Question

@interface Father : NSObject
-(void)show;
@end

@interface Child : Father
-(void)show;
@end
- (instancetype)init
{
  self = [super init];
  [self show];
  return self;
}

- (void)show
{
  NSLog(@"I am father");
}
@end

@implementation Child

- (instancetype)init
{
  self = [super init];
  [self show];
  return self;
}

- (void)show
{
  NSLog(@"I am child");
}

@end

- (void)viewDidLoad
{
  Child *child = [[Child alloc] init];
}

Output: 
I am child
I am child

从代码和输出中，我们可以看到父亲的[self show]实际上是[child show]。当孩子覆盖方法时，有没有办法在父亲中调用父方法，换句话说，有没有办法选择父方法或子方法。

Answer 1

@implementation Child

- (instancetype)init
{
  self = [super init];
  [self show];
  return self;
}

- (void)show
{
  NSLog(@"I am child");
  [super show];  // This line call show method of father class
}

@end

- (void)viewDidLoad
{
  Child *child = [[Child alloc] init];
}

尝试以上代码。

浏览Objective-C doc https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/ProgrammingWithObjectiveC/WorkingwithObjects/WorkingwithObjects.html

Answer 2

您可以使用

调用超类方法

[super show]; //call this method from within child class

此方法执行调用show中的Super Class方法（在我们的案例中为父类）

希望这有帮助

Objective-c如何在子类中调用父方法中的父方法

2 个答案: