Microsoft CRM workflow code activity to retrieve various useful parameters for the current executing context.

GetEntityParametersCodeActivity.cs

public class GetEntityParametersCodeActivity : CodeActivity
{
    [Output("PrimaryEntityID")]
    [ArgumentDescription("Primary Entity ID.")]
    public OutArgument<string> PrimaryEntityId { get; set; }

    [Output("PrimaryEntityName")]
    [ArgumentDescription("Primary Entity Name.")]
    public OutArgument<string> PrimaryEntityName { get; set; }
        
    [Output("SecondaryEntityName")]
    [ArgumentDescription("Secondary Entity Name.")]
    public OutArgument<string> SecondaryEntityName { get; set; }

    [Output("Request Id")]
    [ArgumentDescription("Request ID.")]
    public OutArgument<string> RequestId { get; set; }

    [Output("Correlation Id")]
    [ArgumentDescription("Correlation ID.")]
    public OutArgument<string> CorrelationId { get; set; }

    [Output("InitiatingUser Id")]
    [ArgumentDescription("InitiatingUser ID.")]
    public OutArgument<string> InitiatingUserId { get; set; }

    [Output("Operation Id")]
    [ArgumentDescription("Operation ID.")]
    public OutArgument<string> OperationId { get; set; }

    protected override void Execute(CodeActivityContext executionContext)
    {
        //Create the workflow context
        IWorkflowContext context = executionContext.GetExtension<IWorkflowContext>();
        if (context == null)
            throw new InvalidPluginExecutionException("Failed to retrieve workflow context.");
            
        //Save off the values
        PrimaryEntityId.Set(executionContext, context.PrimaryEntityId.ToString());

        if(context.RequestId.HasValue)
            RequestId.Set(executionContext, context.RequestId.Value.ToString());

        PrimaryEntityName.Set(executionContext, context.PrimaryEntityName);
        SecondaryEntityName.Set(executionContext, context.SecondaryEntityName);
        CorrelationId.Set(executionContext, context.CorrelationId.ToString());
        InitiatingUserId.Set(executionContext, context.InitiatingUserId.ToString());
        OperationId.Set(executionContext, context.OperationId.ToString());
    }
}