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 ()<UIScrollViewDelegate>

@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<SCROLLVIEW_PAGE_NUMBER; i++) {
imageView = [[UIImageView alloc]initWithFrame:CGRectMake(i*375, 0, MY_SCREEN_WIDTH, MY_SCREEN_HEIGHT)];
imageView.backgroundColor = ARC4RANDOM;
[scrollView addSubview:imageView];
imageView.tag = 1+i;

}

[imageView setUserInteractionEnabled:YES];

UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(gotoMain:)];

[[self.view viewWithTag:SCROLLVIEW_PAGE_NUMBER] addGestureRecognizer:tap];

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

}

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