功能警告 - 空引用 [英] Function Warning - Null Reference
问题描述
我收到以下警告以下功能。我理解
这意味着什么，但我如何处理空引用？然后我如何传递
结果值？
问候
警告1功能''Dec2hms''并没有在所有代码路径上返回值。使用结果时，可能会在运行时发生
null引用异常。
G：\ Project Development \ Visual Studio 2005 \Projects\Ascension\Ascension\SwephConversions .vb 64 3 Ascension
''将小数小时转换为小时/分钟/秒
公共职能Dec2hms（ByVal x As Decimal）As String
Dim hh As Int32，mm As Int32，ss As Decimal，余数为十进制
' 'Dim xa十进制，hh为整数
hh = CType（x，整数）
余数=（x - hh）
mm = CType（（余数* 60），整数）
余数=（（余数* 60） - mm）
ss = Int（余数* 60）
余数=（（余数* 60） - ss）
如果余数> = 0.5然后
ss = ss + 1
否则
ss = ss
结束如果
hms = hh& h &安培; mm& m &安培; ss& " s"
结束功能
返回hh& ; h &安培; mm& m &安培; ss& s>
" Terry" < ne ******* @ whiteHYPHENlightDOTme.ukwrote in message
news：uQ ************** @ TK2MSFTNGP02.phx.gbl ...
>我收到以下函数的以下警告。我明白这意味着什么，但我如何处理空引用？然后我如何传递
结果值？
问候
警告1功能''Dec2hms''不会在所有代码路径上返回一个值。使用结果时，可能会在运行时发生
null引用异常。
G：\ Project Development \ Visual Studio 2005 \Projects\Ascension\Ascension\SwephConversions .vb 64 3 Ascension
''将小数小时转换为小时/分钟/秒
公共函数Dec2hms（ByVal x As Decimal）As String
Dim hh As Int32，mm As Int32，ss As Decimal，余数为十进制
''Dim xa decimal，hh as integer
hh = CType（x，Integer）
余数=（x - hh ）
mm = CType（（余数* 60），整数）
余数=（（余数* 60） - mm）
ss = Int（余数* 60）
余数=（（余数* 60） - ss）
如果余数> = 0.5那么
ss = ss + 1
否则
ss = ss
结束如果
hms = hh& h &安培; mm& m &安培; ss& " s"
结束功能
Stephany Young写道：
返回hh& h &安培; mm& m &安培; ss& " s"
我不知道你在VB中有多少背景。我会假设不多。
澄清：
功能''Dec2hms''并不会在所有代码路径上返回值。意味着
一个函数可能没有沿着其中一个可执行的执行路径返回一个值，而是一行调用
$ b的代码$ b函数可以从函数中获取空指针。在VB和VB.NET中，
Sub（子例程）是一个永远不会返回值的过程。 A
函数是一个必须返回一个值的过程。
要从函数返回一个值，请使用关键字Return后跟
正在退回的价值或变量。
配售
返回hh& h &安培; mm& m &安培; ss&函数结尾处的's"
（右上方的结束函数）应解决
问题。
谢谢Stephany，
我理解你的解释以及警告的内容。为了取消警告，我需要确保函数不返回
空指针。是否有更好的语法可以提供更完整的
解决方案？
我的经验来自VBA，我刚刚开始使用VB和.NET。
结构和语法是我想要了解的。对我来说最好的方式
是要有一些好书，尝试转换一些VBA代码并访问这些
新闻组。我希望自己3年前开始。
问候
< lo ********* @ gmail.comwrote in消息
news：11 ********************** @ k58g2000hse.googlegr oups.com ...
>
Stephany Young写道：
>返回hh& h &安培; mm& m &安培; ss& " s"
我不知道你在VB中有多少背景。我会假设不多。
澄清：
功能''Dec2hms''并不会在所有代码路径上返回值。意味着
一个函数可能没有沿着其中一个可执行的执行路径返回一个值，而是一行调用
$ b的代码$ b函数可以从函数中获取空指针。在VB和VB.NET中，
Sub（子例程）是一个永远不会返回值的过程。 A
函数是一个必须返回一个值的过程。
要从函数返回一个值，请使用关键字Return后跟
正在退回的价值或变量。
配售
返回hh& h &安培; mm& m &安培; ss&函数结尾处的's"
（右上方的结束函数）应解决
问题。
I am getting the following warning for the below function. I understand what
it means but how do I handle a null reference? Then how do I pass the
resulting value?
