Question

我有这段代码用于测试iOS中的动画。目标是加载4个png并在UIImageView中设置它们的动画。我有一个NSMutableArray imageNames，其中我保留了图像的路径。它被正确填充。然后，当我尝试使用它创建UIImage时，它第一次工作，但之后返回nil。为什么会这样？我无法绕过这个。

for (NSInteger i = 0; i < imageNames.count; i++) {
    NSString *name = [imageNames objectAtIndex:i];
    [images addObject:[UIImage imageNamed:name]];
}

这是完整的代码：

- (void)viewDidLoad
{
    [super viewDidLoad];
    UIView *test = [[UIView alloc] initWithFrame:CGRectMake(200, 200, 50, 50)];
    test.backgroundColor = [UIColor purpleColor];
    [self.view addSubview:test];
    self.view.backgroundColor = [UIColor greenColor];
    NSMutableArray *imageNames = [[NSMutableArray alloc] initWithCapacity:4];

    NSString *basePath = @"/Users/johndoe/Desktop/soa/SoA/SoA/Models/firefly/";
    // Load images
    for (NSInteger i = 0; i < 4; i++) {
        NSMutableString *fullPath = [NSMutableString stringWithString:basePath];
        [fullPath appendFormat:@"SMALL_0000_Capa-%ld.png", i + 1];
        [imageNames addObject:fullPath];
//        [fullPath appendString:@"SMALL_0000_Capa-1.png"];

    }

    NSMutableArray *images = [[NSMutableArray alloc] init];
    for (NSInteger i = 0; i < imageNames.count; i++) {
        NSString *name = [imageNames objectAtIndex:i];
        [images addObject:[UIImage imageNamed:name]];
    }

    // Normal Animation
    UIImageView *animationImageView = [[UIImageView alloc] initWithFrame:CGRectMake(60, 95, 86, 193)];
    animationImageView.animationImages = images;
    animationImageView.animationDuration = 0.5;

    [self.view addSubview:animationImageView];
    [animationImageView startAnimating];
}

Answer 1

好吧，正如你说的那样，为了学习目的，我已经尝试了你的代码，我找到的唯一真正的问题是@rmaddy指出的问题。我不知道你的图像存储的确切位置，但我尝试将4个图像添加为资产并从中更改了代码：

NSString *basePath = @"/Users/johndoe/Desktop/soa/SoA/SoA/Models/firefly/";
// Load images
for (NSInteger i = 0; i < 4; i++) {
    NSMutableString *fullPath = [NSMutableString stringWithString:basePath];
    [fullPath appendFormat:@"SMALL_0000_Capa-%ld.png", i + 1];
    [imageNames addObject:fullPath];
}

到此：

// Load images
for (NSInteger i = 0; i < 4; i++) {
    NSString *path = [NSString stringWithFormat:@"pos%i", i];
    [imageNames addObject:path];
}

我认为它按预期工作。

Answer 2

尝试更换

animationImageView.animationImages = images;

通过这种方法：

[animationImageView setAnimationImagesWithUIImageViewSize:images];

此解决方案使用此类别提供：UIImageView+AnimationImages.m

UIImage imageNamed：name第二次返回nil

2 个答案: