【代码笔记】等待动画

#import <UIKit/UIKit.h>

@interface RootViewController : UIViewController
{
    NSTimer *timerWait;
    int j;
}
@end

#import "RootViewController.h"

@interface RootViewController ()

@end

@implementation RootViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    
    //初始化背景图
    [self initBackGroundView];
    
  
}
#pragma -mark -functions
//初始化背景图
-(void)initBackGroundView
{
    UIImageView *waitView = [[UIImageView alloc] initWithFrame:CGRectMake(50, 200, 130, 160)];
    waitView.tag = 103;
    [waitView setImage:[UIImage imageNamed:@"wait1.png"]];
    [self.view addSubview:waitView];
    
    timerWait = [NSTimer scheduledTimerWithTimeInterval:0.5 target:self selector:@selector(wait) userInfo:nil repeats:YES];
}
//等待函数
- (void)wait
{
    UIImageView *imageView = (UIImageView *)[self.view viewWithTag:103];
    if (j%4 == 0) {
        [imageView setImage:[UIImage imageNamed:@"wait1.png"]];
    }else if(j%11 == 0){
        [imageView setImage:[UIImage imageNamed:@"wait4.png"]];
    }else if(j%17 == 0){
        imageView.frame = CGRectMake(-10, 215, 170, 145);
        [imageView setImage:[UIImage imageNamed:@"wait3.png"]];
    }else{
        [imageView setImage:[UIImage imageNamed:@"wait2.png"]];
    }
    j++;
}

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