自定义三个model类分别为OneModel、TwoModel、AllModel
OneModel.h为
@property(nonatomic ,copy)NSString *oneName;
TwoModel.h为
@property(nonatomic ,copy)NSString *twoName;
AllModel.h为
@property(nonatomic ,strong)OneModel *oneModel;
@property(nonatomic ,strong)TwoModel *twoModel;
接下来要对AllModel的实例化对象赋值
AllModel *model = [AllModel new];
if(model.oneModel.oneName == nil){
model.oneModel.oneName = @"123";
}else{
[model.oneModel setValue:@"abc" forKey:@"oneName"];
}
model.twoModel.twoName = @"789";
[model.twoModel setValue:@"xyz" forKey:@"twoName"];
以上对model赋值全为nil。
原因，没有给对象初始化。如果要进行赋值：
AllModel *model = [AllModel new];
OneModel *model1 = [OneModel new];
TwoModel *model2 = [TwoModel new];
model1.oneName = @"123";
model2.twoName = @"789";
model.oneModel = model1;
model.twoModel = model2;
