cannot convert from 'System.IntPtr' to 'int'

mp

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Sep 28, 2010, 11:00:40 AM9/28/10

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I get the error in the subject line from the following line of code:
SubentityId subEnt =

new SubentityId(SubentityType.Null, System.IntPtr.Zero);

the second argument of that method is defined as Int.

this code comes from a website offereing autocad info in dotnet

the url to the project is:

http://through-the-interface.typepad.com/through_the_interface/2010/08/changing-the-layer-or-color-of-a-nested-entity-using-net-take-2.html

I'm presuming the code as shown compiles fine for the author so I dont' know
why it won't for me...maybe because i'm on express version?

thanks for any ideas

mark

Jeff Johnson

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Sep 28, 2010, 11:46:06 AM9/28/10

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"mp" <nos...@Thanks.com> wrote in message
news:i7svun$hcn$1...@news.eternal-september.org...

>I get the error in the subject line from the following line of code:
> SubentityId subEnt =
>
> new SubentityId(SubentityType.Null, System.IntPtr.Zero);
>
> the second argument of that method is defined as Int.

Well, IntPtr.Zero ultimately returns a pointer initialized to the zero
address, that is, the pointer value itself is 0. The cheap and cheesy way
would be to simply use 0 in the function call. However, a slightly more
elegant way would be use IntPtr's ToInt32() method:

= new SubentityId(SubentityType.Null, System.IntPtr.Zero.ToInt32());

None of this explains why the code was expected to work as-is. Perhaps the
method signature was changed and the text on the Web page is newer or older
than the change. Or it could be a typo.

Arne Vajhøj

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Sep 28, 2010, 2:56:52 PM9/28/10

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Either that method did take an IntPtr when it was compiled
or did never did compile.

Note that there are no quality control on blog posts.

Arne

mp

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Sep 29, 2010, 1:40:57 AM9/29/10

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"Arne Vajhøj" <ar...@vajhoej.dk> wrote in message
news:4ca23a63$0$50455$1472...@news.sunsite.dk...

true enough but as far as I can tell that guy is well thought of in the
autocad community, so I assume it's me doing something wrong.
Thanks
mark

mp

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Sep 29, 2010, 1:45:14 AM9/29/10

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"Jeff Johnson" <i....@enough.spam> wrote in message
news:i7t2k5$hq8$1...@news.eternal-september.org...

> "mp" <nos...@Thanks.com> wrote in message
> news:i7svun$hcn$1...@news.eternal-september.org...
>
>>I get the error in the subject line from the following line of code:
>> SubentityId subEnt =
>>
>> new SubentityId(SubentityType.Null, System.IntPtr.Zero);
>>
>> the second argument of that method is defined as Int.
>
> Well, IntPtr.Zero ultimately returns a pointer initialized to the zero
> address, that is, the pointer value itself is 0. The cheap and cheesy way
> would be to simply use 0 in the function call.

i thought of that and said....naahhh no one would do it that way....:-)

However, a slightly more
> elegant way would be use IntPtr's ToInt32() method:
>
> = new SubentityId(SubentityType.Null, System.IntPtr.Zero.ToInt32());
>

sheesh, why didnt I think to try putting a dot after the zero
object?....still not used to these cascading series of objects
i tried casting it to an int but not sure how that should look in c#

> None of this explains why the code was expected to work as-is. Perhaps the
> method signature was changed and the text on the Web page is newer or
> older than the change. Or it could be a typo.

Thanks for the solution
Mark