AuthcodeView.h#import <UIKit/UIKit.h>@interface AuthcodeView : UIView@property (strong, nonatomic) NSArray *dataArray;//字符素材數組@property (strong, nonatomic) NSMutableString *authCodeStr;//驗證碼字符串@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];//獲得隨機驗證碼  }  return self;}#pragma mark 獲得隨機驗證碼- (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];  //隨機從數組中選取需要個數的字符串，拼接為驗證碼字符串  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 點擊界面切換驗證碼- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{  [self getAuthcode];  //setNeedsDisplay調用drawRect方法來實現view的繪制  [self setNeedsDisplay];}- (void)drawRect:(CGRect)rect{  [super drawRect:rect];  //設置隨機背景顏色  self.backgroundColor = kRandomColor;  //根據要顯示的驗證碼字符串，根據長度，計算每個字符串顯示的位置  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;  //依次繪制每一個字符,可以設置顯示的每個字符的字體大小、顏色、樣式等  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}];  }   //調用drawRect：之前，系統會向棧中壓入一個CGContextRef，調用UIGraphicsGetCurrentContext()會取棧頂的CGContextRef  CGContextRef context = UIGraphicsGetCurrentContext();  //設置線條寬度  CGContextSetLineWidth(context, kLineWidth);  //繪制干擾線  for (int i = 0; i < kLineCount; i++)  {    UIColor *color = kRandomColor;    CGContextSetStrokeColorWithColor(context, color.CGColor);//設置線條填充色    //設置線的起點    pX = arc4random() % (int)rect.size.width;    pY = arc4random() % (int)rect.size.height;    CGContextMoveToPoint(context, pX, pY);    //設置線終點    pX = arc4random() % (int)rect.size.width;    pY = arc4random() % (int)rect.size.height;    CGContextAddLineToPoint(context, pX, pY);    //畫線    CGContextStrokePath(context);  }}@end

@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];  //顯示驗證碼界面  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 = @"點擊圖片換驗證碼";  label.font = [UIFont systemFontOfSize:12];  label.textColor = [UIColor grayColor];  [self.view addSubview:label];  //添加輸入框  _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 = @"請輸入驗證碼!";  _input.clearButtonMode = UITextFieldViewModeWhileEditing;  _input.backgroundColor = [UIColor clearColor];  _input.textAlignment = NSTextAlignmentCenter;  _input.returnKeyType = UIReturnKeyDone;  _input.delegate = self;  [self.view addSubview:_input];}#pragma mark 輸入框代理，點擊return 按鈕- (BOOL)textFieldShouldReturn:(UITextField *)textField{  //判斷輸入的是否為驗證圖片中顯示的驗證碼  if ([_input.text isEqualToString:authCodeView.authCodeStr])  {    //正確彈出警告款提示正確    UIAlertView *alview = [[UIAlertView alloc] initWithTitle:@"恭喜您 ^o^" message:@"驗證成功" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];    [alview show];  }  else  {    //驗證不匹配，驗證碼和輸入框抖動    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{  //清空輸入框內容，收回鍵盤  if (buttonIndex==0)  {    _input.text = @"";    [_input resignFirstResponder];  }}