C / C++ / MFC

int WINAPI PaintSpecialGraphics(HDC hDC);

int WINAPI PaintSpecialGraphics(HDC hDC)
{
    CDC dc;
    dc.Attach(hDC);
    // Do stuff with 'dc' here...
    dc.Detach();
}

CPaintDC dc(this);
PaintSpecialGraphics(dc);

Stephen Hewitt wrote:

I suspect you can't use MFC classes across DLL boundries. Here are some possible reasons:
- MFC's handle map implementation.
- Different heaps.
- Different compiler settings in EXE and DLL.

class CExample
{
public:
    int GetNum() { return g_Number; }
}

Zac Howland wrote:

First, using operations like CreateWindow in your constructor is dangerous since if CreateWindow fails, you have not completed your construction of the object. It is safer to initialize any variables and have a separate Create function to create your window.

Zac Howland wrote:

Doing this as part of the static memory allocation for your Dll can cause problems if the DLL fails to load properly. Basically, the same arguments for not calling CreateWindow inside your DllMain apply to calling it before it gets called as well.

Nader Elshehabi wrote:

char* MyText = new char;
cin>>MyText;
delete[] MyText;

void main()
{
	char* MyText = new char;
	cin>>MyText;
	delete MyText;
}

void main()
{
	char* MyText = new char[100];
	cin>>MyText;
	delete [] MyText;
}

Nader Elshehabi wrote:

Well, the first coder didn't work, while the second did.

Nader Elshehabi wrote:

Yet, that makes a buffer of N chars. That's not what I want. What if the user inputs n+1 chars.

char ch;
string input;
while ((ch = cin.getc()) != '\n')
{
   input += ch;
}

char* MyText = new char[5];
cin>>MyText;
MyText = new char[10];
delete[] MyText;

Regards

Nader Elshehabi wrote:

Is there a leak here??

Nader Elshehabi wrote:

Will the memory be freed?

Nader Elshehabi wrote:

Now , I called a second new without deleting the first one. Is there a leak here??

Nader Elshehabi wrote:

What if I didn't call a delete at all!! Once my program finishes and closes. Will the memory be freed?
Or will it be permanently locked until reboot?

Zac Howland wrote:

Are you coming from a Java/C# background by chance?

Extra Regards

getline(cin, input);

char buffer[100] = {0};
cin.getline(buffer, 99);