Autolayout（VFL）自動適配

  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，不用設置視圖的frame
 18     UIView *view = [[UIView alloc] init];
 19     view.backgroundColor = [UIColor brownColor];
 20     [self.view addSubview:view];
 21     
 22     view.translatesAutoresizingMaskIntoConstraints = NO;//注意，要想使約束條件起做用，必須將此屬性設置爲no
 23     
 24     /*
 25      VFL相關的標識符
 26      H:表明水平方向
 27      V:表明垂直方向
 28      |表明父視圖
 29      - 表明距離 例（H:|-20-）表示距離父視圖左側20像素
 30      []表明子視圖相關屬性
 31      */
 32     
 33     //對子視圖View進行約束設置，format表示要設置的約束語句，在本句中意思爲：view距離父視圖左側30像素，距離父視圖右側20像素（若是沒設置具體的數字，且寫了-）
 34     //options表明對其方式，默認寫0就行
 35     //metrics 這裏是一個字典，當在format中使用了動態數據好比上現這句:@"H:|-[button(==width)]-|",表示這個button的寬度爲width,那麼這個參數去哪裏找呢？就是在這個字典裏面找到key對就的值，若是沒有找到這個值，app會crash
 36     //views 表明約束條件中所涉及的全部視圖（父視圖除外）
 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)]  表示給view設置尺寸，此時小括號裏的關係運算符只能是 == <= >=，注意，改尺寸的值不要與約束衝突，==：約束能夠不寫，簡寫成H:[view(==200)]    >=：當左右距離只設置了一個或者都未設置，視圖的尺寸爲最小值，若是兩個都設置時，view 的尺寸爲屏幕寬度減去左右距離，此時要保證減後的值>=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     //當咱們在設置約束條件時，距離父視圖上下左右的像素值以及view的尺寸不是固定的數字(用某個字符串代替)，這時咱們須要給metrics設置一個字典，該字典的key必須是約束語句中使用的字符串，對應的value能夠自行設置
 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     //當咱們在設置約束條件時，距離父視圖上下左右的像素值以及view的尺寸不是固定的數字(用某個字符串代替)，這時咱們須要給metrics設置一個字典，該字典的key必須是約束語句中使用的字符串，對應的value能夠自行設置
 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)] 表明view1和view某個方向尺寸相同
104     NSArray *arr2 = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|-[view1(view)]-|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(view1,view)];
105     
106     //V:[view]-[view1]-20-|：子視圖view1垂直方向距離平級子視圖view 8像素（默認）
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實現label自適應
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