利用ios绘制图片生成随机验证码示例代码（利用ios绘制图片生成随机验证码示例代码）

先来看看效果图

实现方法

.h文件

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@property (nonatomic, retain) nsarray *changearray; @property (nonatomic, retain) nsmutablestring *changestring; @property (nonatomic, retain) uilabel *codelabel; -(void)changecode; @end

.m文件

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@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 < 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:[uifont systemfontofsize:20]}]; } cgcontextref context = uigraphicsgetcurrentcontext(); cgcontextsetlinewidth(context, 1.0); for(int cout = 0; cout < 10; cout++) { red = arc4random() % 100 / 100.0; green = arc4random() % 100 / 100.0; blue = arc4random() % 100 / 100.0; color = [uicolor colorwithred:red green:green blue:blue alpha:0.2]; cgcontextsetstrokecolorwithcolor(context, [color cgcolor]); px = arc4random() % (int)rect.size.width; py = arc4random() % (int)rect.size.height; cgcontextmovetopoint(context, px, py); px = arc4random() % (int)rect.size.width; py = arc4random() % (int)rect.size.height; cgcontextaddlinetopoint(context, px, py); cgcontextstrokepath(context); } } @end

viewcontroller中调用

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_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

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- (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。