当在托管类中调用非托管函数时,C/C++LI System.AccessViolationException
作者：互联网
我在C中有一个本机回调函数,我们可以这样说：
void ::CallbackFunction(void)
{
// Do nothing
}
现在,我还有另一个本机功能：
void ::SomeNativeFunction(void)
{
m_callback = std::tr1::bind(&::CallbackFunction, m_Tcy); // save in m_callback | m_Tcy is the class where CallbackFunction exists
m_Tcy->SomeManagedFunction(m_callback);
}
好了,现在我调用了托管函数,并为该函数提供了本机c函数.
让我们看一下托管代码：
// This won't work
// typedef std::tr1::function<void __stdcall ()>* callback_function;
typedef std::tr1::function<void()>* callback_function;
callback_function m_nativCallback;
void ::SomeManagedFunction(callback_function callback)
{
m_nativCallback = callback;
// Does some stuff that triggers SomeManagedCallback
}
void ::SomeManagedCallback(IAsyncResult^ ar)
{
(*m_nativCallback)();
}
现在,如果我对此进行调试,则会在.dll中收到类型为System.AccessViolationException的未处理异常.其他信息：试图读取或写入受保护的内存.这表明其他内存已损坏.错误信息.
调用约定有问题吗？
谢谢
解决方法:
本机部分设置错误：
void ::SomeNativeFunction(void)
{
m_callback = std::tr1::bind(&::CallbackFunction, m_Tcy); // save in m_callback | m_Tcy is the class where CallbackFunction exists
//this won't work
m_Tcy->SomeManagedFunction(m_callback);
}
这为我工作：
void ::SomeNativeFunction(void)
{
m_callback = std::tr1::bind(&::CallbackFunction, m_Tcy); // save in m_callback | m_Tcy is the class where CallbackFunction exists
//this works, even tho the debugger dies on me when I try to debug this
m_Tcy->SomeManagedFunction(&m_callback);
}
回调的东西可以用,但是在本地主目录中仍然会出现错误：
First-chance exception at 0x00007ffb2b59dd60 in *.exe: 0xC0000005: Access violation at location 0x00007ffb2b59dd60.
Unhandled exception at 0x00007ffb2b59dd60 in *.exe: 0xC000041D: Exception during a user callback.
另外,调试回调(在C/C++LI包装器中)时,Visual Studio 2010崩溃.如果我等待足够长的时间,它将引发以下异常：
Access violation reading location 0xfffffffffffffff8.