.NET 6实现滑动验证码的示例详解

CaptchaData.cs

CaptchaData.cs：验证码的数据类实体

namespace SlideCaptcha.Model
{
public class CaptchaData
{
/// <summary>
/// id
/// </summary>
public string Id { get; set; }
/// <summary>
/// 背景图(含凹槽)
/// </summary>
public string BackgroundImage { get; set; }
/// <summary>
/// 滑动块图
/// </summary>
public string SliderImage { get; set; }

public CaptchaData(string id, string backgroundImage, string sliderImage)
{
Id = id;
BackgroundImage = backgroundImage;
SliderImage = sliderImage;
}
}
}

id表示验证码的id值，用于校验验证码，BackgroundImage 是验证码图片base64，包含了凹槽。凹槽模板在templates目录下。SliderImage 是滑块图片。模板在templates下。

CaptchaValidateData.cs

CaptchaValidateData.cs：验证码验证数据实体

namespace SlideCaptcha.Model
{
public class CaptchaValidateData
{
/// <summary>
/// 滑动比例
/// </summary>
public float Percent { get; set; }

/// <summary>
/// 容错值(校验时用，缺口位置与实际滑动位置匹配容错范围)
/// </summary>
public float Tolerant { get; set; }

public CaptchaValidateData(float percent, float tolerant)
{
Percent = percent;
Tolerant = tolerant;
}
}
}

ImageCaptchaInfo.cs

ImageCaptchaInfo.cs：证码图片信息实体

namespace SlideCaptcha.Model
{
public class ImageCaptchaInfo
{
/// <summary>
/// 背景图宽
/// </summary>
public int BackgroundImageWidth { get; set; }
/// <summary>
/// 背景图高
/// </summary>
public int BackgroundImageHeight { get; set; }
/// <summary>
/// 背景图
/// </summary>
public string BackgroundImageBase64 { get; set; }
/// <summary>
/// 滑动块图宽
/// </summary>
public int SliderImageWidth { get; set; }
/// <summary>
/// 滑动块图高
/// </summary>
public int SliderImageHeight { get; set; }
/// <summary>
/// 滑动块图
/// </summary>
public string SliderImageBase64 { get; set; }
}
}

验证码实体类的基类，滑动验证码、旋转验证码、点选验证码、拼接验证码都基于这个类。

Resource.cs

Resource.cs ：资源实体类

namespace SlideCaptcha.Model
{
public class Resource
{
public Resource(){}
/// <summary>
/// 资源数据
/// </summary>
public string Data { get; set; }

/// <summary>
/// 资源类型
/// </summary>
public string Type { get; set; }

/// <summary>
/// 构造函数
/// </summary>
/// <param name=\”type\”>资源类型</param>
/// <param name=\”data\”>资源数据</param>
public Resource(string type,string data)
{
Type = type;
Data = data;
}
}
}

资源数据，Data为要生成验证码图片路径。Type为类型，目前仅为本地文件，后期将扩展URL模式。

SliderImageCaptchaInfo.cs

SliderImageCaptchaInfo.cs：滑动验证码实体类

using SlideCaptcha.Exceptions;

namespace SlideCaptcha.Model
{
public class SliderImageCaptchaInfo : ImageCaptchaInfo
{
/// <summary>
/// 凹槽x坐标
/// </summary>
public int X { get; set; }
/// <summary>
/// 凹槽y坐标
/// </summary>
public int Y { get; set; }
/// <summary>
/// 凹槽位置百分比
/// </summary>
public float Percent
{
get
{
if (BackgroundImageWidth <= 0) return 0;
return 1.0f * X / BackgroundImageWidth;
}
}

public void Check()
{
// 校验
if (this.X <= 0) throw new SlideCaptchaException($\”SliderImageCaptchaInfo数据异常: {nameof(X)}小于等于0\”);
if (this.Y <= 0) throw new SlideCaptchaException($\”SliderImageCaptchaInfo数据异常: {nameof(Y)}小于等于0\”);
if (this.BackgroundImageWidth <= 0) throw new SlideCaptchaException($\”SliderImageCaptchaInfo数据异常: {nameof(BackgroundImageWidth)}小于等于0\”);
if (this.BackgroundImageHeight <= 0) throw new SlideCaptchaException($\”SliderImageCaptchaInfo数据异常: {nameof(BackgroundImageHeight)}小于等于0\”);
if (this.SliderImageWidth <= 0) throw new SlideCaptchaException($\”SliderImageCaptchaInfo数据异常: {nameof(SliderImageWidth)}小于等于0\”);
if (this.SliderImageHeight <= 0) throw new SlideCaptchaException($\”SliderImageCaptchaInfo数据异常: {nameof(SliderImageHeight)}小于等于0\”);
if (string.IsNullOrWhiteSpace(this.BackgroundImageBase64)) throw new SlideCaptchaException($\”SliderImageCaptchaInfo数据异常: {nameof(BackgroundImageBase64)}为空\”);
if (string.IsNullOrWhiteSpace(this.SliderImageBase64)) throw new SlideCaptchaException($\”SliderImageCaptchaInfo数据异常: {nameof(SliderImageBase64)}为空\”);
}
}
}

