如何转发在C ++ / CLI中声明一个委托? [英] How do I forward declare a delegate in C++/CLI?
问题描述
以下内容无效:
委托MyDelegate;
ref class MyDelegate;
delegate void MyDelegate;
以下内容用于声明:
public delegate void MyDelegate(Object ^ sender,MyArgs ^ args);
但使用它作为转发声明给我
错误C3756:'MyNameSpace :: MyDelegate':委托定义与现有符号冲突
这项工作适用于我;
stdafx.h:
public delegate void Handler(bool isit);
cli1.cpp:
#includestdafx.h
using namespace System;
命名空间MY {
命名空间命名空间
{
public ref class Objeks
{
public:Objeks(){}
public:event Handler ^ OnHandler;
public:void __clrcall Runner(bool checkit)
{
if(& Objeks :: OnHandler!= nullptr)
OnHandler(checkit);
}
};
}
}
我单独离开了默认的VS 2010 C ++ / CLI项目在大多数情况下,我希望如果你经历了前向声明的麻烦,则使用命名空间System;会去标题的还有:)
也许你不想使用事件?但是似乎只是结构。
我在考虑后添加了错误检查(错误编译C ++ / CLI使用Predicate与Array :: FindAll()进行委托调用)。
How?
The following did not work:
delegate MyDelegate;
ref class MyDelegate;
delegate void MyDelegate;
The following works for declaration:
public delegate void MyDelegate(Object ^sender, MyArgs ^args);
But using it as a forward declaration gives me
error C3756: 'MyNameSpace::MyDelegate': delegate definition conflicts with an existing symbol
This work's for me;
stdafx.h:
public delegate void Handler(bool isit);
cli1.cpp:
#include "stdafx.h"
using namespace System;
namespace MY {
namespace Namespace
{
public ref class Objeks
{
public: Objeks() {}
public: event Handler^ OnHandler;
public: void __clrcall Runner(bool checkit)
{
if(&Objeks::OnHandler != nullptr)
OnHandler(checkit);
}
};
}
}
I left the default VS 2010 C++/CLI project alone for the most part, I would expect that if your going through the trouble of forward declarations, the using namespace System; would go in the header's also :)
Maybe you did not want to use event? But it seems to simply the structure.
I added the error check after considering (Error Compiling C++/CLI Delegate call using Predicate with Array::FindAll()).
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