C++/CLI DateTime method argument

  • Thread starter Thread starter soren.enemaerke
  • Start date Start date
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soren.enemaerke

Hi everybody.

I'm writing a .NET wrapper class for a native C++ library and decided
to do it in C++/CLI. One of the problems I ran in to is the following.

In C++ I have the following

public ref class MyClass
{
....
bool DoIt(DateTime^% date);
bool DoIt2([OutAttribute] DateTime^% date)
}

which I think should translate into a method calls with c# syntax:

bool DoIt(ref DateTime date);
bool DoIt2(out DateTime date);

So I was a bit puzzled when the following showed up:

bool DoIt(ref ValueType date);

Where is my type safety? What am I doing wrong? Am I trying to do
something (returning value types from c++/cli via ref and out) that is
just not possible?

bool DoIt(ref ValueType date);
 
Hi everybody.

I'm writing a .NET wrapper class for a native C++ library and decided
to do it in C++/CLI. One of the problems I ran in to is the following.

In C++ I have the following

public ref class MyClass
{
...
bool DoIt(DateTime^% date);
bool DoIt2([OutAttribute] DateTime^% date)
}

which I think should translate into a method calls with c# syntax:

bool DoIt(ref DateTime date);
bool DoIt2(out DateTime date);

So I was a bit puzzled when the following showed up:

bool DoIt(ref ValueType date);

Where is my type safety? What am I doing wrong? Am I trying to do
something (returning value types from c++/cli via ref and out) that is
just not possible?
Click to expand...

You're using tracking handles (^) with a value type, which is not needed or
desired.

Just "bool DoIt(DateTime% date);" will work properly.
 
Hi everybody.
Click to expand...
I'm writing a .NET wrapper class for a native C++ library and decided
to do it in C++/CLI. One of the problems I ran in to is the following.
Click to expand...
In C++ I have the following
Click to expand...
public ref class MyClass
{
...
bool DoIt(DateTime^% date);
bool DoIt2([OutAttribute] DateTime^% date)
}
Click to expand...
which I think should translate into a method calls with c# syntax:
Click to expand...
bool DoIt(ref DateTime date);
bool DoIt2(out DateTime date);
Click to expand...
So I was a bit puzzled when the following showed up:
Click to expand...
bool DoIt(ref ValueType date);
Click to expand...
Where is my type safety? What am I doing wrong? Am I trying to do
something (returning value types from c++/cli via ref and out) that is
just not possible?
Click to expand...

You're using tracking handles (^) with a value type, which is not needed or
desired.

Just "bool DoIt(DateTime% date);" will work properly.




bool DoIt(ref ValueType date);- Skjul tekst i anførselstegn -
Click to expand...

- Vis tekst i anførselstegn -- Skjul tekst i anførselstegn -

- Vis tekst i anførselstegn -
Click to expand...

Thanks Ben, worked like a charm.
 
DateTime is a value type, however the track handle ^ makes the parameter to
be boxed. C# does not understand the type of a boxed value type, but C++/CLI
does. So you have ref ValueType in C#, and DateTime^ in C++/CLI.
 
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