首页 / 移动开发 / IOS / iOS本地动态生成验证码的方法

• 导入CoreGraphics.framework

• 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@endAuthcodeView.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CGContextRefCGContextRef 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];}}