UIImageView *imgView = [[UIImageView alloc]init];

[self.window addSubview:imgView];

imgView.frame = CGRectMake(250, 250, 150, 150);

 //1.设置动画的时间间隔animationDuration

    imgView.animationDuration = 1;

 //2.准备并设置动画的素材animationImages

 UIImage *img1 = [UIImage imageNamed:@"图1.tiff"];

 UIImage *img2 = [UIImage imageNamed:@"图2.tiff"];

 NSArray *array = @[img1,img2];

imgView.animationImages = array;

 //3.设置动画的重复次数

    imgView.animationRepeatCount = 100;

 //4.开始动画

[imgView startAnimating];