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[操作系统]IOS 生成本地验证码


  在应用程序注册、登陆或者有关支付确认的界面,经常会用到验证码,验证码有的是通过手机发送获取的,有的是在本地点击获取的,通过手机发送获取的动态验证码可以使用第三方类库实现,本地点击获取的是在本地自己绘制的,下面我们来详细讲解一下本地生成动态验证码的过程。

 

<一>导入CoreGraphics.framework

 

<二>验证码封装了一个UIView,在使用的时候直接把这个View加到界面上使用

  CaptchaView.h

#import <UIKit/UIKit.h>@interface CaptchaView : UIView@property (nonatomic, retain) NSArray *changeArray; //字符素材数组@property (nonatomic, retain) NSMutableString *changeString; //验证码的字符串@end

  CaptchaView.m

#import "CaptchaView.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 CaptchaView@synthesize changeString,changeArray;- (instancetype)initWithFrame:(CGRect)frame{  if (self = [super initWithFrame:frame]) {        self.layer.cornerRadius = 5.0; //设置layer圆角半径    self.layer.masksToBounds = YES; //隐藏边界    self.backgroundColor = kRandomColor;        //显示一个随机验证码    [self changeCaptcha];  }    return self;}#pragma mark 更换验证码,得到更换的验证码的字符串-(void)changeCaptcha{//<一>从字符数组中随机抽取相应数量的字符,组成验证码字符串  //数组中存放的是全部可选的字符,可以是字母,也可以是中文  self.changeArray = [[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",@"杰",@"瑞",@"教",@"育",nil];    //如果能确定最大需要的容量,使用initWithCapacity:来设置,好处是当元素个数不超过容量时,添加元素不需要重新分配内存  NSMutableString *getStr = [[NSMutableString alloc] initWithCapacity:kCharCount];  self.changeString = [[NSMutableString alloc] initWithCapacity:kCharCount];    //随机从数组中选取需要个数的字符,然后拼接为一个字符串  for(int i = 0; i < kCharCount; i++)  {    NSInteger index = arc4random() % ([self.changeArray count] - 1);    getStr = [self.changeArray objectAtIndex:index];        self.changeString = (NSMutableString *)[self.changeString stringByAppendingString:getStr];  }  //<2>从网络获取字符串,然后把得到的字符串在本地绘制出来(网络获取步骤在这省略)//  self.changeString = [NSMutableString stringWithString:@"杰瑞教育"];}#pragma mark 点击view时调用,因为当前类自身就是UIView,点击更换验证码可以直接写到这个方法中,不用再额外添加手势-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{  //点击界面,切换验证码  [self changeCaptcha];    //setNeedsDisplay调用drawRect方法来实现view的绘制  [self setNeedsDisplay];}#pragma mark 绘制界面(1.UIView初始化后自动调用; 2.调用setNeedsDisplay方法时会自动调用)- (void)drawRect:(CGRect)rect {  // 重写父类方法,首先要调用父类的方法  [super drawRect:rect];  //设置随机背景颜色  self.backgroundColor = kRandomColor;    //获得要显示验证码字符串,根据长度,计算每个字符显示的大概位置  NSString *text = [NSString stringWithFormat:@"%@",self.changeString];  CGSize cSize = [@"S" 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();  //设置画线宽度  CGContextSetLineWidth(context, kLineWidth);    //绘制干扰的彩色直线  for(int i = 0; i < kLineCount; i++)  {    //设置线的随机颜色    UIColor *color = kRandomColor;    CGContextSetStrokeColorWithColor(context, [color CGColor]);    //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

<三>在界面上添加验证码

   ViewController.m

#import "ViewController.h"#import "CaptchaView.h"@interface ViewController ()<UITextFieldDelegate,UIAlertViewDelegate>{  CaptchaView *_captchaView;  UITextField *_input;}@end@implementation ViewController- (void)viewDidLoad {  [super viewDidLoad];    //显示验证码界面  _captchaView = [[CaptchaView alloc] initWithFrame:CGRectMake(20, 40, 150, 40)];  [self.view addSubview:_captchaView];    //提示文字  UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(190, 40, 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(20, 100, 150, 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 输入框协议中方法,点击return按钮- (BOOL)textFieldShouldReturn:(UITextField *)textField{  //判断输入的是否为验证图片显示的验证码  if ([_input.text isEqualToString:_captchaView.changeString]) {    //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,验证码和输入框晃动    CAKeyframeAnimation *anim = [CAKeyframeAnimation animationWithKeyPath:@"transform.translation.x"];    anim.repeatCount = 1;    anim.values = @[@-20, @20, @-20];    [_captchaView.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];  }}@end

 

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作者:杰瑞教育
出处:http://www.cnblogs.com/jerehedu/ 
本文版权归烟台杰瑞教育科技有限公司和博客园共有,欢迎转载,但未经作者同意必须保留此段声明,且在文章页面明显位置给出原文连接,否则保留追究法律责任的权利。