Windows Workflow Foundation Data Model

The Windows Workflow Foundation data model is composed of three concepts: variables, arguments, and expressions. Variables represent the storage of data and arguments represent the flow of data into and out of an activity. Arguments are bound (assigned a value) using expressions that may reference variables.

In This Section

Variables and Arguments.
Describes the concepts of variables and arguments and how they are used.

Describes expressions and how they are used in workflow development.

C# Expressions
Describes C# expressions in workflows, introduced with .NET Framework 4.5.

Properties vs. Arguments
Describes how to select which type to use for activity input.

Exposing data with CacheMetadata
Describes how to expose a custom set of metadata about an executing activity's members.