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Sorry, my fault, thanks for correcting me.
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Hey!
LongHC wrote: int payRate = MyNumberObject as int;
you can't use 'as' operator with value type classes :/ only reference type..
life is study!!!
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Hi,
AFAIK this is not possible.
You can implement implicit casting from some value type such as int to your type,
but not the other way around.
But you can provide a method to do the conversion, someting similar to
ToString() which exists for all objects, and ToInt32() which exists for
some classes (e.g. IntPtr).
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yes you can, try this:
public class MyClass
{
private int m_width;
public int Width
{
get { return m_width; }
set { m_width = value; }
}
public static implicit operator int (MyClass source)
{
int output = source == null ? 0 : source.Width;
return output;
}
public void Test()
{
int value = this;
Console.WriteLine(value);
}
}
 a peruvian programmer
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You are right of course, dont know what I was thinking here.
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i tend to err on the side of caution and use:
public static explicit operator int(MyClass source)
Russ
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Is there a standard .NET object that abstracts version information (at minimum, major, minor, edit and build numbers)?
/ravi
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You could use System.Diagnostics.FileVersionInfo, it gives you all the information your looking for.
Tarakeshwar Reddy
MCP, CCIE Q(R&S)
There are two kinds of people, those who do the work and those who take the credit. Try to be in the first group; there is less competition there. - Indira Gandhi
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Thanks! I knew there had to be something!
/ravi
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Even better - many thanks!
Which begs the question: why didn't it show up in my Google and MSDN search? 
/ravi
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Hello,
i pinvoke a function from an com api. The function needs two parameters, an com interface and one out parameter. The prototype from the function is
BOOL WINAPI theFunc(theObject* pObject, LPTSTR szName);
My Call
<br />
[System.Runtime.InteropServices.DllImport("mydll.dll")]<br />
static extern unsafe bool theFunc([MarshalAs(UnmanagedType.Interface)] theItem item, StringBuilder buffer);<br />
<br />
StringBuilder buffer = new StringBuilder(1024);<br />
try<br />
{<br />
bRet = teFunc(_o, buffer);<br />
}...<br />
In a normal Windows Application there is no error. The error occured only when i use the code in a c# Windows service. The exception is that the memory might be damaged... AccessViolationException
Any ideas?
-- modified at 14:54 Monday 16th April, 2007
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realmontanakid wrote: Any ideas?
How is native code going to be able to use a StringBuilder object? 
led mike
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Mike, this is standard procedure when passing in strings into functions that are expected to modify the string.
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Yes forgot that, had to go look it up again!
However if the native code will write to it the signature should include a bufferSize argument which is the preallocated StringBuffer.Capacity, yes?
led mike
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Is theItem being marshalled right? From the stuff you posted, I don't see anything that appears to be wrong.
*edit* are you sure you need StringBuilder? I don't think it will hurt, however, you should only use StringBuilder if the native method will be modifying/creating the string.
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I can do it with a StringBuilder or like this,
<br />
byte[] buffer = new byte[512];<br />
<br />
unsafe<br />
{<br />
fixed (byte* pBuffer = buffer)<br />
{<br />
ret = theFunc(_o, pBuffer);<br />
}<br />
}<br />
The second Parameter is an out param, it gives me a path to a file. If i do it with a StringBuilder or with a pointer to a buffer, it is the same result. In a Windows Forms Application, the buffer is NOT empty, in a Windows Service the buffer IS empty.. I try it on different machines and with different user accounts (Local System, User etc.). In a service it won't work.The com interface is marshalled correct.
Attempted to read or write protected memory. This is often an indication that other memory is corrupt."
-- modified at 17:29 Monday 16th April, 2007
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Hi,
StringBuilder is the right way to go when the function wants to return a string
value; it would be better to have a buffer size too in the argument list
(it would then be set to StringBuilder.Capacity), but if the function does not
take such an input, you should provide a sufficiently large StringBuilder.
For a single file spec, I believe 512 is the Windows maximum.
When I must call a native function that does not take a buffer size, I provide
a StringBuilder[1024].
I am afraid it is the other, the first, argument, that is causing your problems.
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Hi,
no the first argument is not the problem. I'm testing with a StringBuilder with a capacity from up to 10240 to ensure there is enough space.. but it don't work. That makes me crazy. So, i got a little Form Application with one button, on button click event i call the function and it works. When i do it in a ConsoleApp or a service it will not work. I don't think that my code is ugly.. i think here is something wrong with the hole frame. Is ther probably not enough or to much time between call and passing the function? Or could it be a Thread Problem?
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OK, lets suppose the marshalling is all right.
two ideas:
1.
What is special about the service ? what is the string you expect to get ?
does it exist when there is no user logged in ?
2.
a simple test may not call the gc and work fine, what if the gc starts acting up.
Are you passing some pointer somewhere that needs to be pinned so the gc
does not MOVE the object ?
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Another idea: check the STAThread/MTAThread situation for your different experiments.
It is an attribute that gets set automatically to your static Main() method.
BTW: Having the console app fail is good, it may allow you an easy debug with
Visual Studio...
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Hello everyone,
Is it possible to create enumerations dynamically which we can manipulate or even create/destroy at run-time?
Best regards.
.:: Something is Wrong ::.
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Yes it is possible. Look up Lightweight Code Generation.
That said, I'd question whether you truly need this; there's probably an easier way to accomplish your goal. What are you trying to do? I may be able to suggest a better alternative.
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Well, for example, I would like to create a generic vehicle class, in which I should use a vehicle type enumeration. But when someone needs to extend this types he/she should add some ne vehicle types to the enumeration.
.:: Something is Wrong ::.
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Use a list or a database rather than a dynamic enum.
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