添加笔划时,文本变为不可见

Question

我有下一个问题(下面的示例代码):
我正在使用CATextLayer并NSAttributedString显示风格化的文本.一切正常,直到我为属性添加笔划.当我添加笔划时 - 文本变得不可见并且在显示中我只能看到笔划.拜托,我无法理解会发生什么,为什么我不能同时使用文字和笔画？谢谢.

UIFont* font = [UIFont fontWithName: size:];
UIColor* strokeColor = [UIColor colorWithRed: green: blue: alpha:1.f];
UIColor* foregroundColor = [UIColor colorWithRed: green: blue: alpha:1.f];
CTFontDescriptorRef fontDescriptor = CTFontDescriptorCreateWithNameAndSize(...);
CTFontRef ctFont = CTFontCreateWithFontDescriptor(...);

NSDictionary* attributes = [NSDictionary dictionaryWithObjectsAndKeys:
                            strokeWidth, kCTStrokeWidthAttributeName,
                            [strokeColor CGColor], kCTStrokeColorAttributeName,
                            ctFont, kCTFontAttributeName,
                            [foregroundColor CGColor], kCTForegroundColorAttributeName,
                            nil];

NSAttributedString* attributedText = 
[[NSAttributedString alloc] initWithString:text attributes:attributes];

CATextLayer* infoTextLayer = [[[CATextLayer alloc] init] autorelease];
infoTextLayer.string = attributedText;
...
infoTextLayer.frame = frame;
[self.layer addSublayer:infoTextLayer];

Answer 1

您的strokeWidth对于文本和笔划必须为负,对于仅笔划必须为正.来自Apple Docs:

kCTStrokeWidthAttributeName.此属性(按字体点大小的百分比解释)控制文本绘制模式:正值仅影响绘图; 中值和填充的负值.