终于碰到iOS对象集合深拷贝的坑

从原始数组，拆分排列组合成新数组，同时给新的数组中的模型元素追加字段，数组的容量翻倍，如果不用深拷贝，后面追加的值就把前面的值覆盖了

UnitModel *model1 = [UnitModel new];
model1.studyPageId = @"";

UnitModel *model2 = [UnitModel new];
model2.studyPageId = @"";
NSArray *modelArr = @[model1,model2];

// 直接调用mutableCopy 并没真的赋值全新的模型数组，需要model遵守NSCopy,NSMutableCopying协议，实现copyWithZone 才能copy出真正的数组

NSMutableArray <UnitModel *>*mutableModelArr = [modelArr mutableCopy];

#pragma mark - 对象深复制,M1TestArrayHelper copy处理
-(id)copyWithZone:(NSZone *)zone {
    ImageModel *model = [[self class] allocWithZone:zone];
    model.isResult = [_isResult copy];
    model.image = [_image copy];
    model.text = [_text copy];
    model.bgmArr = [_bgmArr copy];
    model.coverImageName = [_coverImageName copy];
    model.coverCount = [_coverCount copy];
    model.errorImageName = [_errorImageName copy];
    model.errorImageCount = [_errorImageName copy];
    return model;
}

-(id)mutableCopyWithZone:(NSZone *)zone {
    ImageModel *model = [[self class] allocWithZone:zone];
    model.isResult = [_isResult copy];
    model.image = [_image copy];
    model.text = [_text copy];
    model.bgmArr = [_bgmArr copy];
    model.coverImageName = [_coverImageName copy];
    model.coverCount = [_coverCount copy];
    model.errorImageName = [_errorImageName copy];
    model.errorImageCount = [_errorImageName copy];
    return model;
}

// 这里显示原始数据结构

// 这里显示目标数据结构