ios drawRect NSString 绘制

- (void)drawRectFor7
{
#if __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_7_0
    
    UIFont *font = [UIFont boldSystemFontOfSize:_fontSize];
    
    NSDictionary *attributes = nil;
    NSDictionary *strokeAttributes = nil;
    if (_useLightText)
    {
        strokeAttributes = [NSDictionary dictionaryWithObjectsAndKeys:font, NSFontAttributeName, _strokeColor, NSStrokeColorAttributeName, @-10.0, NSStrokeWidthAttributeName, nil];
        
        attributes = [NSDictionary dictionaryWithObjectsAndKeys:font, NSFontAttributeName, _lightColor, NSForegroundColorAttributeName, nil];
    }
    else
    {
        attributes = [NSDictionary dictionaryWithObjectsAndKeys:font, NSFontAttributeName, _normalColor, NSForegroundColorAttributeName, nil];
    }
    
    // draw text
    int i = 0;
    double unitStartX = 0.0;
    for (NSString *str in _strings)
    {
        
        CGSize size = [str sizeWithAttributes:attributes];
        double startX = _segmentLengthInPixels * i - size.width / 2.0 + kScaleSegmentMargin;
        
        ++i;
        
        // draw units string position
        if (_withUnits && i == _strings.count)
        {
            startX = unitStartX;
        }
        else
        {
            unitStartX = _segmentLengthInPixels * (i - 1) + size.width / 2.0 + kScaleSegmentMargin * 2;
        }
        
        if (strokeAttributes != nil)
        {
            [str drawAtPoint:CGPointMake(startX, 0) withAttributes:strokeAttributes];
        }
        
        [str drawAtPoint:CGPointMake(startX, 0) withAttributes:attributes];
    }
    
#endif
}

- (void)drawRectFor6
{
    // obtain current context
    CGContextRef context = UIGraphicsGetCurrentContext();
    
    // save context state first
    CGContextSaveGState(context);
    
    // set text color in context
    if (_useLightText)
    {
        CGContextSetFillColorWithColor(context, _lightColor.CGColor);
    }
    else
    {
        CGContextSetFillColorWithColor(context, _normalColor.CGColor);
    }
    
    UIFont *font = [UIFont boldSystemFontOfSize:_fontSize];
    
    // draw text
    int i = 0;
    double unitStartX = 0.0;
    for (NSString *str in _strings)
    {

        CGSize size = [str sizeWithFont:font];
        double startX = _segmentLengthInPixels * i - size.width / 2.0 + kScaleSegmentMargin;
        
        ++i;
        
        // draw units string position
        if (_withUnits && i == _strings.count)
        {
            startX = unitStartX;
        }
        else
        {
            unitStartX = _segmentLengthInPixels * (i - 1) + size.width / 2.0 + kScaleSegmentMargin * 2;
        }

        //draw stroke
        if (_useLightText)
        {
            CGContextSaveGState(context);
            CGContextSetTextDrawingMode(context, kCGTextStroke);
            CGContextSetStrokeColorWithColor(context, _strokeColor.CGColor);
            [str drawAtPoint:CGPointMake(startX, 0) withFont:font];
            CGContextRestoreGState(context);
        }
        
        [str drawAtPoint:CGPointMake(startX, 0) withFont:font];
        
    }
    
    // restore context state
    CGContextRestoreGState(context);
}

userLightText模式下绘制白底黑边字符串，普通模式下绘制黑色字。

ios7 下使用 

- (void)drawAtPoint:(CGPoint)point withAttributes:(NSDictionary *)attrs  进行绘制。

需要定义attributes，对样式进行定义。

ios7 之前使用 

- (CGSize)drawAtPoint:(CGPoint)point withFont:(UIFont *)font 绘制。