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我从 XCODE 4.5.2 中选择了单视图应用程序模板。我有一个 appdelegate ,一个带有 RDViewController.xib 的视图控制器,我已经制作了我的 UIView 类 Graphics 的类型。我也有 Graphics.h 和 Graphics.m(其中的 drawRect 方法)。viewController.m 中有一个 Graphics 类类型的 graphics 属性。运行时调用 drawRect 方法,但在模拟器上没有绘制任何内容。未调用 Graphics 类中的 initWithFrame 方法。RDViewController.xib 是 Graphics 的子类。

在 appdelegate 中:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.
    self.viewController = [[RDViewController alloc] initWithNibName:@"RDViewController" bundle:nil];
    self.window.rootViewController = self.viewController;
    [self.window makeKeyAndVisible];
    return YES;
}

我只在一个 ViewController 中写过:

@implementation RDViewController

@synthesize graphics;

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    [self.graphics setNeedsDisplay];
}

在 UIView 子类 Graphics

@implementation GraphicsView

- (id)initWithFrame:(CGRect)frame
{
    NSLog(@"Frame: %@", NSStringFromCGRect(frame));
    self = [super initWithFrame:frame];
    if (self) {
    }
    return self;
}

// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
    // Drawing code
    UIFont *helveticaBold;

    [UIFont fontWithName:@"HelveticaNeue-Bold" size:40.0f];

    NSString *myString = @"Test string function";

    [myString drawInRect:CGRectMake(20.0f,20.0f,40.0f,160.0f)
                withFont:helveticaBold];

    self.backgroundColor = [UIColor whiteColor];
}

运行时调用 drawRect 方法,但在模拟器上没有绘制任何内容。未调用 Graphics 类中的 initWithFrame 方法。RDViewController.xib 是 Graphics 的子类。

4

2 回答 2

1

你从来没有设置字体。做这个:

- (void)drawRect:(CGRect)rect
{
    // Drawing code
    UIFont *helveticaBold = [UIFont fontWithName:@"HelveticaNeue-Bold" size:40.0f];

    NSString *myString = @"Test string function";

    [myString drawInRect:CGRectMake(20.0f,20.0f,40.0f,160.0f)
                withFont:helveticaBold];
}

并且应该在initWithFrame:方法中设置背景颜色。

于 2013-05-05T00:54:37.193 回答
0

不要设置self.backgroundColordrawRect把它放在笔尖。

于 2013-05-05T00:53:47.983 回答