本文例項為大家分享了iOS實現圖片自動切換的具體程式碼，供大家參考，具體內容如下

#import "ViewController.h"
#define ImageViewCount 5
 
@interface ViewController ()<UIScrollViewDelegate>
 
@property (weak,nonatomic) IBOutlet UIScrollView *imageScrollView;
@property (weak,nonatomic) IBOutlet UIPageControl *imageViewPageControl;
@property (strong,nonatomic) NSTimer *timer;
@end
 
@implementation ViewController
 
- (void)viewDidLoad {
  [super viewDidLoad];
 
  [self addImageView2ScrollView];
  self.imageScrollView.contentSize = CGSizeMake(self.imageScrollView.frame.size.width * ImageViewCount,0);
 
  self.imageScrollView.delegate = self;
  self.imageScrollView.pagingEnabled = YES;//UIScrollView支援拖動分頁
  self.imageViewPageControl.numberOfPages = ImageViewCount;
  
  [self addScrollTimer];
}
 
- (void)rotatePic{
  int currentPageIndex = self.imageViewPageControl.currentPage;
  if(++currentPageIndex == 5){
    currentPageIndex = 0;
  }
  CGFloat offsetX = currentPageIndex * self.imageScrollView.frame.size.width;
  [UIView animateWithDuration:1 animations:^{
    self.imageScrollView.contentOffset = CGPointMake(offsetX,0);
  }];
}
 
/**新增圖片到imageScrollView*/
- (void)addImageView2ScrollView{
  CGFloat imageWidth = self.imageScrollView.frame.size.width;
  CGFloat imageHeight = self.imageScrollView.frame.size.height;
  for(int i = 0;i <= ImageViewCount;i++){
    UIImageView *imageInScroll = [[UIImageView alloc] init];
    imageInScroll.frame = CGRectMake(i * imageWidth,imageWidth,imageHeight);
    imageInScroll.image = [UIImage imageNamed:[NSString stringWithFormat:@"img_%02d",i + 1]];
    [self.imageScrollView addSubview:imageInScroll];
  }
}
 
// 正滾動時執行
- (void)scrollViewDidScroll:(UIScrollView *)scrollView{
  CGFloat offX = self.imageScrollView.contentOffset.x;//（0，0）距離content內部左上頂點的x軸長度
  NSLog(@"~~~~~~~%f ^^^^^^%f",offX,self.imageScrollView.frame.size.width);
  int currentPageIndex = (offX + .5f * self.imageScrollView.frame.size.width) / self.imageScrollView.frame.size.width;
  self.imageViewPageControl.currentPage = currentPageIndex;
}
 
- (void)addScrollTimer{
  self.timer = [NSTimer timerWithTimeInterval:2 target:self selector:@selector(rotatePic) userInfo:nil repeats:YES];
  [[NSRunLoop mainRunLoop] addTimer:self.timer forMode:NSRunLoopCommonModes];
}
 
- (void)removeScrollTimer{
  [self.timer invalidate];//釋放定時器
  self.timer = nil;
}
 
// 開始準備滾動時執行 移除定時滾動操作
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView{
  NSLog(@"~~~scrollViewWillBeginDragging");
  [self removeScrollTimer];
}
 
// 結束滾動後執行 新增定時滾動操作
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate{
  NSLog(@"~~~scrollViewDidEndDragging");
  [self addScrollTimer];
}
@end

對UIScrollView的運用，以上程式碼中有詳細註釋，需注意2點：

1.注意設定contentSize屬性。其中contentSize表示scroll內容尺寸大小

2.注意設定代理UIScrollViewDelegate，才可呼叫其中的方法

對於定時器NSTimer的運用需注意

1.線上程的loop中新增定時器

2.注意使用完成回收NSTimer

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支援我們。