gdi+ image resizing

[felix1432]

hi,

i have spent a couple of fruitless hours on this, maybe someone can help...

My main aim is to create screenshot of my screen, re-size it & save it to a file.


Dumping a screenshot into HBITMAP & saving that to disk works fine, however, changing the resolution wont work.

I can change the resolution of a image using the DrawImage() method of a Graphics object, but i can only Draw in an Image* object...not in a HBITMAP.

I fail at creating an empty Image* object.



HDC tmp= GetDC(0);
Graphics grr(tmp);
Image mim;//error
grr.DrawImage(&mim, 100, 100;
mim.Save(L"C:\\asdfasdf.jpg",0,0);


this code should take a screenshot, select ti into a Graphics object, and draw it into the image "mim" with an resolution of 100x100, but fails already at creating an empty image.


so how can i create an empty image?

[Lucassergei]

Because mim does not contain anything! That means your tmp fails to get a snapshot, which also means your provided snippet is incorrect. Supply us a more correct sample that actually works. And instead of creating an empty image then draw the scaled picture on it, I suggest you scale the taken snapshot into a placeholder of any size you want.

[ovidiucucu]

Image mim;//error

Gdiplus::Image class has not a default (with no parameters) constructor.