.NET Core 2.0如何生成图片验证码完整实例
程序员文章站
2022-03-09 21:44:51
前言
图片验证码在我们日常开发中是必不可少会遇见的一个功能，最近工作中就遇到了这个需求，所以下面将实现的方法分享给大家，话不多说了，来一起看看详细的介绍吧。
.net...
前言
图片验证码在我们日常开发中是必不可少会遇见的一个功能，最近工作中就遇到了这个需求，所以下面将实现的方法分享给大家，话不多说了，来一起看看详细的介绍吧。
.net core 2.0生成图片验证码
nuget包引入：zkweb.system.drawing，如下所示：
代码实例如下：verifycodehelper
using system;
using system.drawingcore;
using system.drawingcore.drawing2d;
using system.drawingcore.imaging;
using system.io;
namespace common.helper
{
public sealed class verifycodehelper
{
#region 单例模式
//创建私有化静态obj锁
private static readonly object _objlock = new object();
//创建私有静态字段，接收类的实例化对象
private static verifycodehelper _verifycodehelper = null;
//构造函数私有化
private verifycodehelper() { }
//创建单利对象资源并返回
public static verifycodehelper getsingleobj()
{
if (_verifycodehelper == null)
{
lock (_objlock)
{
if (_verifycodehelper == null)
_verifycodehelper = new verifycodehelper();
}
}
return _verifycodehelper;
}
#endregion
#region 生产验证码
public enum verifycodetype { numberverifycode, abcverifycode, mixverifycode };
/// <summary>
/// 1.数字验证码
/// </summary>
/// <param name="length"></param>
/// <returns></returns>
private string createnumberverifycode(int length)
{
int[] randmembers = new int[length];
int[] validatenums = new int[length];
string validatenumberstr = "";
//生成起始序列值
int seekseek = unchecked((int)datetime.now.ticks);
random seekrand = new random(seekseek);
int beginseek = seekrand.next(0, int32.maxvalue - length * 10000);
int[] seeks = new int[length];
for (int i = 0; i < length; i++)
{
beginseek += 10000;
seeks[i] = beginseek;
}
//生成随机数字
for (int i = 0; i < length; i++)
{
random rand = new random(seeks[i]);
int pownum = 1 * (int)math.pow(10, length);
randmembers[i] = rand.next(pownum, int32.maxvalue);
}
//抽取随机数字
for (int i = 0; i < length; i++)
{
string numstr = randmembers[i].tostring();
int numlength = numstr.length;
random rand = new random();
int numposition = rand.next(0, numlength - 1);
validatenums[i] = int32.parse(numstr.substring(numposition, 1));
}
//生成验证码
for (int i = 0; i < length; i++)
{
validatenumberstr += validatenums[i].tostring();
}
return validatenumberstr;
}
/// <summary>
/// 2.字母验证码
/// </summary>
/// <param name="length">字符长度</param>
/// <returns>验证码字符</returns>
private string createabcverifycode(int length)
{
char[] verification = new char[length];
char[] dictionary = { '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'
};
random random = new random();
for (int i = 0; i < length; i++)
{
verification[i] = dictionary[random.next(dictionary.length - 1)];
}
return new string(verification);
}
/// <summary>
/// 3.混合验证码
/// </summary>
/// <param name="length">字符长度</param>
/// <returns>验证码字符</returns>
private string createmixverifycode(int length)
{
char[] verification = new char[length];
char[] dictionary = { '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',
'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'
};
random random = new random();
for (int i = 0; i < length; i++)
{
verification[i] = dictionary[random.next(dictionary.length - 1)];
}
return new string(verification);
}
/// <summary>
/// 产生验证码（随机产生4-6位）
/// </summary>
/// <param name="type">验证码类型：数字，字符，符合</param>
/// <returns></returns>
public string createverifycode(verifycodetype type)
{
string verifycode = string.empty;
random random = new random();
int length = random.next(4, 6);
switch (type)
{
case verifycodetype.numberverifycode:
verifycode = getsingleobj().createnumberverifycode(length);
break;
case verifycodetype.abcverifycode:
verifycode = getsingleobj().createabcverifycode(length);
break;
case verifycodetype.mixverifycode:
verifycode = getsingleobj().createmixverifycode(length);
break;
}
return verifycode;
}
#endregion
#region 验证码图片
/// <summary>
/// 验证码图片 => bitmap
/// </summary>
/// <param name="verifycode">验证码</param>
/// <param name="width">宽</param>
/// <param name="height">高</param>
/// <returns>bitmap</returns>
public bitmap createbitmapbyimgverifycode(string verifycode, int width, int height)
{
font font = new font("arial", 14, (fontstyle.bold | fontstyle.italic));
brush brush;
bitmap bitmap = new bitmap(width, height);
graphics g = graphics.fromimage(bitmap);
sizef totalsizef = g.measurestring(verifycode, font);
sizef curcharsizef;
pointf startpointf = new pointf(0, (height - totalsizef.height) / 2);
random random = new random(); //随机数产生器
g.clear(color.white); //清空图片背景色
for (int i = 0; i < verifycode.length; i++)
{
brush = new lineargradientbrush(new point(0, 0), new point(1, 1), color.fromargb(random.next(255), random.next(255), random.next(255)), color.fromargb(random.next(255), random.next(255), random.next(255)));
g.drawstring(verifycode[i].tostring(), font, brush, startpointf);
curcharsizef = g.measurestring(verifycode[i].tostring(), font);
startpointf.x += curcharsizef.width;
}
//画图片的干扰线
