如何使 Objective-C 项目在 Ubuntu 上运行?
我的文件是:
Fraction.h
#import <Foundation/NSObject.h>
@interface Fraction: NSObject {
int numerator;
int denominator;
}
-(void) print;
-(void) setNumerator: (int) n;
-(void) setDenominator: (int) d;
-(int) numerator;
-(int) denominator;
@end
Fraction.m
#import "Fraction.h"
#import <stdio.h>
@implementation Fraction
-(void) print {
printf( "%i/%i", numerator, denominator );
}
-(void) setNumerator: (int) n {
numerator = n;
}
-(void) setDenominator: (int) d {
denominator = d;
}
-(int) denominator {
return denominator;
}
-(int) numerator {
return numerator;
}
@end
主.m
#import <stdio.h>
#import "Fraction.h"
int main( int argc, const char *argv[] ) {
// create a new instance
Fraction *frac = [[Fraction alloc] init];
// set the values
[frac setNumerator: 1];
[frac setDenominator: 3];
// print it
printf( "The fraction is: " );
[frac print];
printf( "\n" );
// free memory
[frac release];
return 0;
}
我尝试了两种编译方法:
纯 gcc:
$ sudo apt-get install gobjc gnustep gnustep-devel $ gcc `gnustep-config --objc-flags` -o main main.m -lobjc -lgnustep-base /tmp/ccIQKhfH.o:(.data.rel+0x0): undefined reference to `__objc_class_name_Fraction'
我创建了一个 GNUmakefile Makefile:
include ${GNUSTEP_MAKEFILES}/common.make TOOL_NAME = main main_OBJC_FILES = main.m include ${GNUSTEP_MAKEFILES}/tool.make
...然后运行:
$ source /usr/share/GNUstep/Makefiles/GNUstep.sh $ make Making all for tool main... Linking tool main ... ./obj/main.o:(.data.rel+0x0): undefined reference to `__objc_class_name_Fraction'
所以在这两种情况下,编译器都会卡在
undefined reference to `__objc_class_name_Fraction'
您知道如何解决这个问题吗?
最佳答案
没错。在这两种情况下,您都没有在要编译的文件列表中包含 Fraction.m
,因此它找不到类 Fraction
从评论来看,这个命令有效
gcc `gnustep-config --objc-flags` -o main *.m -lobjc -lgnustep-base
关于objective-c - 在 Linux (Ubuntu) 上编译 Objective-C 项目,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/1558462/