asp.net web api实现图片点击式图片验证码

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现在验证码的形式越来越丰富，今天要实现的是在点击图片中的文字来进行校验的验证码，如图

这种验证码验证是验证鼠标是否选中了图片中文字的位置，以及选择的顺序，产生验证码的时候可以提供一组底图，然后随机获取一张图片，随机选取几个字，然后把文字的顺序打乱，分别随机放到图片的一个位置上,然后记录文字的位置和顺序，验证的时候验证一下文字的位置和顺序即可

验证码图片的类

/// <summary>
/// 二维码图片
/// </summary>
public class VerCodePic
{
/// <summary>
/// 图片链接
/// </summary>
public string PicURL { get; set; }
/// <summary>
/// 第一个字位置
/// </summary>
public FontPoint Font1 { get; set; }
/// <summary>
/// 第二个字位置
/// </summary>
public FontPoint Font2 { get; set; }
/// <summary>
/// 第三个字位置
/// </summary>
public FontPoint Font3 { get; set; }
/// <summary>
/// 第四个字位置
/// </summary>
public FontPoint Font4 { get; set; }
}
/// <summary>
/// 文字位置
/// </summary>
public class FontPoint
{
public int X { get; set; }
public int Y { get; set; }
}

生成验证码图片验证码的方法，在这个方法中指定了生成的验证码图片中字体大小为20个像素，因为验证码底图的大小是固定的，所以就把验证码底图按照字体的大小分成了若干个网格位置，指定一个文字在图片中的位置时只需要随机获取其中一个网格即可，如果这个网格中没有指定过文字，那就把文字放到这个网格中。

提前设定网格的方法

private static ArrayList _FontPoint;
public static ArrayList FontPoint
{
get
{
if (_FontPoint==null)
{
_FontPoint = new ArrayList(); for (int x=;x<;x++)
{
for (int y=;y<;y++)
{
_FontPoint.Add(new Models.FontPoint() { X = x * , Y = y * });
}
}
}
return _FontPoint;
}
}

我选定的验证码底图为280*100的，所以按照上边的方法将图片分成了若干个网格，在下边设定一个文字位置的时候随机选取其中一个位置，而且给每个字都设定了不一样的颜色

/// <summary>
/// 根据文字和图片获取验证码图片
/// </summary>
/// <param name="content"></param>
/// <param name="picFileName"></param>
/// <returns></returns>
public static VerCodePic GetVerCodePic(string content,string picFileName,int fontSize=)
{
ClassLoger.Info("FileHelper.GetVerCodePic","开始生成二维码");
Bitmap bmp = new Bitmap(picFileName);
List<int> hlist = new List<int>();
VerCodePic codepic = new VerCodePic();
int i = Utils.GetRandom(, SystemSet.FontPoint.Count - );
codepic.Font1 = SystemSet.FontPoint[i] as FontPoint;
hlist.Add(i); A: int i2 = Utils.GetRandom(, SystemSet.FontPoint.Count - );
if (hlist.Contains(i2))
goto A;
codepic.Font2 = SystemSet.FontPoint[i2] as FontPoint;
hlist.Add(i2); B: int i3 = Utils.GetRandom(, SystemSet.FontPoint.Count - );
if (hlist.Contains(i3))
goto B;
hlist.Add(i3);
codepic.Font3 = SystemSet.FontPoint[i3] as FontPoint; C: int i4 = Utils.GetRandom(, SystemSet.FontPoint.Count - );
if (hlist.Contains(i4))
goto C;
hlist.Add(i4);
codepic.Font4 = SystemSet.FontPoint[i4] as FontPoint;string fileName = (content + "-" + picFileName+"-"+i+"|"+i2+"|"+i3+"|"+i4).MD5()+Path.GetExtension(picFileName);
string dir = Path.Combine(SystemSet.ResourcesPath, SystemSet.VerCodePicPath);
string filePath = Path.Combine(dir, fileName);
if (File.Exists(filePath))
{
codepic.PicURL = string.Format("{0}/{1}/{2}", SystemSet.WebResourcesSite, SystemSet.VerCodePicPath, fileName);
return codepic;
}
if (!Directory.Exists(dir))
{
Directory.CreateDirectory(dir);
} Graphics g = Graphics.FromImage(bmp);
Font font = new Font("微软雅黑", fontSize, GraphicsUnit.Pixel);
SolidBrush sbrush = new SolidBrush(Color.Black);
SolidBrush sbrush1 = new SolidBrush(Color.Peru);
SolidBrush sbrush2 = new SolidBrush(Color.YellowGreen);
SolidBrush sbrush3 = new SolidBrush(Color.SkyBlue);
List<char> fontlist = content.ToList();
ClassLoger.Info("FileHelper.GetVerCodePic", fontlist.Count.ToString());
g.DrawString(fontlist[].TryToString(), font, sbrush, new PointF(codepic.Font1.X, codepic.Font1.Y));
g.DrawString(fontlist[].TryToString(), font, sbrush1, new PointF(codepic.Font2.X, codepic.Font2.Y));
g.DrawString(fontlist[].TryToString(), font, sbrush2, new PointF(codepic.Font3.X, codepic.Font3.Y));
g.DrawString(fontlist[].TryToString(), font, sbrush3, new PointF(codepic.Font4.X, codepic.Font4.Y)); bmp.Save(filePath, ImageFormat.Jpeg);
codepic.PicURL = string.Format("{0}/{1}/{2}",SystemSet.WebResourcesSite, SystemSet.VerCodePicPath, fileName);
return codepic;
}

