应用程序在4S上工作正常,但由于SIGABRT而在3G上崩溃

Question

当用户第一次启动应用程序时,他会弹出一个并且必须保存图像.它适用于模拟器和4S.但是当我用我的3G开始它时,一旦我选择了一张照片就会给我一个SIGABRT错误.我假设它是因为图片的大小过于挑选并因此声称所有的公羊 - 但这是相当奇怪的,因为我把它做得更小.这是代码:

- (void)viewDidLoad
{ 
    [super viewDidLoad];
    if ([[NSUserDefaults standardUserDefaults] objectForKey:@"bild"] == nil) { 
        picker = [[UIImagePickerController alloc] init];
        picker.delegate = self;
        picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
        [self presentModalViewController:picker animated:YES];
    }
}

- (void)imagePickerController:(UIImagePickerController *) Picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
    double compressionRatio=1;
    NSData *imageData=UIImageJPEGRepresentation([info objectForKey:@"bild"],compressionRatio);
    while ([imageData length]>5000) { 
        compressionRatio=compressionRatio*0.20;
        imageData=UIImageJPEGRepresentation([info objectForKey:@"bild"],compressionRatio);
    }

    UIImage *yourUIImage;
    yourUIImage = [info objectForKey:UIImagePickerControllerOriginalImage];
    imageData = [NSKeyedArchiver archivedDataWithRootObject:yourUIImage];
    [[NSUserDefaults standardUserDefaults] setObject:imageData forKey:@"bild"];
    [[NSUserDefaults standardUserDefaults] synchronize];

    [self dismissModalViewControllerAnimated:YES];
}

我在此行得到SIGABRT错误imageData = [NSKeyedArchiver archivedDataWithRootObject:yourUIImage];

我应该使用其他方法来调整图像大小吗？或者我应该将其保存为本地文件并在应用程序启动时检索它？(如果它是可能的)

Answer 1

您正在使用NSCoding将UIImage存档为NSData对象.
在iOS5之前,UIImage没有实现NSCoding的方法.你不能archivedDataWithRootObject:在iOS5之前使用UIImages.
这就是你在iPhone 3G上获得例外的原因.

这只是一个非常有根据的猜测,因为我无法通过文档或设备上的测试来确认,但是有很多问题和论坛帖子询问如何在UIImage上实现NSCoding.

并且根本不会调用整个代码块,因为[info objectForKey:@"bild"]它将返回nil.信息字典不包含密钥bild的对象.文档UIImagePickerControllerDelegate_Protocol包含有效密钥列表

NSData *imageData=UIImageJPEGRepresentation([info objectForKey:@"bild"],compressionRatio);
while ([imageData length]>5000) { 
    compressionRatio=compressionRatio*0.20;
    imageData=UIImageJPEGRepresentation([info objectForKey:@"bild"],compressionRatio);
}

你可能想要使用这样的东西:

NSData *data;
if ([[UIImage class] conformsToProtocol:@protocol(NSCoding)]) {
    // >= iOS5
    data = [NSKeyedArchiver archivedDataWithRootObject:image];
    // save so you know it's an archived UIImage object
}
else {
    // < iOS5
    data = /* your UIImageJPEGRepresentation method but this time with the key UIImagePickerControllerOriginalImage instead of "bild" */
    // save so you know it's raw JPEG data
}