ios开发——为第二个demo加上欢迎界面

欢迎界面如下

用轮播图效果实现，共五张图片，滑到最后一张的时候点击“进入应用”按键，可以进入应用。

创建WelcomeViewController类，修改AppDelegate文件，设置初始登录界面为WelcomeViewController类创建的界面，代码如下

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    WelcomeViewController *view=[[WelcomeViewController alloc]init];
    self.window.rootViewController=view;
    [self.window makeKeyAndVisible];
    
    // Override point for customization after application launch.
    return YES;
}

WelcomeViewController文件中需要引用UIScrollViewDelegate协议，代码如下

#import "WelcomeViewController.h"
#import "AppDelegate.h"
@interface WelcomeViewController ()
@property (nonatomic,strong) UIScrollView *scrollView;
@property (nonatomic,strong) UIPageControl *pageControl;
@property (nonatomic,strong) NSMutableArray *imageArray;
@end

@implementation WelcomeViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor whiteColor];
    
    self.scrollView=[[UIScrollView alloc]initWithFrame:self.view.bounds];
    self.scrollView.delegate=self;
    self.scrollView.contentSize=CGSizeMake(self.view.bounds.size.width*5, self.view.bounds.size.height) ;
    self.scrollView.pagingEnabled=YES;
    self.scrollView.showsVerticalScrollIndicator=NO;
    self.scrollView.showsHorizontalScrollIndicator=NO;
    for(int i=0;i<5;i++){
        //        self.pageControl.hidden=NO; //hidden代码写在这里无效
        CGFloat x=i*self.view.bounds.size.width;
        UIImageView *scrollImgView=[[UIImageView alloc]initWithFrame:CGRectMake(x, 0, self.view.bounds.size.width, self.view.bounds.size.height)];
        NSString *imgName=[NSString stringWithFormat:@"bg_guide_6_%d",i+1];  //格式转换，获取图片名称
        scrollImgView.image=[UIImage imageNamed:imgName];
        [self.scrollView addSubview:scrollImgView];
        if(i==4){
            //            self.pageControl.hidden=YES;   //hidden代码写在这里无效
            UIButton *btn=[UIButton buttonWithType:UIButtonTypeRoundedRect];
            btn.backgroundColor=[UIColor clearColor];
            btn.frame=CGRectMake(80+self.view.bounds.size.width*4, self.view.bounds.size.height-200, self.view.bounds.size.width-160, 150);  //需要注意的是button距左边界的距离要加上self.view.bounds.size.width*4，即要加上前面四个页面
            [btn addTarget:self action:@selector(jumpToLogin) forControlEvents:UIControlEventTouchUpInside];
            [self.scrollView addSubview:btn];
        }
    }
    [self.view addSubview:self.scrollView];
       
    self.pageControl=[[UIPageControl alloc]initWithFrame:CGRectMake((self.view.bounds.size.width-100)/2, self.view.bounds.size.height-50, 100, 30)];
    self.pageControl.currentPage=0;
    self.pageControl.numberOfPages=4;
    self.pageControl.currentPageIndicatorTintColor=[UIColor lightGrayColor];
    self.pageControl.pageIndicatorTintColor=[UIColor grayColor];
    [self.view addSubview:self.pageControl];
    
}

-(void)scrollViewDidScroll:(UIScrollView *)scrollView{
    CGFloat offset=self.scrollView.contentOffset.x;
    int page=(offset+self.view.bounds.size.width/2)/self.view.bounds.size.width;
    self.pageControl.currentPage=page;
    if(page==4){  //控制最后一页不显示pagecontroller
        self.pageControl.hidden=YES;
    }else{
        self.pageControl.hidden=NO;
    }
}

- (void)jumpToLogin {
    AppDelegate *myAppDelegate = (AppDelegate *)[UIApplication sharedApplication].delegate;
    [myAppDelegate changeToLogin];  //调用跳转方法
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

因为想要最后一个页面不显示pagecontroller， 所以在scrollviewdidscroll代理方法中根据page值来确定pagecontroller的hidden属性。