如何在实现文件中的委托中调用所需的方法 [英] how to call the required method in a delegate in the implementation file

问题描述

我有两个视图控制器VC1和VC2.我通过prepareForSegue方法将值从VC1传递到VC2.当我在VC2中收到该值时，将其乘以10.然后在VC2中将该值乘以10后，我想将其返回给VC1.

I have two view controllers VC1 and VC2. I pass a value from VC1 to VC2 through prepareForSegue method. and when I receive that value in VC2 I multiply it by 10. Then after multiplying that value by 10 in VC2 I want to return it back to VC1.

要解决此问题，我将使用 Delegate .因此，我创建了 DelegateDataProcessor 类

to solve this issue, I would use Delegate. so, I created DelegateDataProcessor class

但是我不知道如何在方法 startProcessingValue

but I do not know how to call the required method processingDone in the method startProcessingValue

请看下面的代码

** DelegateDataProcessor.h **:

** DelegateDataProcessor.h**:

 #import <Foundation/Foundation.h>

 @protocol ProtocolDataProcessor <NSObject>

 @required
 - (void) processingDone;
 @end


 @interface DelegateDataProcessor : NSObject{

 id <ProtocolDataProcessor> _delegate;
 }

 @property (nonatomic, strong) id delegate;

-(void) startProcessingValue: (NSInteger) valueToBeProcessed;

@end

** DelegateDataProcessor.m **:

** DelegateDataProcessor.m**:

#import "DelegateDataProcessor.h"

@implementation DelegateDataProcessor

-(void) startProcessing:(NSInteger) value {

 value = value * 10;

//How to call the method `processingDone` here

}
@end

推荐答案

您可以通过协议将数据从VC2传递到VC1:

You can pass your data from VC2 to VC1 via a protocol:

• 向协议添加方法:

• Add a method to protocol:

-(void)getValue:(NSInteger)myInteger;

在准备segue的方法上，将VC1定义为VC2的委托

On method prepare for segue, define VC1 as VC2's delegate

当您希望从VC2返回到VC1时，可以通过传递值来调用方法getValue.

When you want come back from VC2 to VC1 call method getValue by passing your value.

我希望我能清楚地解释.

I wish that I explained clearly.

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