iOS-自定义UILable实现文本渐变色

//.h文件

#import <UIKit/UIKit.h>

 

NS_ASSUME_NONNULL_BEGIN

 

@interface SFYStrokeLabel : UILabel

 

/** 描多粗的边*/

@property (nonatomic, assign) NSInteger outLineWidth;

 

/** 外轮颜色*/

@property (nonatomic, strong) UIColor * outLinetextColor;

 

/** 里面字体默认颜色*/

@property (nonatomic, strong) UIColor * labelTextColor;

 

@end

 //.m文件

#import "SFYStrokeLabel.h"

 

@implementation SFYStrokeLabel

 

- (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();

    // 获取文字mask

    [self.text drawInRect:self.bounds withAttributes:@{NSFontAttributeName : self.font}];

 

    CGImageRef textMask = CGBitmapContextCreateImage(context);

 

    // 清空画布

    CGContextClearRect(context, rect);

 

    // 添加描边

    CGSize shadowOffset = self.shadowOffset;

    CGContextSetLineWidth(context, self.outLineWidth);//字体边缘的宽度

    CGContextSetLineJoin(context, kCGLineJoinRound);

    CGContextSetTextDrawingMode(context, kCGTextFillStroke);

    self.textColor = [UIColor blackColor];//字体边缘加的颜色

    [super drawTextInRect:rect];

    CGContextSetTextDrawingMode(context, kCGTextStroke);

    self.textColor = self.outLinetextColor;

    self.shadowOffset = CGSizeMake(0, 10);

    [super drawTextInRect:rect];

    self.shadowOffset = shadowOffset;

 

    // 设置蒙层

    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);

 

    // 绘制渐变

    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);

 

    // 释放

    CGColorSpaceRelease(colorSpace);

    CGGradientRelease(gradient);

}

 

/*

// Only override drawRect: if you perform custom drawing.

// An empty implementation adversely affects performance during animation.

- (void)drawRect:(CGRect)rect {

    // Drawing code

}

*/

 

@end

 //viewcontroller调用

SFYStrokeLabel* strokeLabel = [[SFYStrokeLabel alloc] initWithFrame:CGRectMake(20, [UIScreen mainScreen].bounds.size.height / 2 - 100, [UIScreen mainScreen].bounds.size.width-40, 200)];

    strokeLabel.textAlignment = NSTextAlignmentCenter;

    strokeLabel.outLineWidth = 5;

    strokeLabel.outLinetextColor = UIColor.systemGreenColor;

    strokeLabel.text = @"❤️喜欢就点个关注吧👍";

    strokeLabel.font = [UIFont systemFontOfSize:26 weight:UIFontWeightHeavy];

    [self.view addSubview:strokeLabel];