try this:
public void transferGameBase(List<string> infoBase)
{
int count = 0;
foreach(string _base in infoBase)
{
string[] _splitter = infoBase[count].ToString().Split(';');
drawBase(Convert.ToInt16(_splitter[0]), Convert.ToInt16(_splitter[1]), Convert.ToInt16(_splitter[2])); //[0] = x , [1] = y, [2] = size
count++;
}
this.Invalidate();
}
Basically, windows only redraws the form when it actually needs to, so when you manually draw something on top of it, you need to tell the form to redraw itself.