字符串变量不取值 [英] string variable not taking values

问题描述

你好！！！
我有一个字符串varibale y.i给它分配了一些值，但是使用断点显示时什么也没给我显示.

我已经尝试过使用此

Hello!!!
I have a string varibale y.i am assigning it some values but it''s showing me nothing when seen using breakpoint.

I have tried using this

Dim y As String = ""
       y = String.Format("Select orderNo, Conver(nvarchar,orderDt,106) as orderDt,LvDays,Convert(nvarchar,leave_from,106) as leave_from,Convert(nvarchar,leave_to,106) as leave_to from leave_Taken where empId={0} and lvType ='EL' and DATEPART(YEAR,orderDt)<'" + nxtyear + "' order by DATEPART(YEAR,orderDt),DATEPART(MONTH,orderDt),DATEPART(DAY,orderDt) ", eid)

并使用此

and using this

y = "Select orderNo, Conver(nvarchar,orderDt,106) as orderDt,LvDays,Convert(nvarchar,leave_from,106) as leave_from,Convert(nvarchar,leave_to,106) as leave_to from leave_Taken where empId=" + eid + " and lvType ='EL' and DATEPART(YEAR,orderDt)<'" + nxtyear + "' order by DATEPART(YEAR,orderDt),DATEPART(MONTH,orderDt),DATEPART(DAY,orderDt) "

但是当我使用断点查看它时，它仅显示".请告诉我出什么问题了！!!!

but when i am seeing it using breakpoint it shows me "" only. Please tell me whats wrong !!!

推荐答案

您尚未执行带有String.Format的行-断点在执行该行之前停止，不会.
只需执行一次，它就会出现.

顺便说一句:如果要使用String.Format(这是一个很好的主意)，为什么不正确使用它呢?

You haven''t executed the line with the String.Format on it yet - breakpoints stop before the line is executed, not after.
Single step once, and it will appear.

BTW: it you are going to use String.Format (and it is a very good idea) why not use it properly?

y = String.Format("Select orderNo, Conver(nvarchar,orderDt,106) as orderDt,LvDays,Convert(nvarchar,leave_from,106) as leave_from,Convert(nvarchar,leave_to,106) as leave_to from leave_Taken where empId={0} and lvType =''EL'' and DATEPART(YEAR,orderDt)<''" + nxtyear + "'' order by DATEPART(YEAR,orderDt),DATEPART(MONTH,orderDt),DATEPART(DAY,orderDt) ", eid)

成为

Becomes

y = String.Format("Select orderNo, Conver(nvarchar,orderDt,106) as orderDt,LvDays,Convert(nvarchar,leave_from,106) as leave_from,Convert(nvarchar,leave_to,106) as leave_to from leave_Taken where empId={0} and lvType =''EL'' and DATEPART(YEAR,orderDt)<''{1}'' order by DATEPART(YEAR,orderDt),DATEPART(MONTH,orderDt),DATEPART(DAY,orderDt) ", eid, nxtyear)

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