call function in class

i want to change the "value" when run my app. but when i call RS232::PackageRecived in "RS232.cpp" i revived This Error :

Error 1 er开发者_如何学Cror C2352: 'RS232::PackageRecived' : illegal call of non-static member

////////////////////////////////////////////   RS232.cpp FILE

#include "RS232.h"
void RS232::PackageRecived()
{
value =123;
}
void TryCallPackageRecived()
{
RS232::PackageRecived(); // my compiler error is here
}
int RS232::Connect()
{
TryCallPackageRecived();
}
RS232::RS232(void)
{
}
RS232::~RS232(void)
{
}
////////////////////////////////////////////      RS232.h File
class RS232
{
public:
int value;
int Connect();
void PackageRecived();
RS232(void);
~RS232(void);
};
////////////////////////////////////////////    Main.cpp File
#include "RS232.h"
RS232 RS;
int main()
{
RS.Connect();
}

Your function, "TryCallPackageRecived()" is not a member of the RS232 class. It's trying to call a member function of RS232 that is not static. This is not allowed. When you want to call a non-static member function you need to call it on a particular object.

In this case, you could do:

RS.PackageRecived();

If you want to allow for multiple objects, you could modify your TryCallPackageRecived function to take a pointer to the RS232 object:

void TryCallPackageRecived(RS232 *ptr)
{
   if(ptr != 0)
      ptr->PackageRecived(); 
}

... more code ...

int RS232::Connect()
{
    TryCallPackageRecived(this);
}

That's because PackageRecived is not a static method and you can't call non-static methods without an object.

Either make it a static method (but it depends on your logic) or Call it directly since you are inside this class anyway.

void TryCallPackageRecived()
{
    PackageRecived(); // my compiler error is here
}

The obvious way to fix this would be to add TryCallPackageRecived() to your RS232 class:

////////////////////////////////////////////      RS232.h File
class RS232
{
public:
    int value;
    int Connect();
    void PackageRecived();
    void TryCallPackageRecived();
    RS232();
    ~RS232();
};

////////////////////////////////////////////   RS232.cpp 

// [...]    
void RS232::TryCallPackageRecived()
{
    PackageRecived();
}
// [...]