SlideTrack.cs

·SlideTrack.cs：滑动轨迹·

using SlideCaptcha.Exceptions;
using System;
using System.Collections.Generic;

namespace SlideCaptcha.Model
{
/// <summary>
/// 滑动轨迹
/// </summary>
public class SlideTrack
{
/// <summary>
/// 背景图片宽度(可能经过缩放，不是原始图片宽高)
/// </summary>
public int BackgroundImageWidth { get; set; }
/// <summary>
/// 背景图片高度(可能经过缩放，不是原始图片宽高)
/// </summary>
public int BackgroundImageHeight { get; set; }
/// <summary>
/// 滑块图片宽度(可能经过缩放，不是原始图片宽高)
/// </summary>
public int SliderImageWidth { get; set; }
/// <summary>
/// 滑块图片高度(可能经过缩放，不是原始图片宽高)
/// </summary>
public int SliderImageHeight { get; set; }
/// <summary>
/// 滑动开始时间(可能经过缩放，不是原始图片宽高)
/// </summary>
public DateTime StartTime { get; set; }
/// <summary>
/// 滑动结束时间
/// </summary>
public DateTime EndTime { get; set; }
/// <summary>
/// 轨迹
/// </summary>
public List<Track> Tracks { get; set; }

/// <summary>
/// 滑动比例
/// </summary>
public float Percent
{
get
{
if (this.BackgroundImageWidth <= 0) return -1;
if (this.Tracks.Count <= 0) return -1;

var lastTrack = this.Tracks[this.Tracks.Count – 1];
return 1.0f * lastTrack.X / this.BackgroundImageWidth;
}
}

public void Check()
{
// 校验
if (this.BackgroundImageWidth <= 0) throw new SlideCaptchaException($\”SlideTrack数据异常: {nameof(BackgroundImageWidth)}小于等于0\”);
if (this.BackgroundImageHeight <= 0) throw new SlideCaptchaException($\”SlideTrack数据异常: {nameof(BackgroundImageHeight)}小于等于0\”);
if (this.SliderImageWidth <= 0) throw new SlideCaptchaException($\”SlideTrack数据异常: {nameof(SliderImageWidth)}小于等于0\”);
if (this.SliderImageHeight <= 0) throw new SlideCaptchaException($\”SlideTrack数据异常: {nameof(SliderImageHeight)}小于等于0\”);
if (this.StartTime == DateTime.MinValue) throw new SlideCaptchaException($\”SlideTrack数据异常: {nameof(StartTime)}为空\”);
if (this.EndTime == DateTime.MinValue) throw new SlideCaptchaException($\”SlideTrack数据异常: {nameof(EndTime)}为空\”);
}

public void CheckTracks()
{
if (this.Tracks == null || this.Tracks.Count == 0) throw new SlideCaptchaException($\”SlideTrack数据异常: {nameof(Tracks)}为空\”);
}
}
}

TemplatePair.cs

·TemplatePair.cs：模板类·

namespace SlideCaptcha.Model
{
public class TemplatePair
{

public TemplatePair() { }

/// <summary>
/// 滑块资源
/// </summary>
public Resource Slider { get; set; }

/// <summary>
/// 凹槽资源
/// </summary>

public Resource Notch { get; set; }

/// <summary>
/// 模板类型
/// </summary>
public string TYPE { get; set; }

/// <summary>
/// 构造函数
/// </summary>
/// <param name=\”slider\”>滑块资源</param>
/// <param name=\”notch\”>凹槽资源</param>
/// <param name=\”type\”>末班类型</param>
public TemplatePair(Resource slider, Resource notch,string type)
{
Slider = slider;
Notch = notch;
TYPE = type;
}
/// <summary>
/// 创建模板
/// </summary>
/// <param name=\”slider\”>滑块资源</param>
/// <param name=\”notch\”>凹槽资源</param>
/// <returns></returns>
public static TemplatePair Create(Resource slider, Resource notch,string type)
{
return new TemplatePair(slider, notch,type);
}