获取图片验证码的api接口，在这个接口中从成语库中随机选取了一个成语，然后随机选取了一个图片，然后调用生成图片验证码的方法，生成了图片验证码，并且把验证码对应的信息缓存在redis中，设定缓存时间，将redis的key作为一个临时令牌随同验证码返回

/// <summary>
/// 获取验证码，有效时间10分钟
/// </summary>
/// <returns></returns>
[HttpGet]
[Route("vercode")]
public JsonResult<VerCodePicViewModel> VerCodePic()
{
JsonResult<VerCodePicViewModel> result = new JsonResult<VerCodePicViewModel>();
result.code = ;
result.msg = "OK";
try
{
ClassLoger.Info("VerCodePic","开始获取成语");
cy_dictBll cybll = new cy_dictBll();
IList<cy_dict> cylist = cybll.GetAllcy_dict();
ClassLoger.Info("VerCodePic", cylist.Count.ToString());
int i = Utils.GetRandom(, cylist.Count-);
ClassLoger.Info("VerCodePic",i.ToString());
cy_dict cy = cylist[i];
ClassLoger.Info("VerCodePic成语：",cy.chengyu);
VerCodePicViewModel vcvm = new VerCodePicViewModel(); string sourcePic = FileHelper.GetVerCodePicResource();
if (sourcePic.IsNull() || !File.Exists(sourcePic))
{
sourcePic = @"E:\WebResources\images\VerCodePicSource\1.jpg";
}
ClassLoger.Info("VerCodePic图片",sourcePic);
VerCodePic codepic = FileHelper.GetVerCodePic(cy.chengyu, sourcePic);
vcvm.content = cy.chengyu;
vcvm.MainPic = codepic.PicURL;
result.Result = vcvm; string key = cookieKey();
RedisBase.Item_Set(key, codepic);
RedisBase.ExpireEntryAt(key,DateTime.Now.AddMinutes());
result.ResultMsg = key;
} catch (Exception ex)
{
ClassLoger.Error("AccountController.VerCodePic",ex);
result.code = -;
result.msg = "AccountController.VerCodePic发生异常:"+ex.Message;
}
return result;
}

效果如图：

图片验证码校验接口参数结构

public class CheckPicCodeViewModel
{
/// <summary>
/// 客户端令牌
/// </summary>
public string token { get; set; } public double x1 { get; set; } public double x2 { get; set; } public double x3 { get; set; } public double x4 { get; set; } public double y1 { get; set; } public double y2 { get; set; } public double y3 { get; set; } public double y4 { get; set; }
}

验证码校验接口

/// <summary>
/// 校验图片验证码是否正确
/// </summary>
/// <param name="piccode"></param>
/// <returns></returns>
[HttpPost]
[Route("checkpiccode")]
public async Task<IHttpActionResult> CheckPicCode([FromBody]CheckPicCodeViewModel piccode)
{
JsonResult<bool> result = new JsonResult<bool>();
result.code = ;
result.msg = "OK";
if (piccode == null)
{
result.Result = false;
result.ResultMsg = "参数错误";
return Ok(result);
}
if (string.IsNullOrEmpty(piccode.token) || !RedisBase.ContainsKey(piccode.token))
{
result.Result = false;
result.ResultMsg = "验证码已过期";
return Ok(result);
}
result.Result = await Task.Run<bool>(() => {
bool flag = false;
VerCodePic codepic = RedisBase.Item_Get<VerCodePic>(piccode.token);
if (Math.Abs(codepic.Font1.X - piccode.x1) > 0.5 || Math.Abs(codepic.Font1.Y - piccode.y1) > 0.5
|| Math.Abs(codepic.Font2.X - piccode.x2) > 0.5 || Math.Abs(codepic.Font2.Y - piccode.y2) > 0.5
|| Math.Abs(codepic.Font3.X - piccode.x3) > 0.5 || Math.Abs(codepic.Font3.Y - piccode.y3) > 0.5
|| Math.Abs(codepic.Font4.X - piccode.x4) > 0.5 || Math.Abs(codepic.Font4.Y - piccode.y4) > 0.5)
{
flag = false;
result.ResultMsg = "验证码错误";
}
else
{
flag = true;
result.ResultMsg = "验证码正确";
}
return flag;
});
return Ok(result);
}