Autolayout（VFL）自动适配

  1 #import "ViewController.h"
  2 
  3 @interface ViewController ()
  4 
  5 @end
  6 
  7 @implementation ViewController
  8 
  9 - (void)viewDidLoad {
 10     [super viewDidLoad];
 11     
 12     [self fun5];
 13     
 14 }
 15 
 16 -(void)fun1{
 17     //注意使用VFL，不用设置视图的frame
 18     UIView *view = [[UIView alloc] init];
 19     view.backgroundColor = [UIColor brownColor];
 20     [self.view addSubview:view];
 21     
 22     view.translatesAutoresizingMaskIntoConstraints = NO;//注意，要想使约束条件起作用，必须将此属性设置为no
 23     
 24     /*
 25      VFL相关的标识符
 26      H:代表水平方向
 27      V:代表垂直方向
 28      |代表父视图
 29      - 代表距离 例（H:|-20-）表示距离父视图左侧20像素
 30      []代表子视图相关属性
 31      */
 32     
 33     //对子视图View进行约束设置，format表示要设置的约束语句，在本句中意思为：view距离父视图左侧30像素，距离父视图右侧20像素（如果没设置具体的数字，且写了-）
 34     //options代表对其方式，默认写0就行
 35     //metrics 这里是一个字典，当在format中使用了动态数据比如上现这句:@"H:|-[button(==width)]-|",表示这个button的宽度为width,那么这个参数去哪里找呢？就是在这个字典里面找到key对就的值，如果没有找到这个值，app会crash
 36     //views 代表约束条件中所涉及的所有视图（父视图除外）
 37     NSArray *arr = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|-30-[view]-|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(view)];
 38     
 39     NSArray *arr1 = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|-20-[view]-|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(view)];
 40     
 41     [self.view addConstraints:arr];
 42     [self.view addConstraints:arr1];
 43 
 44 }
 45 
 46 -(void)fun2{
 47     UIView *view = [[UIView alloc] init];
 48     view.backgroundColor = [UIColor grayColor];
 49     [self.view addSubview:view];
 50     
 51     view.translatesAutoresizingMaskIntoConstraints =  NO;
 52     //[view(>=200)]  表示给view设置尺寸，此时小括号里的关系运算符只能是 == <= >=，注意，改尺寸的值不要与约束冲突，==：约束可以不写，简写成H:[view(==200)]    >=：当左右距离只设置了一个或者都未设置，视图的尺寸为最小值，如果两个都设置时，view 的尺寸为屏幕宽度减去左右距离，此时要保证减后的值>=尺寸最小值
 53     
 54     NSArray *arr = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|-[view(>=200)]" options:0 metrics:nil views:NSDictionaryOfVariableBindings(view)];
 55     
 56      NSArray *arr1 = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|-20-[view(==100)]" options:0 metrics:nil views:NSDictionaryOfVariableBindings(view)];
 57     [self.view addConstraints:arr1];
 58     [self.view addConstraints:arr];
 59     
 60 }
 61 
 62 -(void)fun3{
 63     UIView *view = [[UIView alloc] init];
 64     view.backgroundColor = [UIColor grayColor];
 65     [self.view addSubview:view];
 66     
 67     view.translatesAutoresizingMaskIntoConstraints =  NO;
 68     
 69     CGFloat width = 200;
 70     
 71     //当我们在设置约束条件时，距离父视图上下左右的像素值以及view的尺寸不是固定的数字(用某个字符串代替)，这时我们需要给metrics设置一个字典，该字典的key必须是约束语句中使用的字符串，对应的value可以自行设置
 72     NSArray *arr = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|-left-[view(==width)]" options:0 metrics:@{@"width":[NSNumber numberWithFloat:width],@"left":@30} views:NSDictionaryOfVariableBindings(view)];
 73     
 74     NSArray *arr1 = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|-20-[view(==100)]" options:0 metrics:nil views:NSDictionaryOfVariableBindings(view)];
 75     [self.view addConstraints:arr1];
 76     [self.view addConstraints:arr];
 77     
 78 }
 79 
 80 -(void)fun4{
 81     UIView *view = [[UIView alloc] init];
 82     view.backgroundColor = [UIColor grayColor];
 83     [self.view addSubview:view];
 84     
 85     view.translatesAutoresizingMaskIntoConstraints =  NO;
 86     
 87     CGFloat width = 200;
 88     
 89     //当我们在设置约束条件时，距离父视图上下左右的像素值以及view的尺寸不是固定的数字(用某个字符串代替)，这时我们需要给metrics设置一个字典，该字典的key必须是约束语句中使用的字符串，对应的value可以自行设置
 90     NSArray *arr = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|-left-[view(==width)]" options:0 metrics:@{@"width":[NSNumber numberWithFloat:width],@"left":@30} views:NSDictionaryOfVariableBindings(view)];
 91     
 92     NSArray *arr1 = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|-20-[view(==100)]" options:0 metrics:nil views:NSDictionaryOfVariableBindings(view)];
 93     [self.view addConstraints:arr1];
 94     [self.view addConstraints:arr];
 95     
 96     
 97     UIView *view1 = [[UIView alloc] init];
 98     view1.backgroundColor = [UIColor purpleColor];
 99     [self.view addSubview:view1];
100     
101     view1.translatesAutoresizingMaskIntoConstraints = NO;
102     
103     //[view1(view)] 代表view1和view某个方向尺寸相同
104     NSArray *arr2 = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|-[view1(view)]-|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(view1,view)];
105     
106     //V:[view]-[view1]-20-|：子视图view1垂直方向距离平级子视图view 8像素（默认）
107     NSArray *arr3 = [NSLayoutConstraint constraintsWithVisualFormat:@"V:[view]-[view1]-20-|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(view,view1)];
108     [self.view addConstraints:arr2];
109     [self.view addConstraints:arr3];
110     
111     
112 }
113 
114 //用VFL实现label自适应
115 -(void)fun5{
116     UILabel *label = [[UILabel alloc] init];
117     label.backgroundColor = [UIColor grayColor];
118     label.numberOfLines = 0;
119     label.lineBreakMode = NSLineBreakByCharWrapping;
120     label.text = @"hiwehfdiuwehdiowqhdoiwehjdoiuwehdiouwhediuwheioudhewiuodhwehoihiuhiuhiuhiluhiuhiuhiuhihuhuuhhuh";
121     [self.view addSubview:label];
122     label.translatesAutoresizingMaskIntoConstraints = NO;
123     
124     NSArray *arr = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|-[label]-|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(label)];
125     
126     NSArray *arr1 = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|-20-[label]" options:0 metrics:nil views:NSDictionaryOfVariableBindings(label)];
127     
128     [self.view addConstraints:arr];
129     [self.view addConstraints:arr1];
130 }
131 
132 - (void)didReceiveMemoryWarning {
133     [super didReceiveMemoryWarning];
134     // Dispose of any resources that can be recreated.
135 }
136 
137 @end