ios - 不完整的实现 - Xcode 警告

Question

我刚刚开始进行 iOS 开发，由于警告而有点卡住了。构建成功，但这个警告让我很困扰。我检查了其他一些答案，但无法弄清楚出了什么问题。

Waring - 不完整的实现

复数.h

#import <Foundation/Foundation.h>

@interface ComplexNumbers : NSObject

-(void) setReal: (double)a;
-(void) setImaginary: (double)b;
-(void) print; // display as a + bi

-(double) real;
-(double) imaginary;

@end

复数.m

#import "ComplexNumbers.h"

@implementation ComplexNumbers  // Incomplete implementation

{
double real;
double imaginary;
}

-(void) print
{
    NSLog(@"%f + %fi",real,imaginary);
}
-(void) setReal:(double)a
{
    real = a;
}
-(void) setImaginary:(double)b
{
    imaginary = b;
}

@end

Answer 1

你的问题是你的界面说有real和imaginary方法，但你还没有实现这些。更好的是，通过将它们定义为属性，让编译器为您合成setterreal和imaginarygetter 方法，并且您的代码大大简化：

@interface ComplexNumbers : NSObject

@property (nonatomic) double real;
@property (nonatomic) double imaginary;

-(void) print; // display as a + bi

@end

和

@implementation ComplexNumbers

-(void) print
{
    NSLog(@"%f + %fi", self.real, self.imaginary);
}

@end

Answer 2

您还没有实现这些属性获取器：

-(double) real;
-(double) imaginary;

您可以实现它们：

-(double) real { return _real; }
-(double) imaginary { return _imaginary; }

或者让编译器通过在标题中将它们声明为属性来为您完成：

@property(nonatomic) double real;
@property(nonatomic) double imaginary;

在 .m 文件中：

@synthesize real = _real, imaginary = _imaginary;

其中 _ 是实例成员。

Answer 3

试试这个，

#import "ComplexNumbers.h"

@implementation ComplexNumbers  // Incomplete implementation

{
double real;
double imaginary;
}

-(void) print
{
  NSLog(@"%f + %fi",real,imaginary);
}

-(void) setReal:(double)a
{
real = a;
 }
-(void) setImaginary:(double)b

{
imaginary = b;
}
 -(double) real
{
   return real;
}
-(double) imaginary
{
   return imaginary;
}

@end