当传递图像模型数组时，NSKeyedArchiver archivedDataWithRootObject返回nil

Question

我尝试使用NSKeyedArchiver archivedDataWithRootObject:dataArray保存一个包含模型的数组，该数组由一个图像和一个字符串组成；但此方法在调用此方法2-3次后返回nil。只有当我尝试归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空的。下面是我使用的代码：

@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

这取决于你如何加载你的镜像。这是一个可能对你有帮助的答案：

How to encode a UIImage in an NSCoder

此外，如果您想要存储.JPEG图像，则可能需要使用UIImageJPEGRepresentation。