IOS 验证码

<span style="font-size:18px;">- (void)onTapToGenerateCode:(UITapGestureRecognizer *)tap {        for (UIView *view in labelCodeNum.subviews) {        [view removeFromSuperview];    }        //生成背景颜色    float red = arc4random() % 100 / 100.0;    float green = arc4random() % 100 / 100.0;    float blue = arc4random() % 100 / 100.0;    UIColor *color = [UIColor colorWithRed:red green:green blue:blue alpha:0.2];    labelCodeNum.backgroundColor = color;        //生成文字    const int count = 5;    char data[count];    for (int x=0; x<count; x++) {        int j = '0' + (arc4random_uniform(75));        if ((j >= 58 && j <= 64) || (j >= 91 && j <= 96)) {            --x;        }else {            data[x] = (char)j;        }    }    NSString *text = [[NSString alloc] initWithBytes:data length:count encoding:NSUTF8StringEncoding];        CGSize cSize = [@"S" sizeWithAttributes:@{NSFontAttributeName:[UIFont systemFontOfSize:17.0], NSForegroundColorAttributeName:[UIColor grayColor]}];    NSInteger width = labelCodeNum.frame.size.width / text.length - cSize.width;    NSInteger height = labelCodeNum.frame.size.height - cSize.height;    CGPoint point;    float pX, pY;    for ( int i = 0, count = (int)text.length; i < count; i++) {        pX = arc4random() % width + labelCodeNum.frame.size.width / text.length * i -1;        pY = arc4random() % height;        point = CGPointMake(pX, pY);        unichar c = [text characterAtIndex:i];        UILabel *tempLabel = [[UILabel alloc] initWithFrame:CGRectMake(pX, pY, labelCodeNum.frame.size.width/4, labelCodeNum.frame.size.height)];        tempLabel.backgroundColor = [UIColor clearColor];                        //字体颜色        float red = arc4random() % 100 / 100.0;        float green = arc4random() % 100 / 100.0;        float blue = arc4random() % 100 / 100.0;        UIColor *color = [UIColor colorWithRed:red green:green blue:blue alpha:1.0];                NSString *textC = [NSString stringWithFormat:@"%C",c];        tempLabel.textColor = color;        tempLabel.text = textC;        [labelCodeNum addSubview:tempLabel];    }        //干扰线    CGContextRef context = UIGraphicsGetCurrentContext();    CGContextSetLineWidth(context, 1.0);    for (int i = 0; i < count; i++) {        red = arc4random() % 100 / 100.0;        green = arc4random() % 100 / 100.0;        blue = arc4random() % 100 / 100.0;        color = [UIColor colorWithRed:red green:green blue:blue alpha:1.0];        CGContextSetStrokeColorWithColor(context, [color CGColor]);        pX = arc4random() % (int)labelCodeNum.frame.size.width;        pY = arc4random() % (int)labelCodeNum.frame.size.height;        CGContextMoveToPoint(context, pX, pY);        pX = arc4random() % (int)labelCodeNum.frame.size.width;        pY = arc4random() % (int)labelCodeNum.frame.size.height;        CGContextAddLineToPoint(context, pX, pY);        CGContextStrokePath(context);    }    return;}</span>

效果图：