定义接口，该接口由为表达式计算提供上下文帧的工作流表达式计算组件实现。
Defines the interface implemented by the workflow expression evaluation component that provides a context frame for expression evaluation.
NETFX4里的WF包括可组装的工作流style，统一的规则和行为，以及改进的数据绑定、定界和表达式支持。
WF in.net FX 4 includes a composable set of workflow styles, a unification of rules and activities as well as improved data binding, scoping, and expression support.
序列表达式与异步工作流一样，都是计算表达式的示例。
Sequence expressions are an example of a computation expression, as are asynchronous workflows.
序列表达式与异步工作流一样，都是计算表达式的示例。
Sequence expressions are an example of a computation expression, as are asynchronous workflows.
应用推荐