首页 > 编程开发 > Objective-C编程 >
-
WF4.0 Beta2 关于动态保存和装载XAML工作流
1.ActivityXamlServices类的主要功能是从XAML文件创建活动树的实例。提供了下面四个方法：
CreateBuilderReader：Overloaded. Maps an x:Class activity tree to an ActivityBuilder or ActivityBuilder<(Of <(TResult>)>).
CreateBuilderWriter：Maps an ActivityBuilder or ActivityBuilder<(Of <(TResult>)>) from the specified writer to an
x:Class activity tree.
CreateReader：Overloaded. Maps an x:Class activity tree to an DynamicActivity or DynamicActivity<(Of <(TResult>)>).
Load：Overloaded. Creates an instance of a declarative workflow.
Load方法遇到标记有<Activity x:Class的XAML会返回一个DynamicActivity.
2.下面一个具体的例子：
ActivityBuilder ab1 = new ActivityBuilder();
ab1.Name = "HelloWorldCary";
ab1.Properties.Add(new DynamicActivityProperty { Name = "input1", Type = typeof(InArgument<string>) });
ab1.Properties.Add(new DynamicActivityProperty { Name = "input2", Type = typeof(InArgument<string>) });
ab1.Properties.Add(new DynamicActivityProperty { Name = "output", Type = typeof(OutArgument<string>) });
ab1.Implementation = new Sequence
{
Activities =
{
new WriteLine{Text="Getting Started"},
new Delay{Duration=TimeSpan.FromSeconds(4)},
new WriteLine{Text=new VisualBasicValue<string>{ExpressionText="input1+input2"}},
new Assign<string>{To=new VisualBasicReference<string>{ExpressionText="output"},
Value=new VisualBasicValue<string>{ExpressionText="input1+input2+\" that's ok!\""}}
}
};
StringBuilder sb = new StringBuilder();
StringWriter tw = new StringWriter(sb);
XamlWriter xw = ActivityXamlServices.CreateBuilderWriter(new XamlXmlWriter(tw,new XamlSchemaContext()));
XamlServices.Save(xw,ab1);
string serializedAB = sb.ToString();
DynamicActivity da2 = ActivityXamlServices.Load(new StringReader(serializedAB)) as DynamicActivity;
var result = WorkflowInvoker.Invoke(da2, new Dictionary<string, object> { {"input1","hello"},{"input2","world"}});
Console.WriteLine("result text is {0}",result["output"]);
ActivityBuilder ab = XamlServices.Load(
ActivityXamlServices.CreateBuilderReader(
new XamlXmlReader(new StringReader(serializedAB)))) as ActivityBuilder;
Console.WriteLine("there are {0} arguments in the activity builder",ab.Properties.Count);
Console.WriteLine("press enter to exit");
Console.WriteLine(sb.ToString());
Console.ReadLine();
3.执行的结果如下：
--------------------------------------------------------------------------------------------
Getting Started
helloworld
result text is helloworld that's ok!
there are 3 arguments in the activity builder
press enter to exit
--------------------------------------------------------------------------------------------
4.生成的XAML如下：
<?xml version="1.0" encoding="utf-16"?>
<Activity x:Class="HelloWorldCary" xmlns="http://schemas.microsoft.com/netfx/2009/xaml/activities"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<x:Members>
<x:Property Name="input1" Type="InArgument(x:String)" />
<x:Property Name="input2" Type="InArgument(x:String)" />
<x:Property Name="output" Type="OutArgument(x:String)" />
</x:Members>
<Sequence>
<WriteLine Text="Getting Started" />
<Delay Duration="00:00:04" />
<WriteLine Text="[input1+input2]" />
<Assign x:TypeArguments="x:String" To="[output]" Value="[input1+input2+" that's ok!"]" />
</Sequence>
</Activity>
3.执行的结果如下：
--------------------------------------------------------------------------------------------
Getting Started
helloworld
result text is helloworld that's ok!
there are 3 arguments in the activity builder
press enter to exit
--------------------------------------------------------------------------------------------
4.生成的XAML如下：
<?xml version="1.0" encoding="utf-16"?>
<Activity x:Class="HelloWorldCary" xmlns="http://schemas.microsoft.com/netfx/2009/xaml/activities"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<x:Members>
<x:Property Name="input1" Type="InArgument(x:String)" />
<x:Property Name="input2" Type="InArgument(x:String)" />
<x:Property Name="output" Type="OutArgument(x:String)" />
</x:Members>
<Sequence>
<WriteLine Text="Getting Started" />
<Delay Duration="00:00:04" />
<WriteLine Text="[input1+input2]" />
<Assign x:TypeArguments="x:String" To="[output]" Value="[input1+input2+" that's ok!"]" />
</Sequence>
</Activity>
