iOS: 学习笔记, 用代码驱动自动布局实例

iOS自动布局是设置iOS界面的利器.

本实例展示了如何使用自动布局语言设置水平布局, 垂直布局

1. 创建空白iOS项目

2. 添加一个控制器类, 修改YYAppDelegate.m文件

#import "YYAppDelegate.h"#import "YYViewController.h"@implementation YYAppDelegate- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];    // Override point for customization after application launch.    self.window.backgroundColor = [UIColor whiteColor];        self.window.rootViewController = [[YYViewController alloc] initWithNibName:nil bundle:nil];        [self.window makeKeyAndVisible];    return YES;}

3. 修改控制器类

////  YYViewController.m//  UIBasic060701_Button////  Created by yao_yu on 14-6-7.//  Copyright (c) 2014年 yao_yu. All rights reserved.//#import "YYViewController.h"@interface YYViewController ()@property(nonatomic, strong) UIView *viewMoveBlock;@end@implementation YYViewController- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil{    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];    if (self) {        // Custom initialization    }    return self;}- (void)viewDidLoad{    [super viewDidLoad];        self.viewMoveBlock = [[UIView alloc] init];    [self.viewMoveBlock setBackgroundColor:[UIColor blueColor]];    self.viewMoveBlock.frame = CGRectMake(100, 100, 20, 20);    [self.view addSubview: self.viewMoveBlock];        UIView *commandPane = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 160, 40)];    [self.view addSubview:commandPane];    const CGFloat BUTTONSIZE = 40;    UIButton *buttonLeft = [UIButton buttonWithType:UIButtonTypeRoundedRect];    [buttonLeft setTitle:@"左移" forState:UIControlStateNormal];    buttonLeft.frame = CGRectMake(0, 0, BUTTONSIZE, BUTTONSIZE);    [commandPane addSubview: buttonLeft];    [buttonLeft addTarget:self action:@selector(moveLeft) forControlEvents:UIControlEventTouchUpInside];        UIButton *buttonRight = [UIButton buttonWithType:UIButtonTypeRoundedRect];    [buttonRight setTitle:@"右移" forState:UIControlStateNormal];    buttonRight.frame = CGRectMake(BUTTONSIZE, 0, BUTTONSIZE, BUTTONSIZE);    [commandPane addSubview: buttonRight];    [buttonRight addTarget:self action:@selector(moveRight) forControlEvents:UIControlEventTouchUpInside];        UIButton *buttonUp = [UIButton buttonWithType:UIButtonTypeRoundedRect];    [buttonUp setTitle:@"上移" forState:UIControlStateNormal];    buttonUp.frame = CGRectMake(BUTTONSIZE*2, 0, BUTTONSIZE, BUTTONSIZE);    [commandPane addSubview: buttonUp];    [buttonUp addTarget:self action:@selector(moveUp) forControlEvents:UIControlEventTouchUpInside];        UIButton *buttonDown = [UIButton buttonWithType:UIButtonTypeRoundedRect];    [buttonDown setTitle:@"下移" forState:UIControlStateNormal];    buttonDown.frame = CGRectMake(BUTTONSIZE*3, 0, BUTTONSIZE, BUTTONSIZE);    [commandPane addSubview: buttonDown];    [buttonDown addTarget:self action:@selector(moveDown) forControlEvents:UIControlEventTouchUpInside];        UIButton *buttonZoomOut = [UIButton buttonWithType:UIButtonTypeRoundedRect];    [buttonZoomOut setTitle:@"放大" forState:UIControlStateNormal];    buttonZoomOut.frame = CGRectMake(BUTTONSIZE*4, 0, BUTTONSIZE, BUTTONSIZE);    [commandPane addSubview: buttonZoomOut];    [buttonZoomOut addTarget:self action:@selector(zoomOut) forControlEvents:UIControlEventTouchUpInside];        UIButton *buttonZoomIn = [UIButton buttonWithType:UIButtonTypeRoundedRect];    [buttonZoomIn setTitle:@"缩小" forState:UIControlStateNormal];    buttonZoomIn.frame = CGRectMake(BUTTONSIZE*5, 0, BUTTONSIZE, BUTTONSIZE);    [commandPane addSubview: buttonZoomIn];    [buttonZoomIn addTarget:self action:@selector(zoomIn) forControlEvents:UIControlEventTouchUpInside];        [commandPane setTranslatesAutoresizingMaskIntoConstraints:NO];    [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"[commandPane(260)]" options:0 metrics:0 views:NSDictionaryOfVariableBindings(commandPane)]];    [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-[commandPane(50)]" options:0 metrics:0 views:NSDictionaryOfVariableBindings(commandPane)]];    [self.view addConstraint:[NSLayoutConstraint constraintWithItem:commandPane attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeCenterX multiplier:1.0f constant:0.0f]];        NSDictionary *metrics = [NSDictionary dictionaryWithObjectsAndKeys:@40, @"SIZE", nil];    NSDictionary *contraitsView = NSDictionaryOfVariableBindings(buttonLeft, buttonRight, buttonUp, buttonDown, buttonZoomOut, buttonZoomIn);    for (NSString *buttonKey in contraitsView ) {        [contraitsView[buttonKey] setTranslatesAutoresizingMaskIntoConstraints:NO];        [commandPane addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:[NSString stringWithFormat:@"V:|[%@(SIZE)]", buttonKey] options:0 metrics:metrics views:contraitsView]];    }    [commandPane addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|[buttonLeft(SIZE)][buttonRight(SIZE)][buttonUp(SIZE)][buttonDown(SIZE)]-(>=0)-[buttonZoomOut(SIZE)][buttonZoomIn(SIZE)]|" options:0 metrics:metrics views: contraitsView]];}-(void)moveLeft{    [self moveX: -20 Y:0];}-(void)moveRight{    [self moveX: 20 Y:0];}-(void)moveUp{    [self moveX: 0 Y:-20];}-(void)moveDown{    [self moveX: 0 Y:20];}-(void)zoomOut{    CGRect rect = self.viewMoveBlock.frame;        rect.origin.x -= 20;    rect.origin.y -= 20;    rect.size.width += 40;    rect.size.height += 40;            [UIView beginAnimations:nil context:nil];    [UIView setAnimationDuration:1.0];        self.viewMoveBlock.frame = rect;        [UIView commitAnimations];}-(void)zoomIn{    CGRect rect = self.viewMoveBlock.frame;        rect.origin.x += 20;    rect.origin.y += 20;    rect.size.width -= 40;    rect.size.height -= 40;            [UIView beginAnimations:nil context:nil];    [UIView setAnimationDuration:1.0];        self.viewMoveBlock.frame = rect;        [UIView commitAnimations];}-(void)moveX: (int)x Y:(int)y{    CGPoint p = self.viewMoveBlock.center;        p.x += x;    p.y += y;        [UIView beginAnimations:nil context:nil];    [UIView setAnimationDuration:1.0];        self.viewMoveBlock.center = p;        [UIView commitAnimations];}- (void)didReceiveMemoryWarning{    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}/*#pragma mark - Navigation// In a storyboard-based application, you will often want to do a little preparation before navigation- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{    // Get the new view controller using [segue destinationViewController].    // Pass the selected object to the new view controller.}*/@end

4. 运行