編譯一個簡單的Objective-C程序

Question

我想從命令行創建並編譯一個簡單的Objective-C程序。下面是代碼：

audio.h

#import <Foundation/Foundation.h> 
#include <stdlib.h> 
#import "WavReader.h" 

int main (int argc, const char *argv[]) 
{ 
    // LOG ARGUMENTS 
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; 
    NSLog (@"Running...."); 
    NSArray *args = [[NSProcessInfo processInfo] arguments]; 
    NSLog(@"Input File %@.", [args objectAtIndex:1]); 
    NSLog(@"Output File Name %@.", [args objectAtIndex:2]); 

    WavReader *wavReader = [[WavReader alloc] init]; 
    [wavReader testPrint]; 

    [pool drain]; 
    return 0; 
} 

WavReader.h

#import <Foundation/Foundation.h> 

@interface WavReader : NSObject { 

} 

- (void) testPrint; 

@end 

WavReader.m

#import "WavReader.h" 

@implementation WavReader 

- (void) testPrint 
{ 

    NSLog(@"Test print..."); 

} 
@end 

，然後我嘗試用

編譯它

gcc -framework Foundation audio.m -o audio

，我得到以下錯誤：

Undefined symbols for architecture x86_64: 
    "_OBJC_CLASS_$_WavReader", referenced from: 
     objc-class-ref in ccs07gwo.o 
ld: symbol(s) not found for architecture x86_64 
collect2: ld returned 1 exit status 

我如何能得到這個編譯？

Answer 1

您需要編譯WavReader也

gcc -framework Foundation audio.m WavReader.m -o audio 

Answer 2

編譯如下：

gcc -framework Foundation audio.m WavReader.m -o audio