验证码的功能一般是防止使用程序恶意注册、暴力破解或批量发帖而设置的。所谓验证码，就是将一串随机产生的数字或符号，生成一幅图片，图片里加上一些干扰象素（防止OCR），图片验证码相信大家都见到过，这篇文章用示例代码给大家介绍iOS绘制图片生成随机验证码的方法。
先来看看效果图
实现方法
.h文件
@property (nonatomic, retain) NSArray *changeArray; @property (nonatomic, retain) NSMutableString *changeString; @property (nonatomic, retain) UILabel *codeLabel; -(void)changeCode; @end
.m文件
@synthesize changeArray = _changeArray; @synthesize changeString = _changeString; @synthesize codeLabel = _codeLabel; - (id)initWithFrame:(CGRect)frame { self = [super initWithFrame:frame]; if (self) { // Initialization code float red = arc4random() % 100 / 100.0; float green = arc4random() % 100 / 100.0; float blue = arc4random() % 100 / 100.0; UIColor *color = [UIColor colorWithRed:red green:green blue:blue alpha:0.2]; self.backgroundColor = color; [self change]; } return self; } -(void)changeCode { [self change]; [self setNeedsDisplay]; } - (void)change { 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",nil]; NSMutableString *getStr = [[NSMutableString alloc] initWithCapacity:5]; self.changeString = [[NSMutableString alloc] initWithCapacity:6]; for(NSInteger i = 0; i <4; i++) { NSInteger index = arc4random() % ([self.changeArray count] - 1); getStr = [self.changeArray objectAtIndex:index]; self.changeString = (NSMutableString *)[self.changeString stringByAppendingString:getStr]; } } - (void)drawRect:(CGRect)rect { [super drawRect:rect]; float red = arc4random() % 100 / 100.0; float green = arc4random() % 100 / 100.0; float blue = arc4random() % 100 / 100.0; UIColor *color = [UIColor colorWithRed:red green:green blue:blue alpha:0.5]; [self setBackgroundColor:color]; 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; float pX, pY; for (int i = 0; i VIewController中调用
_codeView = [[CodeView alloc] initWithFrame:CGRectMake(15+(SCREEN_WIDTH-30)/3*2, 75, (SCREEN_WIDTH-30)/3, 39)]; //手势 UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapClick:)]; [_codeView addGestureRecognizer:tap]; [self.view addSubview: _codeView];
手势事件
- (void)tapClick:(UITapGestureRecognizer*)tap { [_codeView changeCode]; }总结
以上就是利用iOS绘制图片随机验证码的全部内容，希望本文的内容对各位iOS开发者们能有所帮助，如果有疑问大家可以留言交流。
以上就是利用iOS绘制图片生成随机验证码示例代码的详细内容，更多请关注0133技术站其它相关文章！
