net mvc 验证码怎么实现

首先你要写一个验证码的Controller，这里我给你粘一个：

using System

using System.Collections.Generic

using System.Drawing

using System.Drawing.Imaging

using System.IO

using System.Linq

using System.Web

using System.Web.Mvc

namespace Demo.Controllers

{

    public class ValidateController : Controller

    {

        public FileResult ConfirmCode()

        {

            //生成4位随机数，并将其转为string型，传入session，4位数字由随机数从1000-9999中提取。

            string ConfirmCode = string.Empty

            Random rand = new Random()

            ConfirmCode = rand.Next(1000, 9999).ToString()

            Session["QuickChannelConfirmCode"] = ConfirmCode

            Random rand1 = new Random()

            Random rand2 = new Random()

            int red = rand1.Next(50)

            int green = rand2.Next(100)

            int blue1 = (red + green > 400) ? 0 : 400 - red - green

            int blue2 = (blue1 > 255) ? 255 : blue1

            Color col = Color.FromArgb(red, green, blue2)

            //int imageWidth = ConfirmCode.Length * 13

            Bitmap bmp = new Bitmap(135, 44)

            Graphics g = Graphics.FromImage(bmp)

            g.Clear(Color.LightGray)

            g.DrawRectangle(new Pen(Color.LightGray, 1), 0, 0, 134, 43)

            Font font = new Font("Harrington", 30)

            Brush brush = new SolidBrush(col)//col 为上文随机出的颜色

            Point po = new Point(15, 0)

            g.DrawString(ConfirmCode, font, brush, po)

            Response.ContentType = "image/jpeg"

            MemoryStream ms = new MemoryStream()

            bmp.Save(ms, ImageFormat.Jpeg)

            ms.Seek(0, SeekOrigin.Begin)

            return new FileStreamResult(ms, "image/jpeg")

        }

        public ActionResult CheckCode(string id)

        {

            //string quickChannalConfirmCode = Request.QueryString["id"].ToString()

            string quickChannalConfirmCode = id.ToUpper()

            if (Session["QuickChannelConfirmCode"] == null || "".Equals(Session["QuickChannelConfirmCode"].ToString()))

            {

                return Json(false, JsonRequestBehavior.AllowGet)

            }

            string yanzheng = Session["QuickChannelConfirmCode"].ToString()

            Session.Remove("QuickChannelConfirmCode")

            if (quickChannalConfirmCode == yanzheng)

            {

                return Json(true, JsonRequestBehavior.AllowGet)

            }

            else

            {

                return Json(false, JsonRequestBehavior.AllowGet)

            }

        }

    }

}

在页面上这样调用：

<img id="VerificationCodeImg" src="/Validate/ConfirmCode2" alt="验证码" />

然后还要在页面加上验证：

<script type="text/javascript">

function RefreshConfirmCode() {

    var rad_num = parseInt(1000*Math.random())

    $("#VerificationCodeImg").attr("src","/Validate/ConfirmCode/"+rad_num)

    $("#YanZhengMa").val("")

}

$(function () {

    $("#VerificationCodeImg").click(RefreshConfirmCode)

    $("#LoginButton").click(function(event) {

        var thisForm = $("form").first()

        if (thisForm.valid()) {

            var thisVerificationCode = $("#YanZhengMa").val()

            if (thisVerificationCode) {

                $.getJSON('/Validate/CheckCode', {id: thisVerificationCode}, function(json, textStatus) {

                    if (!json) {

                        RefreshConfirmCode()

                        thisForm.valid()

                    }

                    else {

                        thisForm.submit()

                    }

                })

            }

        }

        return false

    })

})

</script>

如何使用web api 保证数据的有效性？实际项目中不是什么数据提交过来都是符合要求的，况且在天朝还有N多河蟹的关键字等等。所以以下内容就是增加web api 数据验证.

