func RegisterClass(className string, wndproc uintptr) {
instance := GetAppInstance()
icon := w32.LoadIcon(instance, w32.MakeIntResource(w32.IDI_APPLICATION))
var wc w32.WNDCLASSEX
wc.Size = uint(unsafe.Sizeof(wc))
wc.Style = w32.CS_HREDRAW | w32.CS_VREDRAW
wc.WndProc = wndproc
wc.Instance = instance
wc.Background = w32.COLOR_BTNFACE + 1
wc.Icon = icon
wc.Cursor = w32.LoadCursor(0, w32.MakeIntResource(w32.IDC_ARROW))
wc.ClassName = syscall.StringToUTF16Ptr(className)
wc.MenuName = nil
wc.IconSm = icon
if ret := w32.RegisterClassEx(&wc); ret == 0 {
panic(syscall.GetLastError())
}
}
