iOS学习(UI)知识点整理
一、UINavigationBar 的介绍
1)概念:UINavigationBar 是用于定义导航栏按钮的一个类对象
2)在使用UINavigationBar之前必须先初始化导航栏 实例代码:
1 //初始化导航栏 2 FirstViewController *firstVC = [[FirstViewController alloc] init]; 3 UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:firstVC]; 4 self.window.rootViewController = nav; 5 6 //appearance一定要在初始化之前使用 7 //修改默认的UINavigationBar的导航条背景颜色, 8 [[UINavigationBar appearance] setBarTintColor:[UIColor yellowColor]]; 9 10 //修改默认的导航栏文字即图标颜色 11 [[UINavigationBar appearance] setTintColor:[UIColor blackColor]]; 12 13 //设置导航栏背景图片 14 [[UINavigationBar appearance] setBackgroundImage:[UIImage imageNamed:@"icon"] forBarMetrics:UIBarMetricsDefault];
3)setNavigationBarHidden 设置隐藏导航栏 例如:
1 [self.navigationController setNavigationBarHidden:YES];
4)title 设置导航栏标题 例如:
1 self.title = @“First View”; 2 //注意:在一处做此设置后,后面的视图控制器如未作设置也会使用此标题
5)titleView 用于设置导航栏中间的视图 例如:
1 UIView *navBarView = [[UIView alloc] init]; 2 navBarView.frame = CGRectMake(0, 0, 100, 30); 3 navBarView.backgroundColor = [UIColor clearColor]; 4 navBarView.layer.cornerRadius = 8.0f; 5 navBarView.clipsToBounds = YES; 6 7 UIButton *btn1 = [[UIButton alloc] init]; 8 btn1.frame = CGRectMake(0, 0, 50, 30); 9 btn1.backgroundColor = [UIColor blueColor]; 10 [btn1 setTitle:@"消息" forState:UIControlStateNormal]; 11 [btn1 addTarget:self action:@selector(btn1Tapped:) forControlEvents:UIControlEventTouchUpInside]; 12 btn1.tag = 1000; 13 [navBarView addSubview:btn1]; 14 15 UIButton *btn2 = [[UIButton alloc] init]; 16 btn2.frame = CGRectMake(50, 0, 50, 30); 17 btn2.backgroundColor = [UIColor blueColor]; 18 [btn2 setTitle:@"电话" forState:UIControlStateNormal]; 19 [btn2 addTarget:self action:@selector(btn1Tapped:) forControlEvents:UIControlEventTouchUpInside]; 20 btn2.tag = 1001; 21 [navBarView addSubview:btn2]; 22 23 //在导航栏中的中间位置加入我们自定义的view, 24 //程序会把我们设置的view自动居中 25 self.navigationItem.titleView = navBarView;
6)UIBarButtonItem 导航栏上的按钮元素 常用的系统自带的Bar有
/*
* UIBarButtonSystemItemDone 按钮样式为文字Done、
* UIBarButtonSystemItemAdd 按钮样式为图片的加号
*UIBarButtonSystemItemCamera 按钮样式是图片的照相机
*UIBarButtonSystemItemFixedSpace 是一个占位符 ,可以设置width
*UIBarButtonSystemItemFlexibleSpace 是一个占位符,固定宽度,导航栏上单独一个按钮
*/
例如:
1 //系统自带照相机按钮 2 UIBarButtonItem *button1 = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemCamera
target:self action:@selector(barButtonTapped:)]; 3 4 //占位符按钮 5 UIBarButtonItem *button2 = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace
target:self action:@selector(barButtonTapped:)];
7)rightBarButtonItem 设置导航栏右侧单个按钮 例如:
1 self.navigationItem.rightBarButtonItem = button1;
8)rightBarButtonItems 设置导航栏右侧多个按钮 例如:
1 self.navigationItem.rightBarButtonItems = @[button2, button1];
9)edgesForExtendedLayout 设置view的坐标都是从导航栏左下点开始计算 防止导航栏遮挡内容区域例如:
1 self.edgesForExtendedLayout = UIRectEdgeNone;
10)initWithTitle 使用文字作为导航栏按钮 例如:
1 UIBarButtonItem *barButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"返回" style:UIBarButtonItemStylePlain
target:self action:@selector(back)];
11)initWithImage 使用图片作为导航栏按钮 例如:
1 UIBarButtonItem *barButtonItem = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"st_logout"]
style:UIBarButtonItemStylePlain target:self action:@selector(back)]; 2 self.navigationItem.leftBarButtonItem = barButtonItem;
12)setToolbarHidden 设置导航栏显示与隐藏 例如:
1 [self.navigationController setToolbarHidden:NO];