The Captcha module used in my blog
NuGet Package Manager
Install-Package Edi.Captcha
or .NET CLI
dotnet add package Edi.Captcha
services.AddSession(options =>
{
options.IdleTimeout = TimeSpan.FromMinutes(20);
options.Cookie.HttpOnly = true;
});
services.AddSessionBasedCaptcha();// Don't forget to add this line in your `Configure` method.
app.UseSession();or you can customize the options
services.AddSessionBasedCaptcha(option =>
{
option.Letters = "2346789ABCDEFGHJKLMNPRTUVWXYZ";
option.SessionName = "CaptchaCode";
option.CodeLength = 4;
});private readonly ISessionBasedCaptcha _captcha;
public SomeController(ISessionBasedCaptcha captcha)
{
_captcha = captcha;
}
[Route("get-captcha-image")]
public IActionResult GetCaptchaImage()
{
var s = _captcha.GenerateCaptchaImageFileStream(
HttpContext.Session,
100,
36
);
return s;
}app.UseSession().UseCaptchaImage(options =>
{
options.RequestPath = "/captcha-image";
options.ImageHeight = 36;
options.ImageWidth = 100;
});[Required]
[StringLength(4)]
public string CaptchaCode { get; set; }<div class="col">
<div class="input-group">
<div class="input-group-prepend">
<img id="img-captcha" src="~/captcha-image" />
</div>
<input type="text"
asp-for="CommentPostModel.CaptchaCode"
class="form-control"
placeholder="Captcha Code"
autocomplete="off"
minlength="4"
maxlength="4" />
</div>
<span asp-validation-for="CommentPostModel.CaptchaCode" class="text-danger"></span>
</div>_captcha.ValidateCaptchaCode(model.CommentPostModel.CaptchaCode, HttpContext.Session)To make your code look more cool, you can also write an Action Filter like this:
public class ValidateCaptcha : ActionFilterAttribute
{
private readonly ISessionBasedCaptcha _captcha;
public ValidateCaptcha(ISessionBasedCaptcha captcha)
{
_captcha = captcha;
}
public override void OnActionExecuting(ActionExecutingContext context)
{
var captchaedModel =
context.ActionArguments.Where(p => p.Value is ICaptchable)
.Select(x => x.Value as ICaptchable)
.FirstOrDefault();
if (null == captchaedModel)
{
context.ModelState.AddModelError(nameof(captchaedModel.CaptchaCode), "Captcha Code is required");
context.Result = new BadRequestObjectResult(context.ModelState);
}
else
{
if (!_captcha.Validate(captchaedModel.CaptchaCode, context.HttpContext.Session))
{
context.ModelState.AddModelError(nameof(captchaedModel.CaptchaCode), "Wrong Captcha Code");
context.Result = new ConflictObjectResult(context.ModelState);
}
else
{
base.OnActionExecuting(context);
}
}
}
}and then
services.AddScoped<ValidateCaptcha>();and then
public class YourModelWithCaptchaCode : ICaptchable
{
public string YourProperty { get; set; }
[Required]
[StringLength(4)]
public string CaptchaCode { get; set; }
}
[ServiceFilter(typeof(ValidateCaptcha))]
public async Task<IActionResult> SomeAction(YourModelWithCaptchaCode model)
{
// ....
}Refer to https://edi.wang/post/2018/10/13/generate-captcha-code-aspnet-core
此项目(Edi.Captcha.AspNetCore)及其配套组件均为免费开源的产品，仅用于学习交流，并且不直接向中国提供服务，中国用户请于下载后立即删除。
任何中国境内的组织及个人不得使用此项目(Edi.Captcha.AspNetCore)及其配套组件构建任何形式的面向中国境内用户的网站或服务。
不可用于任何违反中华人民共和国(含台湾省)或使用者所在地区法律法规的用途。
因为作者即本人仅完成代码的开发和开源活动(开源即任何人都可以下载使用)，从未参与用户的任何运营和盈利活动。
且不知晓用户后续将程序源代码用于何种用途，故用户使用过程中所带来的任何法律责任即由用户自己承担。