Regards
Warning 1 Function ''Dec2hms'' doesn''t return a value on all code paths. A
null reference exception could occur at run time when the result is used.
G:\Project Development\Visual Studio
2005\Projects\Ascension\Ascension\SwephConversions .vb 64 3 Ascension
'' Convert decimal hours to hours/minutes/seconds
Public Function Dec2hms(ByVal x As Decimal) As String
Dim hh As Int32, mm As Int32, ss As Decimal, remainder As Decimal
''Dim x a decimal, hh as integer
hh = CType(x, Integer)
remainder = (x - hh)
mm = CType((remainder * 60), Integer)
remainder = ((remainder * 60) - mm)
ss = Int(remainder * 60)
remainder = ((remainder * 60) - ss)
If remainder >= 0.5 Then
ss = ss + 1
Else
ss = ss
End If
hms = hh & "h " & mm & "m " & ss & "s"
End Function
Return hh & "h " & mm & "m " & ss & "s"
"Terry" <ne*******@whiteHYPHENlightDOTme.ukwrote in message
news:uQ**************@TK2MSFTNGP02.phx.gbl...>I am getting the following warning for the below function. I understand
what it means but how do I handle a null reference? Then how do I pass the
resulting value?
Regards
Warning 1 Function ''Dec2hms'' doesn''t return a value on all code paths. A
null reference exception could occur at run time when the result is used.
G:\Project Development\Visual Studio
2005\Projects\Ascension\Ascension\SwephConversions .vb 64 3 Ascension
'' Convert decimal hours to hours/minutes/seconds
Public Function Dec2hms(ByVal x As Decimal) As String
Dim hh As Int32, mm As Int32, ss As Decimal, remainder As Decimal
''Dim x a decimal, hh as integer
hh = CType(x, Integer)
remainder = (x - hh)
mm = CType((remainder * 60), Integer)
remainder = ((remainder * 60) - mm)
ss = Int(remainder * 60)
remainder = ((remainder * 60) - ss)
If remainder >= 0.5 Then
ss = ss + 1
Else
ss = ss
End If
hms = hh & "h " & mm & "m " & ss & "s"
End Function
Stephany Young wrote:Return hh & "h " & mm & "m " & ss & "s"
I don''t know how much background you have in VB. I''ll assume not much.
To clarify:
"Function ''Dec2hms'' doesn''t return a value on all code paths." means
that a function might not be returning a value along one of its
possible paths of execution, and that a line of code that calls the
function could get a Null Pointer from the function. In VB and VB.NET,
A Sub (Subroutine) is a procedure which never returns a value. A
Function is a procedure that MUST return a value.
To return a value from a function, use the keyword Return followed by
the value or variable that is being returned.
Placing
Return hh & "h " & mm & "m " & ss & "s"
at the end of the function (right above "end function") should fix the
problem.
Thanks Stephany,
I understand your explanation and what the warning is indicating. In order
to remove the warning I would need to ensure the function does not return a
null pointer. Is there a better syntax available giving a more complete
solution?
My experience comes from VBA and I have just started out in VB and .NET. The
structure and syntax is what I am trying to understand. The best way for me
is to have some good books, try converting some VBA code and visit these
newsgroups. Just wished I started 3 years ago.
Regards
<lo*********@gmail.comwrote in message
news:11**********************@k58g2000hse.googlegr oups.com...>
Stephany Young wrote:>Return hh & "h " & mm & "m " & ss & "s"
I don''t know how much background you have in VB. I''ll assume not much.
To clarify:
"Function ''Dec2hms'' doesn''t return a value on all code paths." means
that a function might not be returning a value along one of its
possible paths of execution, and that a line of code that calls the
function could get a Null Pointer from the function. In VB and VB.NET,
A Sub (Subroutine) is a procedure which never returns a value. A
Function is a procedure that MUST return a value.
To return a value from a function, use the keyword Return followed by
the value or variable that is being returned.
Placing
Return hh & "h " & mm & "m " & ss & "s"
at the end of the function (right above "end function") should fix the
problem.
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