混合Objective-C和C++

Question

我正在尝试将Objective-C与C++混合使用.当我编译代码时,我得到了几个错误.

啊

#import <Cocoa/Cocoa.h>
#include "B.h"

@interface A : NSView {
    B *b;
}

-(void) setB: (B *) theB;

@end

上午

#import "A.h"

@implementation A

- (id)initWithFrame:(NSRect)frame {
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code here.
    }
    return self;
}

- (void)drawRect:(NSRect)dirtyRect {
    // Drawing code here.
}

-(void) setB: (B *) theB {
    b = theB;
}

@end

BH

#include <iostream>

class B {

    B() {
        std::cout << "Hello from C++";
    }

};

以下是错误:

/Users/helixed/Desktop/Example/B.h:1:0 /Users/helixed/Desktop/Example/B.h:1:20: error: iostream: No such file or directory
/Users/helixed/Desktop/Example/B.h:3:0 /Users/helixed/Desktop/Example/B.h:3: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'B'
/Users/helixed/Desktop/Example/A.h:5:0 /Users/helixed/Desktop/Example/A.h:5: error: expected specifier-qualifier-list before 'B'
/Users/helixed/Desktop/Example/A.h:8:0 /Users/helixed/Desktop/Example/A.h:8: error: expected ')' before 'B'
/Users/helixed/Desktop/Example/A.m:26:0 /Users/helixed/Desktop/Example/A.m:26: error: expected ')' before 'B'
/Users/helixed/Desktop/Example/A.m:27:0 /Users/helixed/Desktop/Example/A.m:27: error: 'b' undeclared (first use in this function)

Answer 1

你需要命名你的.m文件.mm.您将能够使用Objective-C编译C++代码.

因此,按照您的示例,您的AView.m文件应命名为AView.mm.这很简单.它工作得很好.我在iPhone项目中使用了很多std容器(std :: vector,std :: queue等)和遗留的C++代码而没有任何复杂性.

Answer 2

没关系,我觉得很蠢.您所要做的就是将AView.m重命名为AView.mm,以便编译器知道它的Objective-C++,并且编译没有问题.