如何解决“糟糕的接收器类型”错误

我正在制作一个应用程序，允许您设置名称和边数，然后应用程序将自动计算形状名称。我被要求将NSNumber的边数改为int。我已经这样做了，但现在我得到一个错误，说“坏接收器类型”。我能做些什么来纠正这一情况，但保留副财产的数量为int？如何解决“糟糕的接收器类型”错误

这是该类我的头文件

#import <Foundation/Foundation.h> 

@interface shape : NSObject 

@property int *numberOfSides; 
@property (nonatomic, strong) NSString *name; 
@property (nonatomic, strong) NSString *colour; 

@property (nonatomic, strong) NSString *calculatedName; 

void waitOnCR (void); 
- (NSString *)calculatedName; 

@end

这是类的实现文件

- (NSString *)calculatedName { 
    if ([self.numberOfSides isEqual: @3]) { 
     return self.name = @"Triangle"; 
    } 
    else if([self.numberOfSides isEqual: @4]) { 
     return self.name = @"Square"; 
    } 
    else if([self.numberOfSides isEqual: @5]) { 
     return self.name = @"Pentagon"; 
    } 
    else if([self.numberOfSides isEqual: @6]) { 
     return self.name = @"Hexagon"; 
    } 
    else if([self.numberOfSides isEqual: @7]) { 
     return self.name = @"Heptagon"; 
    } 
    else if([self.numberOfSides isEqual: @8]) { 
     return self.name = @"Octagon"; 
    } 

    return [NSString stringWithFormat:@"%@", self.name ]; 
} 

@end

这是主要的文件

NSLog(@"Enter a number from between 3-8"); 

int user; 

scanf("%d" , &user); 

switch (user) { 
    case 3: 
    { 
     shape *myShape = [[shape alloc]init]; 
     [myShape setNumberOfSides:3]; 
     [myShape setColour:@"Red"]; 
     id s2 = [myShape calculatedName]; 


     NSLog(@"The %@ shape has %i sides and is called a %@", [myShape colour], [myShape numberOfSides], s2); 
     break; 
    } 
    case 4: 
    { 
     { 
      shape *myShape = [[shape alloc]init]; 
      [myShape setNumberOfSides:@4]; 
      [myShape setColour:@"Blue"]; 
      id s2 = [myShape calculatedName]; 

      NSLog(@"The %@ shape has %@ sides and is called a %@", [myShape colour], [myShape numberOfSides], s2); 
      break; 
     } 
    case 5: 
     { 
      shape *myShape = [[shape alloc]init]; 
      [myShape setNumberOfSides:@5]; 
      [myShape setColour:@"Orange"]; 
      id s2 = [myShape calculatedName]; 

      NSLog(@"The %@ shape has %@ sides and is called a %@", [myShape colour], [myShape numberOfSides], s2); 
      break; 
     } 
    case 6: 
     { 
      shape *myShape = [[shape alloc]init]; 
      [myShape setNumberOfSides:@6]; 
      [myShape setColour:@"Purple"]; 
      id s2 = [myShape calculatedName]; 

      NSLog(@"The %@ shape has %@ sides and is called a %@", [myShape colour], [myShape numberOfSides], s2); 
      break; 
     } 
    case 7: 
     { 
      shape *myShape = [[shape alloc]init]; 
      [myShape setNumberOfSides:@7]; 
      [myShape setColour:@"Green"]; 
      id s2 = [myShape calculatedName]; 

      NSLog(@"The %@ shape has %@ sides and is called a %@", [myShape colour], [myShape numberOfSides], s2); 
      break; 
     } 
    case 8: 
     { 
      shape *myShape = [[shape alloc]init]; 
      [myShape setNumberOfSides:@8]; 
      [myShape setColour:@"Pink"]; 
      id s2 = [myShape calculatedName]; 

      NSLog(@"The %@ shape has %@ sides and is called a %@", [myShape colour], [myShape numberOfSides], s2); 
      break; 
     } 

    } 
    default: 
     NSLog(@"Shape not found!"); 
     break; 
}

来源

2013-09-26 H41RD

气味像一些任务（理论上这样会很好，但这里的问题是基本的......即时通讯投票结束>常见问题解答：“询问代码的问题必须证明对所解决问题的最小理解。 –

的numberOfSides不一个对象，而不是一个基本的数据类型，而不是：

int *numberOfSides;

你真的想：

int numberOfSides;

而不是你的if之类的语句

if ([self.numberOfSides isEqual: @3]) ...

你想

if (self.numberOfSides == 3) ...

而且，你的电话一样：

[myShape setNumberOfSides:@4];

应该是：

[myShape setNumberOfSides:4];

（你这样做是为了 “3”，而不是休息。）

底线，替换所有的数字文字（这是一个NSNumber对象）整数，并将isEqual替换为==。

来源

2013-09-26 13:07:36 Rob

如何解决“糟糕的接收器类型”错误

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