Boolean

[shapper]

Hi,

I have the following code line:
(string)ViewData["Tags"] ?? ViewData.Model.Tags.ToString()

How can I do something similar for a boolean type variable. I tried:
(bool)ViewData["IsPublished"] ?? ViewData.Model.IsPublished

However it says ?? cannot be used with boolean type variable.

Thanks,
Miguel

[=?ISO-8859-1?Q?Arne_Vajh=F8j?=]

shapper wrote:

I have the following code line:
(string)ViewData["Tags"] ?? ViewData.Model.Tags.ToString()

How can I do something similar for a boolean type variable. I tried:
(bool)ViewData["IsPublished"] ?? ViewData.Model.IsPublished

However it says ?? cannot be used with boolean type variable.

Because bool can not be null then the ?? operation does
not make much sense.

Arne

[Hans Kesting]

shapper wrote on 21-8-2008 :

Hi,

I have the following code line:
(string)ViewData["Tags"] ?? ViewData.Model.Tags.ToString()

How can I do something similar for a boolean type variable. I tried:
(bool)ViewData["IsPublished"] ?? ViewData.Model.IsPublished

However it says ?? cannot be used with boolean type variable.

Thanks,
Miguel

Try this:
ViewData["IsPublished"] as bool? ?? ViewData.Model.IsPublished

the "as bool?" part tries to cast ViewData["IsPublished"] to a nullable
bool, which will return null (instead of a cast exception) on failure.
The "??" part will convert the null to the result of IsPublished.
Note: the result-type of this expression is "bool" (assuming
IsPublished returns a bool) and not "bool?".

Hans Kesting