iOS本地动态验证码生成-b

用于ios本地动态生成验证码，效果如下：

demo.gif

• 导入CoreGraphics.framework
  用于绘制图形

• 封装UIView，便捷使用，代码如下：

AuthcodeView.h

#import <UIKit/UIKit.h>
@interface AuthcodeView : UIView
@property (strong, nonatomic) NSArray *dataArray;//字符素材数组
@property (strong, nonatomic) NSMutableString *authCodeStr;//验证码字符串@end

AuthcodeView.m

#import "AuthcodeView.h"
#define kRandomColor  [UIColor colorWithRed:arc4random() % 256 / 256.0 green:arc4random() % 256 / 256.0 blue:arc4random() % 256 / 256.0 alpha:1.0];
#define kLineCount 6
#define kLineWidth 1.0
#define kCharCount 6
#define kFontSize [UIFont systemFontOfSize:arc4random() % 5 + 15]
@implementation AuthcodeView
/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect {    
    // Drawing code
}
*/
- (instancetype)initWithFrame:(CGRect)frame {    
    self = [super initWithFrame:frame];    
    if (self)     {        
        self.layer.cornerRadius = 5.0f;        
        self.layer.masksToBounds = YES;        
        self.backgroundColor = kRandomColor;          
        [self getAuthcode];//获得随机验证码    
    }    
    return self;
}
#pragma mark 获得随机验证码
- (void)getAuthcode {    
    //字符串素材    
    _dataArray = [[NSArray alloc] initWithObjects:@"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",nil];      
    _authCodeStr = [[NSMutableString alloc] initWithCapacity:kCharCount];    //随机从数组中选取需要个数的字符串，拼接为验证码字符串    
    for (int i = 0; i < kCharCount; i++)     {        
        NSInteger index = arc4random() % (_dataArray.count-1);        NSString *tempStr = [_dataArray objectAtIndex:index];        
        _authCodeStr = (NSMutableString *)[_authCodeStr stringByAppendingString:tempStr];    
    }
}
#pragma mark 点击界面切换验证码

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {    
    [self getAuthcode];    //setNeedsDisplay调用drawRect方法来实现view的绘制    
    [self setNeedsDisplay];
}  
- (void)drawRect:(CGRect)rect {    
    [super drawRect:rect];    //设置随机背景颜色    
    self.backgroundColor = kRandomColor;    //根据要显示的验证码字符串，根据长度，计算每个字符串显示的位置    
    NSString *text = [NSString stringWithFormat:@"%@",_authCodeStr];    CGSize cSize = [@"A" sizeWithAttributes:@{NSFontAttributeName:[UIFont systemFontOfSize:20]}];    int width = rect.size.width/text.length - cSize.width;    int height = rect.size.height - cSize.height;    CGPoint point;    //依次绘制每一个字符,可以设置显示的每个字符的字体大小、颜色、样式等    
    float pX,pY;    
    for ( int i = 0; i<text.length; i++)     {        
        pX = arc4random() % width + rect.size.width/text.length * i;        
        pY = arc4random() % height;        
        point = CGPointMake(pX, pY);        
        unichar c = [text characterAtIndex:i];        
        NSString *textC = [NSString stringWithFormat:@"%C", c];          
        [textC drawAtPoint:point withAttributes:@{NSFontAttributeName:kFontSize}];    
    }     //调用drawRect：之前，系统会向栈中压入一个CGContextRef，调用UIGraphicsGetCurrentContext()会取栈顶的CGContextRef    
    CGContextRef context = UIGraphicsGetCurrentContext();    //设置线条宽度    
    CGContextSetLineWidth(context, kLineWidth);    //绘制干扰线    
    for (int i = 0; i < kLineCount; i++)     {        
        UIColor *color = kRandomColor;        
        CGContextSetStrokeColorWithColor(context, color.CGColor);//设置线条填充色          
        //设置线的起点        
        pX = arc4random() % (int)rect.size.width;        
        pY = arc4random() % (int)rect.size.height;        
        CGContextMoveToPoint(context, pX, pY);        //设置线终点        
        pX = arc4random() % (int)rect.size.width;        
        pY = arc4random() % (int)rect.size.height;        
        CGContextAddLineToPoint(context, pX, pY);        //画线        
        CGContextStrokePath(context);    
     }
}
@end

• 界面添加验证码

@interface AuthCodeViewController ()<UITextFieldDelegate, UIAlertViewDelegate>
{    
    AuthcodeView *authCodeView;    
    UITextField *_input;
}
@end
@implementation AuthCodeViewController
- (void)viewDidLoad {    
    [super viewDidLoad];    // Do any additional setup after loading the view.      
    self.view.backgroundColor = [UIColor whiteColor];    //显示验证码界面    
    authCodeView = [[AuthcodeView alloc] initWithFrame:CGRectMake(30, 100, self.view.frame.size.width-60, 40)];    
    [self.view addSubview:authCodeView];    //提示文字    
    UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(50, 160, self.view.frame.size.width-100, 40)];    
    label.text = @"点击图片换验证码";    
    label.font = [UIFont systemFontOfSize:12];    
    label.textColor = [UIColor grayColor];    
    [self.view addSubview:label];    //添加输入框    
    _input = [[UITextField alloc] initWithFrame:CGRectMake(30, 220, self.view.frame.size.width-60, 40)];    
    _input.layer.borderColor = [UIColor lightGrayColor].CGColor;    
    _input.layer.borderWidth = 2.0;    
    _input.layer.cornerRadius = 5.0;    
    _input.font = [UIFont systemFontOfSize:21];    
    _input.placeholder = @"请输入验证码!";    
    _input.clearButtonMode = UITextFieldViewModeWhileEditing;    
    _input.backgroundColor = [UIColor clearColor];    
    _input.textAlignment = NSTextAlignmentCenter;    
    _input.returnKeyType = UIReturnKeyDone;    
    _input.delegate = self;    
    [self.view addSubview:_input];
}
#pragma mark 输入框代理，点击return 按钮

- (BOOL)textFieldShouldReturn:(UITextField *)textField {    
    //判断输入的是否为验证图片中显示的验证码    
    if ([_input.text isEqualToString:authCodeView.authCodeStr])     {        
        //正确弹出警告款提示正确        
        UIAlertView *alview = [[UIAlertView alloc] initWithTitle:@"恭喜您 ^o^" message:@"验证成功" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];        
        [alview show];    
    }    else     {        //验证不匹配，验证码和输入框抖动        
        CAKeyframeAnimation *anim = [CAKeyframeAnimation animationWithKeyPath:@"transform.translation.x"];        
        anim.repeatCount = 1;        
        anim.values = @[@-20,@20,@-20];//        [authCodeView.layer addAnimation:anim forKey:nil];        
        [_input.layer addAnimation:anim forKey:nil];    
    }    
    return YES;
}
#pragma mark 警告框中方法
-(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {    
    //清空输入框内容，收回键盘    
    if (buttonIndex==0)     {        
        _input.text = @"";        
        [_input resignFirstResponder];    
    }
}