iOS13获取App的keyWindow的方式

直接上代码吧：

- (UIWindow *)getKeyWindow {
    if([[[UIApplication sharedApplication] delegate] window]){
        return [[[UIApplication sharedApplication] delegate] window];
    }else {
        if (@available(iOS 13.0,*)) {
            NSArray *arr = [[[UIApplication sharedApplication] connectedScenes] allObjects];
            UIWindowScene *windowScene =  (UIWindowScene *)arr[0];
            UIWindow *mainWindow = [windowScene valueForKeyPath:@"delegate.window"];
            if(mainWindow){
                return mainWindow;
            }else{
                return [UIApplication sharedApplication].windows.lastObject;
            }
        }else {
            return [UIApplication sharedApplication].keyWindow;
        }
    }
}