C++/CLI DateTime method argument

[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);

 

[Ben Voigt [C++ MVP]]

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?

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

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

 

[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?

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 -

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

- Vis tekst i anførselstegn -

Thanks Ben, worked like a charm.

 

[Sheng Jiang[MVP]]

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.