UIbaritem 添加到导航栏上增加边距

// 初始化按钮
    UIButton *settingBtn = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 50, 40)];
    
[settingBtn setTitle:title forState:UIControlStateNormal];
        [settingBtn setTitleColor:[UIColor colorWithHexString:color] forState:UIControlStateNormal];
        UIBarButtonItem *rightBar = [[UIBarButtonItem alloc]initWithCustomView:settingBtn];
        UIBarButtonItem *negativeSpacer = [[UIBarButtonItem alloc]
                                           initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace
                                           target:nil action:nil];
        negativeSpacer.width = -20;
        self.navigationItem.rightBarButtonItems = [NSArray arrayWithObjects:negativeSpacer,rightBar,nil];
        self.navigationItem.leftBarButtonItems = [NSArray arrayWithObjects:rightBarnegativeSpacer,nil];