最近做了個需求滚躯，需要使用字體帶邊框和漸變色，顯示效果如下：

image.png

主要方式柳畔，封裝一個自定義UILabel代碼馍管，需要為字體加邊框，并且需要設(shè)置豐富顏色薪韩，如果是數(shù)字可以使用多張圖片切換确沸，但是也可以寫成UIlabel比較通用性，代碼如下：

@interface StrokeLabel : UILabel

/** 描多粗的邊*/

@property (nonatomic, assign) NSInteger outLineWidth;

/** 外輪顏色*/

@property (nonatomic, strong) UIColor *outLinetextColor;

/** 里面字體默認顏色*/

@property (nonatomic, strong) UIColor *labelTextColor;

@end

@implementation StrokeLabel

- (void)drawRect:(CGRect)rect {
    
    CGSize textSize = [self.text boundingRectWithSize:rect.size options:NSStringDrawingUsesFontLeading attributes:@{NSFontAttributeName : self.font} context:nil].size;
    CGFloat text_width = textSize.width;
    CGFloat text_height = textSize.height;
    
    CGContextRef context = UIGraphicsGetCurrentContext();
    // 獲取文字mask
    [self.text drawInRect:self.bounds withAttributes:@{NSFontAttributeName : self.font}];

    CGImageRef textMask = CGBitmapContextCreateImage(context);

    // 清空畫布
    CGContextClearRect(context, rect);

    // 添加描邊
    CGSize shadowOffset = self.shadowOffset;
    CGContextSetLineWidth(context, self.outLineWidth);//字體邊緣的寬度
    CGContextSetLineJoin(context, kCGLineJoinRound);
    CGContextSetTextDrawingMode(context, kCGTextFillStroke);
    self.textColor = [UIColor blackColor];//字體邊緣加的顏色
    [super drawTextInRect:rect];
    CGContextSetTextDrawingMode(context, kCGTextStroke);
    self.textColor = self.outLinetextColor;
    self.shadowOffset = CGSizeMake(0, 10);
    [super drawTextInRect:rect];
    self.shadowOffset = shadowOffset;

    // 設(shè)置蒙層
    CGContextTranslateCTM(context, (rect.size.width-text_width)/2.0, self.bounds.size.height + self.bounds.size.height/2 - text_height/2);
    CGContextScaleCTM(context, 1.0, -1.0);
    CGContextClipToMask(context, rect, textMask);

    // 繪制漸變
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGFloat locations[] = {0,0.5,0.5,1};
    CGFloat colors[] = {
        0.5,0.0,0.4,1.0,
        0.5,0.0,0.4,1.0,
        1.0,0.0,0.0,1.0,
        1.0,0.0,0.0,1.0
    };
    CGGradientRef gradient=CGGradientCreateWithColorComponents(colorSpace, colors, locations, 4);
    CGPoint start = CGPointMake(0, self.bounds.size.height - text_height);
    CGPoint end = CGPointMake(0, self.bounds.size.height);
    CGContextDrawLinearGradient(context, gradient, start, end, kCGGradientDrawsBeforeStartLocation);

    // 釋放
    CGColorSpaceRelease(colorSpace);
    CGGradientRelease(gradient);
}

@end

自定義控件使用方法如下：

self.strokeLabel = [[StrokeLabel alloc] initWithFrame:CGRectMake(20, 250, 300, 100)];
self.strokeLabel.textAlignment = NSTextAlignmentCenter;
self.strokeLabel.outLineWidth = 5;
self.strokeLabel.outLinetextColor = UIColor.systemGreenColor;
self.strokeLabel.text = @"1234567890";
self.strokeLabel.font = [UIFont systemFontOfSize:40 weight:UIFontWeightHeavy];
[self.view addSubview:self.strokeLabel];