ios - NSKeyedArchiver archivedDataWithRootObject 在传递图像模型数组时返回 nil

Question

我正在尝试使用 [NSKeyedArchiver archivedDataWithRootObject:dataArray] 保存一个包含模型的数组，该模型由图像和字符串组成；但此方法在调用此方法 2-3 次后返回 nil。仅当我尝试存档的模型包含图像时才会发生这种情况。我检查过数据数组不是零。下面是我正在使用的代码:

@implementation ImagesModel

- (id)initWithCoder:(NSCoder *)coder{
    if(self = [super init]){
        self.image = [[UIImage alloc]initWithData:[coder decodeObjectForKey:@"image"]];
        self.urlString = [coder decodeObjectForKey:@"urlString"];
    }
    return self;
}

- (void)encodeWithCoder:(NSCoder *)coder
{
    [coder encodeObject:UIImagePNGRepresentation(self.image) forKey:@"image"];
    [coder encodeObject:self.urlString forKey:@"urlString"];
}

+ (NSDictionary *)getObjectMapper {
    if (!mapperDictionary) {
        NSMutableDictionary *dictionary = [NSMutableDictionary dictionary];
        [dictionary setObject:[PropertyMapping mappingForSimpleTypeWithMappedKeyName:@"image"] forKey:@"image"];
        [dictionary setObject:[PropertyMapping mappingForSimpleTypeWithMappedKeyName:@"urlString"] forKey:@"urlString"];
        mapperDictionary = [dictionary copy];
    }
    return mapperDictionary;
}
- (NSData)ArchiveData {
    if (!dataArray){
       return NO;  //nothing to save
     }
 NSData *data = [NSKeyedArchiver archivedDataWithRootObject:dataArray]; //Return Nil
 }

Answer 1

这取决于您加载图片的方式。以下是可能对您有所帮助的答案:

How to encode a UIImage in an `NSCoder`

此外，如果您想存储 .JPEG 图像，您可能需要使用 UIImageJPEGRepresentation。