IOS笔记UI--首次启动介绍和LaunchDemo

申明：此为本人学习笔记，若有纰漏错误之处的可留言共同探讨

制作首次启动介绍app和Launch的效果，主要是通过在appDelegate里判断是不是第一次登陆该app，如果是，就将根视图赋给首次启动的那个VC（ViewController），如果不是就将根视图赋给launchVC。

/*

首次启动介绍和Launch思路

1.在appDelegate里，通过NSUserDefaults判断是不是第一次启动，如果是，把根视图给first；反之则把根视图赋给launch

2.在first首次启动介绍app这个VC里面呢。创建一个scrollVIew。需要几个介绍页面就创建几个UIImageView，然后在最后一个UIimageView加上手势，点击跳转到主视图

3.在launchVC里，使用performSelector这个方法，延时需要的时间长度，然后跳回主视图即可

*/

代码部分：

appDelegate判断部分

 if (![[NSUserDefaults standardUserDefaults]boolForKey:@"first"]) {
        // the first
        [[NSUserDefaults standardUserDefaults]setBool:YES forKey:@"first"];
        self.window.rootViewController = [[FLViewController alloc]init];
    } else {
        // not first
        self.window.rootViewController = [[LaunchViewController alloc]init];
    }

firstVC部分

#define MY_SCREEN_WIDTH self.view.bounds.size.width
#define MY_SCREEN_HEIGHT self.view.bounds.size.height
#define SCROLLVIEW_PAGE_NUMBER 4
#define ARC4RANDOM [UIColor colorWithRed:arc4random()%256/255. green:arc4random()%256/255. blue:arc4random()%256/255. alpha:1]

@interface FLViewController ()

@end

@implementation FLViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // ScrollView
    UIScrollView *scrollView = [[UIScrollView alloc]initWithFrame:self.view.frame];
    scrollView.contentSize = CGSizeMake(MY_SCREEN_WIDTH*SCROLLVIEW_PAGE_NUMBER,MY_SCREEN_WIDTH);
    [self.view addSubview:scrollView];
    scrollView.pagingEnabled = YES;
    scrollView.contentOffset =CGPointMake(0, 0);
    scrollView.showsHorizontalScrollIndicator =NO;
    scrollView.delegate = self;
    scrollView.bounces = NO;
    
    UIImageView *imageView;
    for (int i = 0 ; i

launchVC部分

#import "LaunchViewController.h"
#import "ViewController.h"
@interface LaunchViewController ()

@end

@implementation LaunchViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    UIImageView *imageView = [[UIImageView alloc]initWithFrame:self.view.frame];
    [self.view addSubview:imageView];
    UIImage *image = [UIImage imageNamed:@"myPic.jpg"];
    imageView.image = image;
    [self performSelector:@selector(gotoMain) withObject:self afterDelay:1.5];
}

#pragma mark - 
-(void)gotoMain {
    ViewController *mainVC = [[ViewController alloc]init];
    [self presentViewController:mainVC animated:NO completion:nil];
}

附上本人完整Demo：http://download.csdn.net/detail/csdn_hhg/9207599