Question

请告知此代码中的错误在哪里。我不想调用方法myMethodToDoStuff。还有其他方法吗？

MyClass.h文件应如下所示（添加带注释的委托行！）

#import <BlaClass/BlaClass.h>

@class MyClass;             //define class, so protocol can see MyClass
@protocol MyClassDelegate <NSObject>   //define delegate protocol
    - (void) myClassDelegateMethod: (MyClass *) sender;  //define delegate method to be implemented within another class
@end //end protocol

@interface MyClass : NSObject {
}
@property (nonatomic, weak) id <MyClassDelegate> delegate; //define MyClassDelegate as delegate

@end

MyClass.m文件应如下所示

#import "MyClass.h"
@implementation MyClass 
@synthesize delegate; //synthesise  MyClassDelegate delegate

- (void) myMethodToDoStuff {
    [self.delegate myClassDelegateMethod:self]; //this will call the method implemented in your other class    
}

@end

在另一个类中使用你的委托（在这种情况下称为MyVC的UIViewController）MyVC.h：

#import "MyClass.h"
@interface MyVC:UIViewController <MyClassDelegate> { //make it a delegate for MyClassDelegate
}

MyVC.m：

myClass.delegate = self;          //set its delegate to self somewhere

实施委托方法

- (void) myClassDelegateMethod: (MyClass *) sender {
    NSLog(@"Delegates are great!");
}

Answer 1

似乎没有任何错误 - 这是委托的正确实现。为了调用myClassDelegateMethod:，MyClass中的某些内容需要调用myMethodToDoStuff。例如，您可以创建另一个可公开访问的方法，该方法调用myMethodToDoStuff。然后可以在MyVC中调用此方法。

@interface MyClass : NSObject {
}
@property (nonatomic, weak) id <MyClassDelegate> delegate; //define MyClassDelegate as delegate

- (void) someOtherMethod;

@end

在MyClass.m中

#import "MyClass.h"
@implementation MyClass 
@synthesize delegate; //synthesise  MyClassDelegate delegate

 - (void) myMethodToDoStuff {
    [self.delegate myClassDelegateMethod:self]; //this will call the method implemented in your other class    
}

 - (void) someOtherMethod {
     [self myMethodToDoStuff];
 }

@end

最后在MyVC中：

myClass.delegate = self;          //set its delegate to self somewhere
[myClass someOtherMethod];

这段代码中的错误在哪里？

1 个答案: