func (b *Button) WndProc(msg uint32, wParam, lParam uintptr) uintptr {
	switch msg {
	case win.WM_COMMAND:
		switch win.HIWORD(uint32(wParam)) {
		case win.BN_CLICKED:
			if b.OnClicked != nil && lParam == uintptr(b.hwnd) {
				b.OnClicked()
			}
		case win.BN_DBLCLK:
			if b.OnDoubleClicked != nil && lParam == uintptr(b.hwnd) {
				b.OnDoubleClicked()
			}
		}
	}
	return b.AsWindowBase().WndProc(msg, wParam, lParam)
}
WndProc Button window WndProc.
package wingui
import (
	"github.com/lxn/win"
	"github.com/whtiehack/wingui/winapi"
	"log"
	"syscall"
	"unsafe"
)
type Button struct {
	WindowBase
	OnClicked       func()
	OnDoubleClicked func()
}