UILabel设置背景色/阴影/描边

效果图:

QQ20171122-113317.png

通过NSMutableAttributedString设置UILabel中文字的背景色:

//设置字体背景颜色
    NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc]init];
    NSString *str1 = @"背景色";
    NSDictionary *dictAttr1 = @{NSBackgroundColorAttributeName:[UIColor cyanColor]};
    NSAttributedString *attr1 = [[NSAttributedString alloc]initWithString:str1 attributes:dictAttr1];
    [attributedString appendAttributedString:attr1];

    UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(100, 100, 200, 50)];
    label.textColor = [UIColor blueColor];
    label.attributedText = attributedString;
    [self.view addSubview:label];

设置阴影有两种方法:
方法一:

// 通过layer层设置阴影
    UILabel *label2 = [[UILabel alloc] initWithFrame:CGRectMake(100, 150, 200, 50)];
    label2.text = @"layer层设置阴影";
    label2.textColor = [UIColor blueColor];
    
    label2.layer.shadowColor = [UIColor blackColor].CGColor;
    label2.layer.shadowOffset = CGSizeMake(0, 0);
    label2.layer.shadowOpacity = 1;
    [self.view addSubview:label2];

方法二:

// 通过富文本设置阴影
    NSShadow *shadow = [[NSShadow alloc] init];
    shadow.shadowBlurRadius = 10.0;
    shadow.shadowOffset = CGSizeMake(0, 0);
    shadow.shadowColor = [UIColor blackColor];
    NSAttributedString *attributedText = [[NSAttributedString alloc] initWithString:@"富文本设置阴影" attributes:@{NSShadowAttributeName:shadow}];
    
    UILabel *label3 = [[UILabel alloc] initWithFrame:CGRectMake(100, 200, 200, 50)];
    label3.textColor = [UIColor blueColor];
    label3.attributedText = attributedText;
    [self.view addSubview:label3];

描边需要继承自UILabel以后重载- (void)drawRect:(CGRect)rect方法:

- (void)drawRect:(CGRect)rect {
    
    CGSize shadowOffset = self.shadowOffset;
    UIColor *textColor = self.textColor;
    
    CGContextRef ref = UIGraphicsGetCurrentContext();
    CGContextSetLineWidth(ref, 1);
    CGContextSetLineJoin(ref, kCGLineJoinRound);
    
    CGContextSetTextDrawingMode(ref, kCGTextStroke);
    self.textColor = [UIColor redColor];
    [super drawRect:rect];
    
    CGContextSetTextDrawingMode(ref, kCGTextFill);
    self.textColor = textColor;
    self.shadowOffset = CGSizeMake(0,0);
    [super drawRect:rect];
    
    self.shadowOffset = shadowOffset;
}

描边的使用:

// 描边
    HYZLabel *label4 = [[HYZLabel alloc] initWithFrame:CGRectMake(100, 250, 200, 50)];
    label4.text = @"描边啊描边";
    label4.textColor = [UIColor blueColor];
    label4.shadowOffset = CGSizeMake(0, 0);
    [self.view addSubview:label4];