并非所有的代码路径都返回值
public DateTime UpdateAndInsert(Guid OverTimeHeadId, int OverTimeStatusId, Guid UserId,DateTime CreateTimeId,Guid guidId)
{
using (TransactionScope ts = new TransactionScope())//两个一起执行
{
string strSql = "UPDATE OverTimeHead SET OverTimeStatusId = '{1} ' WHERE (OverTimeHeadId = '{0} ') ";

new CommonData().ExeNonQuery(strSql);

strSql = "INSERT INTO OverTimeFlows ( UserId, OverTimeStatusId,OverTimeFlowsId,CreateDateTime) VALUES ( '{2} ', '{1} ', '{4} ', '{3} ') ";


new CommonData().ExeNonQuery(strSql);

ts.Complete();
}
}

[解决办法]
你声明的类命是要返回一个DateTime 啊


return ...
[解决办法]
都没有return一个值呢!
[解决办法]
你不要return 什么..干吗构造方法时声明了返回值..去掉..改void不就好了?
[解决办法]
public void UpdateAndInsert(Guid OverTimeHeadId, int OverTimeStatusId, Guid UserId,DateTime CreateTimeId,Guid guidId)
{
using (TransactionScope ts = new TransactionScope())//两个一起执行
{
string strSql = "UPDATE OverTimeHead SET OverTimeStatusId = '{1} ' WHERE (OverTimeHeadId = '{0} ') ";

new CommonData().ExeNonQuery(strSql);

strSql = "INSERT INTO OverTimeFlows ( UserId, OverTimeStatusId,OverTimeFlowsId,CreateDateTime) VALUES ( '{2} ', '{1} ', '{4} ', '{3} ') ";


new CommonData().ExeNonQuery(strSql);

ts.Complete();
}
}
[解决办法]
public DateTime UpdateAndInsert

这个函数要示有返回值 DateTime

这样声明就可以无返回值了：public void UpdateAndInsert