问在我的目标c子视图上看不到绘制文本

EN

@interface ViewController : UIViewController

@property(retain, nonatomic) UIView *subView;

@end

- (void)viewDidLoad {
    [super viewDidLoad];
    // 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

@interface CustomView : UIView

@property(retain, nonatomic)IBOutlet UIView* view;

@end

    @implementation CustomView


// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect {
    // Drawing code
    // how to draw text in here

    [super drawRect:rect];
    // Initialize a graphics context in IOS
    CGContextRef context = UIGraphicsGetCurrentContext();

    // Flip the coordinate
    CGContextTranslateCTM(context, 0, self.bounds.size.height);
    CGContextScaleCTM(context, 1.0, -1.0);

    // ???????
    // Initialize string
    CFStringRef string = CFSTR("Hello world");

    // Initialize font
    CTFontRef font = CTFontCreateWithName((CFStringRef)@"Helvetica", 16.0f, nil);

    CFStringRef keys[] = {kCTFontAttributeName};
    CFTypeRef values[] = {font};

    CFDictionaryRef attributes = CFDictionaryCreate(kCFAllocatorDefault, (const void **) &keys, (const void **) &values, sizeof(keys) / sizeof(keys[0]), &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);

    CFAttributedStringRef attrString = CFAttributedStringCreate(kCFAllocatorDefault, string, attributes);

    CFRelease(string);
    CFRelease(attributes);

    CTLineRef line = CTLineCreateWithAttributedString(attrString);

    // Set text position and draw the line into the graphics context

    CGContextSetTextPosition(context, 10, 10);

    CTLineDraw(line, context);
    CFRelease(line);
}

-(id)initWithCoder:(NSCoder *)aDecoder
{
    self = [super initWithCoder:aDecoder];

    if(self)
    {
        // 1. load the .xib file
        [[NSBundle mainBundle] loadNibNamed:@"CustomView" owner:self options:nil];

        // 2. add the subview
        self.view.backgroundColor = [UIColor redColor];
        [self addSubview:self.view];
    }

    return self;
}


@end