文字加描边

1、自定义UILabel

• GC_Label.h

#import <UIKit/UIKit.h>

NS_ASSUME_NONNULL_BEGIN

@interface GC_Label : UILabel

// 设置文字描边：默认不描边，设置了描边颜色才会描边
/** 描边颜色 */
@property(nonatomic, strong) UIColor *stroke_color;
/** 描边宽度，默认为1 */
@property(nonatomic, assign) CGFloat stroke_width;

@end

NS_ASSUME_NONNULL_END

• GC_Label.m

#import "GC_Label.h"

@implementation GC_Label

- (instancetype)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
    if (self) {
        
        self.backgroundColor = Clear_Color;
        
        self.stroke_width = 1;
    }
    return self;
}

- (void)drawTextInRect:(CGRect)rect {
    
    if (self.stroke_color) {
        UIColor *temp_color = self.textColor;
        CGContextRef context = UIGraphicsGetCurrentContext();
        // 设置描边宽度
        CGContextSetLineWidth(context, self.stroke_width);
        CGContextSetLineJoin(context, kCGLineJoinRound);
        CGContextSetTextDrawingMode(context, kCGTextStroke);
        // 描边颜色
        self.textColor = self.stroke_color;
        [super drawTextInRect:rect];
        // 文本颜色
        self.textColor = temp_color;
        CGContextSetTextDrawingMode(context, kCGTextFill);
        [super drawTextInRect:rect];
    }
    else {
        [super drawTextInRect:rect];
    }
}

@end

2、使用与效果

• 使用

_title_tv = [[GC_Label alloc] init];
_title_tv.textAlignment = NSTextAlignmentCenter;
_title_tv.textColor = [UIColor redColor];

_title_tv.stroke_color = [UIColor darkGrayColor];
_title_tv.stroke_width = 5;

_title_tv.text = @"温度26℃";

• 效果