List DefaultItems (windows).

internal/win/user32.go

@@ -52,6 +52,8 @@ const (
 	WM_USER        = 0x0400
 	EM_SETSEL      = 0x00b1
 	LB_ADDSTRING   = 0x0180
+	LB_SETSEL      = 0x0185
+	LB_SETCURSEL   = 0x0186
 	LB_GETCURSEL   = 0x0188
 	LB_GETSELCOUNT = 0x0190
 	LB_GETSELITEMS = 0x0191

list.go

@@ -52,7 +52,7 @@ const (
 	radioListKind
 )
 
-// DefaultItems returns an Option to set the items to initially select (macOS only).
+// DefaultItems returns an Option to set the items to initially select (Windows and macOS only).
 func DefaultItems(items ...string) Option {
 	return funcOption(func(o *options) { o.defaultItems = items })
 }

list_windows.go

@@ -107,8 +107,17 @@ func (dlg *listDialog) setup(text string, opts options) ([]string, error) {
 			12, 206, 75, 24, dlg.wnd, win.IDNO, instance, nil)
 	}
 
-	for _, item := range dlg.items {
+	for i, item := range dlg.items {
 		win.SendMessagePointer(dlg.listCtl, win.LB_ADDSTRING, 0, unsafe.Pointer(strptr(item)))
+		for _, def := range opts.defaultItems {
+			if def == item {
+				if dlg.multiple {
+					win.SendMessage(dlg.listCtl, win.LB_SETSEL, 1, uintptr(i))
+				} else {
+					win.SendMessage(dlg.listCtl, win.LB_SETCURSEL, uintptr(i), 0)
+				}
+			}
+		}
 	}
 
 	dlg.layout(getDPI(dlg.wnd))