iOS开发-图形验证码绘图实例

前言:

公司项目需求获取短信验证码前需要输入图形验证码防止羊毛客使用脚本批量注册平台账号
想了想还是自己重新实现了一下.

思路

1.容器创建
    1.1 代码创建
    1.2 nib文件使用 
2.创建验证码字符串 
2.绘图
    2.1 绘字
    2.2 绘干扰线 
4.点击刷新机制

代码实例

//
//  ImageCodeView.h
//  VerCodeView
//
//  Created by hpjr on 2016/12/22.
//  Copyright © 2016年 sands. All rights reserved.
//
#import \"ImageCodeView.h\"

#define CODE_LENGTH 4
#define ARCNUMBER arc4random() % 100 / 100.0
#define ARC_COLOR [UIColor colorWithRed:ARCNUMBER green:ARCNUMBER blue:ARCNUMBER alpha:0.2]

@implementation ImageCodeView

//初始化
- (instancetype)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        [self setupUI];
    }
    return self;
}

//兼容nib使用
- (void)awakeFromNib{
    [super awakeFromNib];
    [self setupUI];
}

//设置默认参数
- (void)setupUI{

    self.CodeArr = @[@\"0\",@\"1\",@\"2\",@\"3\",@\"4\",@\"5\",@\"6\",@\"7\",@\"8\",@\"9\",@\"A\",@\"B\",@\"C\",@\"D\",@\"E\",@\"F\",@\"G\",@\"H\",@\"I\",@\"J\",@\"K\",@\"L\",@\"M\",@\"N\",@\"O\",@\"P\",@\"Q\",@\"R\",@\"S\",@\"T\",@\"U\",@\"V\",@\"W\",@\"X\",@\"Y\",@\"Z\",@\"a\",@\"b\",@\"c\",@\"d\",@\"e\",@\"f\",@\"g\",@\"h\",@\"i\",@\"j\",@\"k\",@\"l\",@\"m\",@\"n\",@\"o\",@\"p\",@\"q\",@\"r\",@\"s\",@\"t\",@\"u\",@\"v\",@\"w\",@\"x\",@\"y\",@\"z\"];
    
    UITapGestureRecognizer* changeCode = [[UITapGestureRecognizer alloc]initWithTarget:self
                                                                                action:@selector(changeCode)];
    [self addGestureRecognizer:changeCode];
    
    self.backgroundColor = ARC_COLOR;
    
    [self getStrCode];
}

//随机生成验证码字符串
- (void)getStrCode{
    self.backgroundColor = ARC_COLOR;
    
    NSMutableString* tmpStr = [[NSMutableString alloc] initWithCapacity:5];;
    for (int i = 0; i < CODE_LENGTH; i++) {
        NSInteger index = arc4random() % (self.CodeArr.count-1);
        [tmpStr appendString:[self.CodeArr objectAtIndex:index]];
    }
    self.CodeStr = [NSString stringWithFormat:@\"%@\",tmpStr];
}

//刷新验证码
- (void)changeCode{
    [self getStrCode];
    [self setNeedsDisplay];
}

- (void)drawRect:(CGRect)rect {
    [super drawRect:rect];
    CGSize cSize = [@\"A\" sizeWithAttributes:@{NSFontAttributeName:[UIFont systemFontOfSize:20]}];//计算单个字所需空间
    int width = rect.size.width / self.CodeStr.length - cSize.width;//间距
    int height = rect.size.height - cSize.height;//可浮动高度
    CGPoint point;
    //绘码
    float pX, pY;
    for (int i = 0; i < self.CodeStr.length; i++)
    {
        pX = arc4random() % width + rect.size.width / self.CodeStr.length * i;
        pY = arc4random() % height;
        point = CGPointMake(pX, pY);
        unichar c = [self.CodeStr characterAtIndex:i];
        NSString *textC = [NSString stringWithFormat:@\"%C\", c];
        [textC drawAtPoint:point withAttributes:@{NSFontAttributeName:[UIFont systemFontOfSize:20]}];
    }
    
    //干扰线
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetLineWidth(context, 1.0);
    for(int cout = 0; cout < 10; cout++)
    {
        CGContextSetStrokeColorWithColor(context, [ARC_COLOR CGColor]);
        pX = arc4random() % (int)rect.size.width;
        pY = arc4random() % (int)rect.size.height;
        CGContextMoveToPoint(context, pX, pY);
        pX = arc4random() % (int)rect.size.width;
        pY = arc4random() % (int)rect.size.height;
        CGContextAddLineToPoint(context, pX, pY);
        CGContextStrokePath(context);
    }
}


@end

最终效果

项目代码地址

https://github.com/yushengchu/VerCodeView