//获取当前节点的上一个节点实例
ActivityInstanceBase IProcessService.GetPreviousActivityInstance(Process process)
{
var current = process.GetCurrentNode();
//将会获取到所有节点实例，应按倒序获取当前运行中的
var all = _repository.FindAllActivityInstances(process).OrderByDescending(o => o.CreateTime);
//时间倒序查找第一个不等于当前节点的节点实例
foreach (var i in all)
{
if (i.FlowNodeIndex != current)
{
return(i);
}
}
return(null);
}
