存在的Null值/ Nothing /“"”或不 [英] The Presents of Null values/Nothing/"" or not
问题描述
我正在尝试检查空值的呈现或空值不存在
。我的示例代码如下:
如果EmailAddresses什么都没有那么
SendMailMessage(EmailAddresses,AlertTitle,
ViolationBody)
结束如果
以上代码在检查空礼物时是否有效
值/ Nothing /""。
但是,我想检查null是否存在,即
如果EmailAddresses不是什么,那么
SendMailMessage(EmailAddresses,AlertTitle,
ViolationBody)
结束如果
以上代码无法编译。
基本上我想知道什么时候出现空值而不存在。
谢谢
I''m trying to check for the presents of null values or null value not being
present. My sample code below:
If EmailAddresses Is Nothing Then
SendMailMessage(EmailAddresses, AlertTitle,
ViolationBody)
End If
The above code works when checking for the presents of a null
value/Nothing/"".
However, I want to check for null not being present ie.
If EmailAddresses not Nothing Then
SendMailMessage(EmailAddresses, AlertTitle,
ViolationBody)
End If
The above code will not compile.
Basically I want to know when nulls are present and not present.
Thanks
推荐答案
如果EmailAddresses不是Nothing那么
将以上内容更改为:
如果不是EmailAddresses什么都没有呢
SendMailMessage(EmailAddresses,AlertTit le,
ViolationBody)
结束如果
If EmailAddresses not Nothing Then
Change the above to:
If Not EmailAddresses Is Nothing Then
SendMailMessage(EmailAddresses, AlertTitle,
ViolationBody)
End If
Imran。
Imran.
我在下面尝试了你的例子结果是一样的。它执行
发送,当EmailAddresses的值为空值(字符串)或不为空时
值,这意味着它包含一个电子邮件地址。
我可以在这里遗漏一些东西。如果没有电子邮件地址,那么没有
需要发送邮件。
谢谢
" Imran Koradia"写道:
I tried your example below and the results are the same. It executes the
send when the value of EmailAddresses is a null value (string) or not null
value which means it contains an email address.
Could I be missing something here. If there is no email address then no
need to send mail.
Thanks
"Imran Koradia" wrote:
如果EmailAddresses不是Nothing那么
If EmailAddresses not Nothing Then
将上述内容改为:
如果不是电子邮件地址则没有那么
Change the above to:
If Not EmailAddresses Is Nothing Then
SendMailMessage(EmailAddresses,AlertTitle,
ViolationBody)
结束如果
SendMailMessage(EmailAddresses, AlertTitle,
ViolationBody)
End If
Imran。
Imran.
你没有提到EmailAddresses在你的第一篇文章中是一个字符串(或
可能我读了一半:))。我以为它是一个对象(这就是为什么你的b
$ b为什么都没有测试)。为了测试字符串是否为空("),
你应该使用它:
如果EmailAddresses.Length> 0然后
''它是一个非空字符串
SendMailMessage(EmailAddresses,AlertTitle,ViolationBody)
结束如果
希望有所帮助..
Imran。
" Larry Bird" <拉******* @ discussions.microsoft.com>在消息中写道
新闻:9A ********************************** @ microsof t.com ...
You didn''t mention EmailAddresses was a string in your first post (or
probably I half read it :)). I assumed it was an object (which is why you
were testing for nothing). To test whether a string is empty ("") or not,
you should use this:
If EmailAddresses.Length > 0 Then
'' Its a non-empty string
SendMailMessage(EmailAddresses, AlertTitle, ViolationBody)
End If
hope that helps..
Imran.
"Larry Bird" <La*******@discussions.microsoft.com> wrote in message
news:9A**********************************@microsof t.com...
我在下面尝试了你的例子,结果是一样的。当EmailAddresses的值为空值(字符串)或非空值时,它执行
发送值,这意味着它包含一个电子邮件地址。
我可以在这里遗漏一些东西吗? 。如果没有电子邮件地址,则无需发送邮件。
谢谢
" Imran Koradia"写道:
I tried your example below and the results are the same. It executes the
send when the value of EmailAddresses is a null value (string) or not null
value which means it contains an email address.
Could I be missing something here. If there is no email address then no
need to send mail.
Thanks
"Imran Koradia" wrote:
如果EmailAddresses不是Nothing那么
If EmailAddresses not Nothing Then
将上述内容改为:
如果不是电子邮件地址则没有那么
Change the above to:
If Not EmailAddresses Is Nothing Then
SendMailMessage(EmailAddresses,AlertTitle,
ViolationBody)
结束如果
SendMailMessage(EmailAddresses, AlertTitle,
ViolationBody)
End If
Imran。
Imran.
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