(9/18)重学Standford_iOS7开发_动画、自动布局_课程笔记

时间:2023-03-09 01:15:13
(9/18)重学Standford_iOS7开发_动画、自动布局_课程笔记

最近开始实习,没多少时间更新了=_=

第九课:

  1、上节课demo:Dropit完整实现

    https://github.com/NSLogMeng/Stanford_iOS7_Study/commit/cfc24c2c4300185d972cf151872d313414a48d32

  2、Autolayout

    比较简单请参照课件截图https://github.com/NSLogMeng/Stanford_iOS7_Study/blob/master/Slides/Lecture%209%20Slides.pdf

    课程实现方法为在storyboard中可视化实现,本文再介绍两种方法:

    ①NSLayoutConstraint

+(instancetype)constraintWithItem:(id)view1
attribute:(NSLayoutAttribute)attr1
relatedBy:(NSLayoutRelation)
relation toItem:(id)view2
attribute:(NSLayoutAttribute)attr2
multiplier:(CGFloat)multiplier constant:(CGFloat)c;
//约束:item1.attribute =(>=,<=related) multiplier * item2.attribute + constant //使用UIView添加约束
- (void)addConstraint:(NSLayoutConstraint *)constraint

    ②Visual Format Language(VFL)

      官方文档很简单易懂

                  语法:

含义 语法 含义 语法
水平方向 H: 关系 >=,<=,==
垂直方向 V: 空间,间隙 -
Views [view] 优先级 @value
superView |    

      举例:

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    代码实现举例:

- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
UIButton *button1 = [[UIButton alloc] init];
button1.backgroundColor = [self randomColor];
[button1 setTitle:@"button1" forState:UIControlStateNormal];
button1.translatesAutoresizingMaskIntoConstraints = NO;//手动创建的代码使用VFL必须更改此属性
button1.layer.cornerRadius = 4.0f;
[self.view addSubview:button1]; [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-[button1]-|" options: metrics:nil views:NSDictionaryOfVariableBindings(button1)]];
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-20-[button1(width)]" options: metrics:@{@"width" : @} views:NSDictionaryOfVariableBindings(button1)]]; UIButton *button2 = [[UIButton alloc] init];
button2.backgroundColor = [self randomColor];
[button2 setTitle:@"button2" forState:UIControlStateNormal];
button2.translatesAutoresizingMaskIntoConstraints = NO;//手动创建的代码使用VFL必须更改此属性
button2.layer.cornerRadius = 4.0f;
[self.view addSubview:button2]; [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-[button2]-|" options: metrics:nil views:NSDictionaryOfVariableBindings(button2)]];
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:[button1]-44-[button2(30)]" options: metrics:nil views:NSDictionaryOfVariableBindings(button1,button2)]]; UITabBar *tabBar = [[UITabBar alloc] init];
tabBar.barTintColor = [UIColor colorWithRed:/255.0f green:/255.0f blue:/255.0f alpha:1.0f];
tabBar.translatesAutoresizingMaskIntoConstraints = NO;//手动创建的代码使用VFL必须更改此属性 UITabBarItem *item1 = [[UITabBarItem alloc] init];
[item1 setTitle:@"item1"]; UITabBarItem *item2 = [[UITabBarItem alloc] init];
[item2 setTitle:@"item2"]; UITabBarItem *item3 = [[UITabBarItem alloc] init];
[item3 setTitle:@"item3"]; tabBar.items = @[item1,item2,item3]; [self.view addSubview:tabBar];
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|[tabBar]|" options: metrics:nil views:NSDictionaryOfVariableBindings(tabBar)]];
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:[tabBar(45)]|" options: metrics:nil views:NSDictionaryOfVariableBindings(tabBar)]]; [button1 addTarget:self action:@selector(touchButton1) forControlEvents:UIControlEventTouchDown]; }

        注意:①代码创建的view要加 button1.translatesAutoresizingMaskIntoConstraints = NO;才能生效

            ②metrics存储VFL中可变量的值(字典),可以参考button1的约束

            ③views参数对应VFL中View的值(通过NSDictionaryOfVariableBindings(...)实现)

  3、作业

    还没做=_=,后面补。

课程视频地址:网易公开课:http://open.163.com/movie/2014/1/B/P/M9H7S9F1H_M9H80K2BP.html

       或者iTunes U搜索standford课程