iphone - 在 Objective C 中调用另一个类的方法

Question

我有 2 个类(class)，比如 A 类和 B 类。B类是在A类中创建的。我在A类中有一个方法，需要在A类和B类中都执行，调用A类本身的方法就可以了。但是我不确定在 B 类中调用该方法。我试过将方法声明为静态方法，但由于我不能在静态方法中使用实例变量，我认为使用委托(delegate)是个好主意。由于我来自 C# 背景，我不确定是否在 Objective C 中使用它。从概念上讲，我已经在 C# 中实现了我需要的东西，如下所示。只是想知道它在 Objective C 中的等价物是什么。

class A
{

    public A()
    {
        B myclass = new B(() => calculate());                
    }

    public void calculate()
    {
        // todo
    }
}

class B
{
    public B(Action calculate)
    {
        calculate();
    }
}

是否可以使用协议(protocol)来做到这一点。

Answer 1

我刚刚在研究时偶然看到这篇文章。这是一个示例代码:

A类.h文件:

#import <Foundation/Foundation.h>
#import "ClassB.h"

@interface ClassA : NSObject <ClassBDelegate>
@end

ClassA.m 文件:

#import "ClassA.h"
@implementation ClassA
-(void)createAnInstanceOfClassB
{
    ClassB *myClassB = [[ClassB alloc]init];  //create an instance of ClassB
    myClassB.delegate = self;  //set self as the delegate
//    [myClassB optionalClassBMethod];  //this is optional to your question.  If you also want ClassA to call method from ClassB
}

-(void)calculate
{
    NSLog(@"Do calculate thing!");  // calculate can be called from ClassB or ClassA
}

@end

ClassB.h文件:

#import <Foundation/Foundation.h>
@protocol ClassBDelegate <NSObject>
-(void)calculate;   //method from ClassA
@end

@interface ClassB : NSObject
@property (assign) id <ClassBDelegate> delegate;
//-(void)optionalClassBMethod;   //this is optional to your question.  If you also want ClassA to call method from ClassB
@end

ClassB.m 文件:

#import "ClassB.h"
@implementation ClassB
@synthesize delegate;

-(void)whateverMethod
{
    [self.delegate calculate];  // calling method "calculate" on ClassA
}

//-(void)optionalClassBMethod   //this is optional to your question.  If you also want ClassA to call method from ClassB
//{
//    NSLog(@"optionalClassBMethod");
//    [self whateverMethod];
//}

@end