VFL語言的使用

 1 //
 2 //  ViewController.m
 3 //  D01-VFL語言使用(瞭解)
 4 //
 5 //  Created by apple on 15/8/8.
 6 //  Copyright (c) 2015年 apple. All rights reserved.
 7 //
 8 
 9 
10 /**
11  1.添加一個blueView和redView在控制器的View中
12  2.約束blueView的左邊,右邊,上邊,距離控制器View的距離都爲20;
13  3.約束blueView的高度爲固定50;
14  4.約束redView和blueView右對齊;
15  5.約束redView的頂部距離blueView的底部爲20的間距;
16  6.約束redView的寬度爲blueView寬度的一半;
17  */
18 #import "ViewController.h"
19 
20 @interface ViewController ()
21 
22 @end
23 
24 @implementation ViewController
25 
26 - (void)viewDidLoad {
27     [super viewDidLoad];
28     
29     UIView *blueView = [[UIView alloc] init];
30     blueView.backgroundColor = [UIColor blueColor];
31     [self.view addSubview:blueView];
32     
33     
34     UIView *redView = [[UIView alloc] init];
35     redView.backgroundColor = [UIColor redColor];
36     [self.view addSubview:redView];
37     
38     // 禁用Autoresizing功能
39     blueView.translatesAutoresizingMaskIntoConstraints = NO;
40     redView.translatesAutoresizingMaskIntoConstraints = NO;
41     /**
42      
43      NSLayoutFormatAlignAllLeft = (1 << NSLayoutAttributeLeft),
44      NSLayoutFormatAlignAllRight = (1 << NSLayoutAttributeRight),
45      NSLayoutFormatAlignAllTop = (1 << NSLayoutAttributeTop),
46      NSLayoutFormatAlignAllBottom = (1 << NSLayoutAttributeBottom),
47      NSLayoutFormatAlignAllLeading = (1 << NSLayoutAttributeLeading),
48      NSLayoutFormatAlignAllTrailing = (1 << NSLayoutAttributeTrailing),
49      NSLayoutFormatAlignAllCenterX = (1 << NSLayoutAttributeCenterX),
50      NSLayoutFormatAlignAllCenterY = (1 << NSLayoutAttributeCenterY),
51      NSLayoutFormatAlignAllBaseline = (1 << NSLayoutAttributeBaseline),
52      NSLayoutFormatAlignAllLastBaseline = NSLayoutFormatAlignAllBaseline,
53      NSLayoutFormatAlignAllFirstBaseline NS_ENUM_AVAILABLE_IOS(8_0) = (1 << NSLayoutAttributeFirstBaseline),
54      
55      NSLayoutFormatAlignmentMask = 0xFFFF,
56      */
57     
58     // 添加水平方向blueView的約束
59     NSArray *HBlueViewConstraint = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|-20-[blueView]-20-|" options:NSLayoutFormatAlignAllBottom metrics:nil views:@{@"blueView" : blueView}];
60     [self.view addConstraints:HBlueViewConstraint];
61     
62     // 添加垂直方向的約束
63     NSArray *VConstraint = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|-20-[blueView(50)]-20-[redView(==blueView)]" options:NSLayoutFormatAlignAllRight metrics:nil views:@{@"blueView" : blueView, @"redView" : redView}];
64     [self.view addConstraints:VConstraint];
65 
66 #warning mark - VFL不支持運算符
67     // 添加redView水平方法的約束
68     //    NSArray *HRedViewConstraint = [NSLayoutConstraint constraintsWithVisualFormat:@"H:[redView(==blueView)]" options:NSLayoutFormatAlignAllRight metrics:nil views:@{@"blueView" : blueView, @"redView" : redView}];
69     //    [self.view addConstraints:HRedViewConstraint];
70     
71     // 添加redView寬度等於blueView的寬度的一半
72     NSLayoutConstraint *redViewWidth = [NSLayoutConstraint constraintWithItem:redView attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:blueView attribute:NSLayoutAttributeWidth multiplier:0.5 constant:0];
73     [self.view addConstraint:redViewWidth];
74 }
75 
76 @end