目的-C++轉換的std :: string到的NSString

Question

我想在我可以寫這樣的方式來寫一個客觀-C++程序：

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

然後（下面在同一.mm文件）我可以創建類的實例，然後像做：

@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 

這將有效地改變標籤的文本「myLabel」在「Hello world」

Answer 1

這應該工作：

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

它轉換std::string到const char *到NSString。

但請注意：你正在泄漏foo，所以：

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

及用途：

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