Question

我想实现自动更改图片库。这是我在控制器中的代码。我有一个名为image的uiimageview。我想将图像数组链接到我的图像视图，让它在几秒钟后自动更改。我该怎么办？

- (void)viewDidLoad{
     [super viewDidLoad];
     [self performSelector:@selector(changeImage) withObject:nil afterDelay:2];
}

-(void)changeImage {
     NSArray *images = [NSArray arrayWithObjects:[UIImage imageNamed:@"animated-fish-1.jpg"], [UIImage imageNamed:@"tumblr_7"], [UIImage imageNamed:@"th_nature_4.jpg"],nil];
     image.animationImages = images; 
     // how to let the array of image load and link to the perform selector??
     // what should i continue from here?
 }

Answer 1

将图像存储在ivar中

@interface YourClass : SomeSuperClass

@property (nonatomic, strong) NSArray *images;

@end

请勿在{{1}}中启动计时器，因为视图不会出现在屏幕上，所以没有任何意义 - 将其移至viewDidLoad
```
viewDidAppear:
```

Answer 2

要使用计时器为图像设置动画，请尝试使用

- (void)viewDidLoad
{
        [super viewDidLoad];
        [NSTimer scheduledTimerWithTimeInterval:1 
                                 target:self 
                               selector:@selector(animateImages) 
                               userInfo:nil 
                                repeats:YES];
        imageCount = 1;

 }

  -(void)animateImages
  {
         imageCount = imageCount + 1;
          NSString *imageName = [NSString stringWithFormat:@"image%i.png"];
          [theImage setImage:[UIImage imageNamed:imageName]];
    }

Answer 3

您应该使用NSTimer，例如，您可以使用此方法：

https://developer.apple.com/library/mac/documentation/Cocoa/Reference/Foundation/Classes/NSTimer_Class/Reference/NSTimer.html#//apple_ref/occ/clm/NSTimer/scheduledTimerWithTimeInterval:target:selector:userInfo:repeats:

此方法允许您定义要使用的选择器并每隔x秒重复

Answer 4

试试这样，采取一个全局变量索引

 - (void)viewDidLoad{
         [super viewDidLoad];
          index=0;
          NSArray *images = [NSArray arrayWithObjects:[UIImage imageNamed:@"animated-fish-1.jpg"], [UIImage imageNamed:@"tumblr_7"], [UIImage imageNamed:@"th_nature_4.jpg"],nil];
imageview.image = [images objectAtIndex:index];
          [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(changeImage) userInfo:nil repeats:YES];
    }

-(void)changeImage {
      index++;
      if(index==[images count]){
        index=0;
     }
     imageview.image = [images objectAtIndex:index];
  }

使用NSTimer更改图像数组

4 个答案: