在Objective C中调用另一个类的方法 [英] Calling a method from another class in Objective C

问题描述

我有两个类，比如说A类和B类。
类A在类A中创建。
我有一个类A中的方法，需要在类A和类A中执行在A类本身调用该方法很好。但我不知道在类B中调用该方法。
我已经尝试将该方法声明为静态，但是由于我不能在静态方法中使用实例变量，我认为使用代理将是一个好主意。由于我来自C＃背景，我不确定在Objective C中使用它。从概念上讲，我已经在C＃中实现了我需要的，如下所示。只想知道目标C中的等价物。

  class A 
 {
 
 public A（）
 {
 B myclass = new B（（）=> calculate（））; 
} 
 
 public void calculate（）
 {
 // todo 
} 
} 
 
 class B 
 {
 public B（Action calculate）
 {
 calculate（）; 
} 
} 
  

可以使用协议来执行此操作。 p>

解决方案

我刚刚碰巧在研究时看到这篇文章。以下是一个示例代码：

ClassA.h文件：

  #import< Foundation / Foundation.h> 
 #importClassB.h
 
 @interface ClassA：NSObject&ClassBDelegate> 
 @end 
  

ClassA.m文件：

  #importClassA.h
 @implementation ClassA 
  - （void）createAnInstanceOfClassB 
 {
 ClassB * myClassB = [[ClassB alloc] init]; //创建一个ClassB的实例
 myClassB.delegate = self; //将self设为委托
 // [myClassB optionalClassBMethod]; //这是您的问题的可选项。如果你还要ClassA从ClassB 
 
 
  - （void）计算
 {
 NSLog（@Do calculate thing！）; //计算可以从ClassB或ClassA 
 
 
 @end 
  

ClassB.h文件：

  #import< Foundation / Foundation.h> 
 @protocol ClassBDelegate< NSObject> 
  - （void）calculate; //方法从ClassA 
 @end 
 
 @interface ClassB：NSObject 
 @property（assign）id&ClassBDelegate>代表; 
 //  - （void）optionalClassBMethod; //这是你的问题的选择。如果您也希望ClassA从ClassB调用方法
 @end 
  

ClassB.m文件：

  #importClassB.h
 @implementation ClassB 
 @synthesize delegate; 
 
  - （void）whateverMethod 
 {
 [self.delegate calculate]; //调用方法计算在ClassA 
} 
 
 //  - （void）optionalClassBMethod //这是您的问题的可选项。如果您也希望ClassA从ClassB 
 // {
 // NSLog（@optionalClassBMethod）调用方法; 
 // [self whateverMethod]; 
 //} 
 
 @end 
  

I have 2 classes, say class A and class B. Class B is created in class A. I have a method in class A, which needs to be executed in both class A and class B. Calling the method in class A itself is fine. But I am not sure about calling the method in class B. I have tried declaring the method as static, but since I can't use instance variables inside the static method, I think using delegates would be a good idea. Since I am from a C# background, I am not sure about using it in Objective C. Conceptually, I have implemented what I need in C# as shown below. Just wanted to know what the equivalent of it would be in Objective C.

class A
{

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

    public void calculate()
    {
        // todo
    }
}

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

Is it possible to do this using protocols.

解决方案

I just happened to see this post while researching. Here is a sample code:

ClassA.h file:

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

@interface ClassA : NSObject <ClassBDelegate>
@end

ClassA.m file:

#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 file:

#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 file:

#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

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