asp.net - 为什么 recaptcha.IsValid 总是返回 True

Question

为什么 recaptcha.IsValid 总是返回 True？

    Protected Sub CreateUserWizard1_CreatingUser(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.LoginCancelEventArgs) Handles CreateUserWizard1.CreatingUser
    Dim Captcha As RecaptchaControl = CType(CreateUserWizard1.CreateUserStep.ContentTemplateContainer.FindControl("recaptcha1"), RecaptchaControl)
    If Not Captcha.IsValid Then
        e.Cancel = True
    End If
End Sub

Answer 1

调用 Captcha.Validate()之前 Captcha.IsValid

    Protected Sub CreateUserWizard1_CreatingUser(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.LoginCancelEventArgs) Handles CreateUserWizard1.CreatingUser
    Dim Captcha As RecaptchaControl = CType(CreateUserWizard1.CreateUserStep.ContentTemplateContainer.FindControl("recaptcha1"), RecaptchaControl)
    Captcha.Validate()
    If Not Captcha.IsValid Then
        e.Cancel = True
    End If
End Sub