本文实例为大家分享了ios生成图片数字字母验证的具体代码，供大家参考，具体内容如下
直接上代码，注释很详细
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#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 krandomcolor [uicolor graycolor];#define klinecount 6#define klinewidth 1.0#define kcharcount 4#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; // [uicolor graycolor] //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",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]; }}#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:20.0]}]; 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 |
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持服务器之家。
原文链接：https://blog.csdn.net/bobbob32/article/details/77527553