for (int i = 0; i < 10; i++)
{
int x1 = random.next(bitmap.width);
int x2 = random.next(bitmap.width);
int y1 = random.next(bitmap.height);
int y2 = random.next(bitmap.height);
g.drawline(new pen(color.silver), x1, y1, x2, y2);
}
//画图片的前景干扰点
for (int i = 0; i < 100; i++)
{
int x = random.next(bitmap.width);
int y = random.next(bitmap.height);
bitmap.setpixel(x, y, color.fromargb(random.next()));
}
g.drawrectangle(new pen(color.silver), 0, 0, bitmap.width - 1, bitmap.height - 1); //画图片的边框线
g.dispose();
return bitmap;
}
/// <summary>
/// 验证码图片 => byte[]
/// </summary>
/// <param name="verifycode">验证码</param>
/// <param name="width">宽</param>
/// <param name="height">高</param>
/// <returns>byte[]</returns>
public byte[] createbytebyimgverifycode(string verifycode, int width, int height)
{
font font = new font("arial", 14, (fontstyle.bold | fontstyle.italic));
brush brush;
bitmap bitmap = new bitmap(width, height);
graphics g = graphics.fromimage(bitmap);
sizef totalsizef = g.measurestring(verifycode, font);
sizef curcharsizef;
pointf startpointf = new pointf(0, (height - totalsizef.height) / 2);
random random = new random(); //随机数产生器
g.clear(color.white); //清空图片背景色
for (int i = 0; i < verifycode.length; i++)
{
brush = new lineargradientbrush(new point(0, 0), new point(1, 1), color.fromargb(random.next(255), random.next(255), random.next(255)), color.fromargb(random.next(255), random.next(255), random.next(255)));
g.drawstring(verifycode[i].tostring(), font, brush, startpointf);
curcharsizef = g.measurestring(verifycode[i].tostring(), font);
startpointf.x += curcharsizef.width;
}
//画图片的干扰线
for (int i = 0; i < 10; i++)
{
int x1 = random.next(bitmap.width);
int x2 = random.next(bitmap.width);
int y1 = random.next(bitmap.height);
int y2 = random.next(bitmap.height);
g.drawline(new pen(color.silver), x1, y1, x2, y2);
}
//画图片的前景干扰点
for (int i = 0; i < 100; i++)
{
int x = random.next(bitmap.width);
int y = random.next(bitmap.height);
bitmap.setpixel(x, y, color.fromargb(random.next()));
}
g.drawrectangle(new pen(color.silver), 0, 0, bitmap.width - 1, bitmap.height - 1); //画图片的边框线
g.dispose();
//保存图片数据
memorystream stream = new memorystream();
bitmap.save(stream, imageformat.jpeg);
//输出图片流
return stream.toarray();
}
#endregion
}
}
新建控制器：verifycodecontroller，
using system.drawingcore.imaging;
using system.io;
using common.helper;
using microsoft.aspnetcore.mvc;
namespace webapplicationapi.controllers
{
public class verifycodecontroller : controller
{
public iactionresult index()
{
return view();
}
/// <summary>
/// 数字验证码
/// </summary>
/// <returns></returns>
public filecontentresult numberverifycode()
{
string code = verifycodehelper.getsingleobj().createverifycode(verifycodehelper.verifycodetype.numberverifycode);
byte[] codeimage = verifycodehelper.getsingleobj().createbytebyimgverifycode(code, 100, 40);
return file(codeimage, @"image/jpeg");
}
/// <summary>
/// 字母验证码
/// </summary>
/// <returns></returns>
public filecontentresult abcverifycode()
{
string code = verifycodehelper.getsingleobj().createverifycode(verifycodehelper.verifycodetype.abcverifycode);
var bitmap = verifycodehelper.getsingleobj().createbitmapbyimgverifycode(code, 100, 40);
memorystream stream = new memorystream();
bitmap.save(stream, imageformat.png);
return file(stream.toarray(), "image/png");
}
/// <summary>
/// 混合验证码
/// </summary>
/// <returns></returns>
public filecontentresult mixverifycode()
{
string code = verifycodehelper.getsingleobj().createverifycode(verifycodehelper.verifycodetype.mixverifycode);
var bitmap = verifycodehelper.getsingleobj().createbitmapbyimgverifycode(code, 100, 40);
memorystream stream = new memorystream();
bitmap.save(stream, imageformat.gif);
return file(stream.toarray(), "image/gif");
}
}
}
添加页面index.cshtml，如下代码：
@{
layout = null;
}
<!doctype html>
<html>
<head>
<meta name="viewport" content="width=device-width" />
<title>index</title>
</head>
<body>
<figure>
<h3>图片验证码</h3>
<fieldset>
<legend>数字验证码</legend>
<img id="nubimg" title="数字验证码" src="/verifycode/numberverifycode?random=" alt="vcode" onclick="refresh()" style="cursor:pointer;" />
</fieldset>
<fieldset>
<legend>数字验证码</legend>
<img id="abcimg" title="字母验证码" src="/verifycode/abcverifycode" alt="vcode" onclick="this.src=this.src+'?'" style="cursor:pointer;" />
</fieldset>
<fieldset>
<legend>混合验证码</legend>
<img id="miximg" title="数字字母混合验证码" src="/verifycode/mixverifycode" alt="vcode" onclick="this.src=this.src+'?'" style="cursor:pointer;" />
</fieldset>
</figure>
<script type="text/javascript">
function refresh() {
var id = document.getelementbyid("nubimg");
var str = "/verifycode/numberverifycode?random=" + math.random();
id.setattribute("src", str);
}
</script>
</body>
</html>
生成验证码如下所示：
总结
以上就是这篇文章的全部内容了，希望本文的内容对大家的学习或者工作具有一定的参考学习价值，如果有疑问大家可以留言交流，谢谢大家对的支持。