beego 接口生成验证码

var Cpt *captcha.Captcha

func init() {
    store := cache.NewMemoryCache()
    Cpt = captcha.NewWithFilter("/captcha/", store) //一定要写在构造函数里面，要不然第一次打开页面有可能是X
    Cpt.ChallengeNums = 4
}

//返回标识  如果是接口直接返回json数据
func (c *MainController) Get() {
    captcha, _ := Cpt.CreateCaptcha()
    c.Data["captcha"] = captcha
    c.TplName = "login.html"
}

<input type="text" name="captcha_id" value="{{.captcha}}">
<a class="captcha" href="javascript:"><img onclick="this.src=('/captcha/{{.captcha}}.png?reload='+(new Date()).getTime())" class="captcha-img" src="/captcha/{{.captcha}}.png"></a>

    if !Cpt.VerifyReq(c.Ctx.Request) {
        base = Base{2, "验证码错误", nil}
    }