第一步修改 实体模型

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public class UserInfo

{

public int Id { getset}

[Required]

[StringLength(20,ErrorMessage="名字太长了或者太短了",MinimumLength=4)]

public string Name { getset}

[RegularExpression(@"([2-5]\d)",ErrorMessage="年龄在20-50之间")]

public int Age { getset}

}

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注意：需要添加 System.ComponentModel.DataAnnotations引用

第二步增加Filter

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public class ValidationAttribute : ActionFilterAttribute

{

public override void OnActionExecuting(HttpActionContext actionContext)

{

if (!actionContext.ModelState.IsValid)

{

actionContext.Response = actionContext.Request.CreateErrorResponse(

HttpStatusCode.BadRequest,

actionContext.ModelState)

}

}

}

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注意：需要引入命名空间

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using System.Web

using System.Web.Http.Filters

using System.Web.Http.ModelBinding

using System.Web.Http.Controllers

using System.Net.Http

using System.Net

using Newtonsoft.Json.Linq

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第三步 注册Filter

打开 webApiConfig

添加代码

config.Filters.Add(new Filters.ValidationAttribute())

第四步 编写页面

引入js/CSS

<link href="Content/Site.css" rel="stylesheet" type="text/css" />

<script src="Scripts/jquery-1.7.1.min.js" type="text/javascript"></script>

<script src="Scripts/knockout-2.1.0.js" type="text/javascript"></script>

<script src="Scripts/jquery.validate.min.js" type="text/javascript"></script>

<script src="Scripts/jquery.validate.unobtrusive.min.js" type="text/javascript"></script>

拷贝HTMLPage2的内容稍作修改

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<label for="text">

名称</label>

<input id="name" name="name" data-val="true" data-val-required="是不是忘记输入名称了?" type="text"

value="" />

<span class="field-validation-valid" data-valmsg-for="name" data-valmsg-replace="true">

</span>

<label for="text">

年龄</label>

<input id="age" name="age" type="text" data-val="true" data-val-required="年龄也是必须输入的哦!"

value="" />

<span class="field-validation-valid" data-valmsg-for="age" data-valmsg-replace="true">

</span>

<br />

<button type="submit">

Submit</button>

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增加js，这段js是将服务返回的错误消息进行显示

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$.validator.addMethod("failure", function () { return false})

$.validator.unobtrusive.adapters.addBool("failure")

$.validator.unobtrusive.revalidate = function (form, validationResult) {

$.removeData(form[0], 'validator')

var serverValidationErrors = []

for (var property in validationResult) {

var elementId = property.toLowerCase()

elementId = elementId.substr(elementId.indexOf('.') + 1)

var item = form.find('#' + elementId)

serverValidationErrors.push(item)

item.attr('data-val-failure', validationResult[property][0])

jQuery.validator.unobtrusive.parseElement(item[0])

}

form.valid()

$.removeData(form[0], 'validator')

$.each(serverValidathttp://www.yingtaow.com/sitemap.xml?ionErrors, function () {

this.removeAttr('data-val-failure')

jQuery.validator.unobtrusive.parseElement(this[0])

})

}

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增加服务器返回错误消息显示 *** 作

400 /* BadRequest */: function (jqxhr) {

var validationResult = $.parseJSON(jqxhr.responseText)

$.validator.unobtrusive.revalidate(form, validationResult.ModelState)

}

浏览测试得到效果

1 没有任何输入

2 输入不合法

本篇完整代码:/Files/risk/web api 5/MvcApplication1.rar

public class RegisterController : ApiController

02

{private ApplicationUserManager UserManager

03

{get

04

{return Request.GetOwinContext().GetUserManager<ApplicationUserManager>()

05

}

06

}public IHttpActionResult Post(RegisterApiModel model)

07

{if (!ModelState.IsValid)

08

{return BadRequest(ModelState)

09

}var user = new ApplicationUser

10

{

11

Email = model.Email,

12

UserName = model.Email,

13

EmailConfirmed = true

14

}

15

var result = UserManager.Create(user, model.Password)

16

return result.Succeeded ? Ok() : GetErrorResult(result)

17

}

18

private IHttpActionResult GetErrorResult(IdentityResult result)

19

{

20

if (result == null)

21

{

22

return InternalServerError()

23

}

24

if (result.Errors != null)

25

{

26

foreach (var error in result.Errors)

27

{

28

ModelState.AddModelError("", error)

29

}

30

}

31

if (ModelState.IsValid)

32

{

33

// No ModelState errors are available to send, so just return an empty BadRequest.

34

return BadRequest()

35

}

36

return BadRequest(ModelState)

37

}

38

}

...用JS验证或者用验证控件啊。

不过一般客户端验证了 服务3、端还会验证 。 因为有的浏览器不支持Javascript

客户端验证：

<script language="javascript" type="text/javascript">

function fn()

{

var str = document.getElementById("TextBox1").value

if(str.length==0)

{

alert("输入不能为空")

document.getElementById("TextBox1").focus()

return false

}

}

</script>

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