iOS开发入门：iOS生成本地验证码-职坐标

iOS开发入门：iOS生成本地验证码

安安 2017-11-21 来源：网络阅读 837 评论 0

摘要：本篇IOS开发入门教程将为大家讲解IOS编程的知识点，看完这篇文章会让你对IOS编程的知识点有更加清晰的理解和运用。

本篇IOS开发入门教程将为大家讲解IOS编程的知识点，看完这篇文章会让你对IOS编程的知识点有更加清晰的理解和运用。

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。

iOS开发入门：iOS生成本地验证码

导入CoreGraphics.framework

iOS开发入门：iOS生成本地验证码

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

@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 ()

{

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;