/// <summary>
/// Overridden to validate the activity properties and populate the error collection.
/// Only one child activity is allowed. If multiple acitivties need to be executed,
/// place them in a sequence or other appropriate composite activities.
/// </summary>
/// <param name="manager"></param>
/// <param name="obj"></param>
/// <returns></returns>
public override ValidationErrorCollection Validate(ValidationManager manager, object obj)
{
ValidationErrorCollection validationErrors = new ValidationErrorCollection(base.Validate(manager, obj));
ForEach foreachActivity = obj as ForEach;
if (foreachActivity == null)
{
throw new ArgumentException("Validate parameter 'obj' is not a ForEach activity.");
}
if (foreachActivity.EnabledActivities.Count > 1)
{
validationErrors.Add(new ValidationError("Only one child is allowed in the ForEach activity.", InvalidNumberOfChildren));
}
return(validationErrors);
}
// When a child activity is closed, it's removed from the execution context,
// and the execution proceed to the next iteration.
private void OnChildClose(Object sender, ActivityExecutionStatusChangedEventArgs e)
{
if (e == null)
{
throw new ArgumentNullException("OnChildClose parameter 'e' is null.");
}
if (sender == null)
{
throw new ArgumentNullException("OnChildClose parameter 'sender' is null.");
}
ActivityExecutionContext context = sender as ActivityExecutionContext;
if (context == null)
{
throw new ArgumentException("OnChildClose parameter 'sender' is not ActivityExecutionContext.");
}
ForEach foreachActivity = context.Activity as ForEach;
if (foreachActivity == null)
{
throw new ArgumentException("OnChildClose parameter 'sender' does not contain a 'ForEach' activity.");
}
// Remove the event handler first.
e.Activity.Closed -= this.OnChildClose;
// Then remove the child activity from the execution context.
context.ExecutionContextManager.CompleteExecutionContext(context.ExecutionContextManager.GetExecutionContext(e.Activity));
// Move on to the next iteration.
if (this.ExecutionStatus == ActivityExecutionStatus.Canceling)
{
context.CloseActivity();
}
else if (this.ExecutionStatus == ActivityExecutionStatus.Executing)
{
if (!ExecuteNext(context))
{
context.CloseActivity();
}
}
}