Question

我想以这样的方式编写一个Objective-C ++程序：

class foo
{
public:
foo()
{
    bar = "Hello world";
}
std::string bar;
};

然后（在同一个.mm文件下面）我可以创建该类的实例然后执行以下操作：

@interface ViewController ()
@property (weak, nonatomic) IBOutlet UILabel *myLabel;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    foo* thisWontWork = new foo();
    self.myLabel.text = foo.bar; //this doesn't work obviously

// Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}

@end

这将有效地将标签'myLabel'的文本更改为“Hello world”

Answer 1

这应该有效：

self.myLabel.text = @(foo->bar.c_str());

将std::string转换为const char *至NSString。

但请注意：您正在泄漏foo，所以：

@interface ViewController ()
{
    foo _foo;
}
@property (weak, nonatomic) IBOutlet UILabel *myLabel;
@end

并使用：

self.myLabel.text = @(_foo.bar.c_str());

Objective-C ++将std :: string转换为NSString

1 个答案: