WWF Essay 2

Workflow in WF has three creation modes:

OnlyCode,Code Separation,No code

Code only: This is the default creation mode.

Code Separation: This method of workflow serialization is stored in a file with the. xoml extension, and its code is saved in. xoml. CS .. Xoml is a markup language of workflow, and. XAML has the same syntax. Some people may ask why there are two file names in the same format. xoml uses its own syntax before it starts to match. the same as the XAML, which is used for historical reasons. xoml is used in WPF. XAML: When you add different types of files, it will call the unused designer. The Code-separated workflow must be compiled and cannot be directly loaded to the runtime engine of the workflow.

No code: By using scalable applicationsProgramThe markup language (XAML) creates a markup source file to create the declarative method of the workflow. This method is not directly supported by Visual Studio. You can add the Code Section (. xoml. CS) delete or directly create an XML file and change the extension. xoml. This method allows you to directly load data to the workflow runtime engine during running, increasing flexibility. This method can be usedX: CodeThe instruction element inserts the process code into the workflow Tag file. The code must be in the CDATA section so that the compiler can compile the code rather than regard it as a declarative XAML flag. 【<! [CDATA [ ]

Visualized workflow and activity designer

It mainly includes a sequence workflow and a state machine workflow designer. Each type has a design view, error handling view, and canceling the processing view.

Dependencyobject)

Dependency Property is a special type of property provided by WF. It has three types of dependency properties: instance property, metadata property, and additional property.

Metadata: The value of the metadata attribute must be specified at design time and cannot be changed at runtime. In this way, metadata attributes cannot be bound.Metadata.

Instance attributes: You can use activity data binding to set the value, whether at design or runtime. This attribute can be assigned.ActivitybindInstead of the actual value.

Additional attributes: We can attach a dependency attribute to any object inherited from dependencyobject. in other words, we can use custom attributes to expand all windows workflow activities at runtime. if the parent activity needs to append information for each sub-activity, the additional attributes will be used. the standard activity provided by WF has a typical example: conditionedactivitygroup activity. it can execute one or more sub-activities with conditions, because it appends the when condition to each sub-activity. in the workflow designer, each sub-activity of the CAG displays its own when attribute.