xmlns:sl
=
"
clr-namespace:System.Linq;assembly=System.Core
"
xmlns:st
=
"
clr-namespace:System.Text;assembly=mscorlib
"
xmlns:x
=
"
http://schemas.microsoft.com/winfx/2006/xaml
"
>
< local:MyActivity sad:XamlDebuggerXmlReader.FileName = " D:\temp\WorkflowConsoleApplication1\WorkflowConsoleApplication1\Workflow1.xaml " sap:VirtualizedContainerService.HintSize = " 200,200 " Text = " Hello,World " />
</ Activity >
< local:MyActivity sad:XamlDebuggerXmlReader.FileName = " D:\temp\WorkflowConsoleApplication1\WorkflowConsoleApplication1\Workflow1.xaml " sap:VirtualizedContainerService.HintSize = " 200,200 " Text = " Hello,World " />
</ Activity >
我个人认为这应该算是一个bug。但目前的情况就是这样，如果你的自定义Activity是在当前应用程序里面，则也是需要设置Assembly的信息的。当然，如果自定义Activity是单独的Assembly,则应该默认就会写上Assembly信息，那种情况反而是没有问题的。
