我试图在我的ASP MVC项目中获得验证码v2工作。客户端计算机有IE10/IE11，并在兼容性视图中显示所有intranet页面，这导致recaptcha不显示，因为它是预期的。
问题是它很少接受我的答案，即使它是正确的。它只是显示一个新的图像，但每隔一段时间我就会做对。有人有过这样的经历吗?如果您在IE中启用google.com的兼容性视图并访问演示站点，您可以尝试一下
reCAPTCHA要求兼容性视图不启用才能工作，参见:
https://support.google.com/recaptcha/?hl=en-GB 6223838
您正在看到reCaptcha的回退。看来你必须连续得到两个正确答案。然后它会给您一个响应代码，您可以将其复制并粘贴到<textarea>元素中。
所以你可能遇到的是你没有得到两个连续的验证码正确。
您可以通过向JavaScript资源添加fallback=true参数来测试回退验证码:
<script src="https://www.google.com/recaptcha/api.js?fallback=true" async defer></script>
正如@Coulton解释的那样，recaptcha不支持IE兼容模式
reCaptcha在javascript中使用了一个名为querySelectorAll和querySelector的函数。IE 11在兼容模式下呈现为IE 7.0, IE 7.0及以下版本似乎没有querySelectorAll和querySelector函数，这就是它失败的原因。
现在，我使用的是。net webforms，所以你可能要适应一点MVC，但这里是:
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="reCaptcha.aspx.cs" Inherits="reCaptcha" %>
<!DOCTYPE html>
<script type="text/javascript">
// this defines these functions if they don't exist.
if (!document.querySelectorAll) {
document.querySelectorAll = function (selectors) {
var style = document.createElement('style'), elements = [], element;
document.documentElement.firstChild.appendChild(style);
document._qsa = [];
style.styleSheet.cssText = selectors +
'{x-qsa:expression(document._qsa && document._qsa.push(this))}';
window.scrollBy(0, 0);
style.parentNode.removeChild(style);
while (document._qsa.length) {
element = document._qsa.shift();
element.style.removeAttribute('x-qsa');
elements.push(element);
}
document._qsa = null;
return elements;
};
}
if (!document.querySelector) {
document.querySelector = function (selectors) {
var elements = document.querySelectorAll(selectors);
return (elements.length) ? elements[0] : null;
};
}
</script>
<script src='https://cdnjs.cloudflare.com/ajax/libs/modernizr/2.8.3/modernizr.js' type="text/javascript"></script>
<script src='https://www.google.com/recaptcha/api.js' type="text/javascript"></script>
<script src='https://cdnjs.cloudflare.com/ajax/libs/jquery/1.3.2/jquery.min.js' type="text/javascript"></script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>reCaptcha Test</title>
</head>
<body>
<h1>reCaptcha Test</h1>
<form id="frmResult" runat="server">
<div class="g-recaptcha" data-sitekey=""></div>
<script type="text/javascript">
function IeVersion() {
//Set defaults
var value = {
IsIE: false,
TrueVersion: 0,
ActingVersion: 0,
CompatibilityMode: false
};
//Try to find the Trident version number
var trident = navigator.userAgent.match(/Trident/(d+)/);
if (trident) {
value.IsIE = true;
//Convert from the Trident version number to the IE version number
value.TrueVersion = parseInt(trident[1], 10) + 4;
}
//Try to find the MSIE number
var msie = navigator.userAgent.match(/MSIE (d+)/);
if (msie) {
value.IsIE = true;
//Find the IE version number from the user agent string
value.ActingVersion = parseInt(msie[1]);
} else {
//Must be IE 11 in "edge" mode
value.ActingVersion = value.TrueVersion;
}
//If we have both a Trident and MSIE version number, see if they're different
if (value.IsIE && value.TrueVersion > 0 && value.ActingVersion > 0) {
//In compatibility mode if the trident number doesn't match up with the MSIE number
value.CompatibilityMode = value.TrueVersion != value.ActingVersion;
}
return value;
}
var ie = IeVersion();
var reCaptchaApi = "";
$(document).ready(function () {
$('.g-recaptcha').each(function (index, obj) {
grecaptcha.render(obj, { 'sitekey': reCaptchaApi });
});
if (ie.CompatibilityMode) {
// loading it twice makes it load in compatibility mode.
$('.g-recaptcha').each(function (index, obj) {
grecaptcha.render(obj, { 'sitekey': reCaptchaApi });
});
}
});
</script>
</form>
</body>
</html>
允许reCaptcha V-2以兼容模式加载