如果Angular 2应用程序不支持浏览器，我在演示警告页面时遇到问题。我曾尝试使用路由系统，但实际上它并没有帮助。这是我的索引页面。如果浏览器不受支持，如何重定向（显示给用户）警告页面？也许我需要在body上添加一些额外的脚本，但<app>标签怎么样？
<!DOCTYPE html>
<html>
<head>
<base href="/">
</head>
<body>
<app>Loading...</app>
</body>
</html>
我认为你应该使用清晰的JavaScript代码：
var BrowserDetect = {
init: function () {
this.browser = this.searchString(this.dataBrowser) || "Other";
this.version = this.searchVersion(navigator.userAgent) || this.searchVersion(navigator.appVersion) || "Unknown";
},
searchString: function (data) {
for (var i = 0; i < data.length; i++) {
var dataString = data[i].string;
this.versionSearchString = data[i].subString;
if (dataString.indexOf(data[i].subString) !== -1) {
return data[i].identity;
}
}
},
searchVersion: function (dataString) {
var index = dataString.indexOf(this.versionSearchString);
if (index === -1) {
return;
}
var rv = dataString.indexOf("rv:");
if (this.versionSearchString === "Trident" && rv !== -1) {
return parseFloat(dataString.substring(rv + 3));
} else {
return parseFloat(dataString.substring(index + this.versionSearchString.length + 1));
}
},
dataBrowser: [
{string: navigator.userAgent, subString: "Edge", identity: "MS Edge"},
{string: navigator.userAgent, subString: "MSIE", identity: "Explorer"},
{string: navigator.userAgent, subString: "Trident", identity: "Explorer"},
{string: navigator.userAgent, subString: "Firefox", identity: "Firefox"},
{string: navigator.userAgent, subString: "Opera", identity: "Opera"},
{string: navigator.userAgent, subString: "OPR", identity: "Opera"},
{string: navigator.userAgent, subString: "Chrome", identity: "Chrome"},
{string: navigator.userAgent, subString: "Safari", identity: "Safari"}
]
};
BrowserDetect.init();
document.write("You are using <b>" + BrowserDetect.browser + "</b> with version <b>" + BrowserDetect.version + "</b>");您可以在此问题中找到更多检测更多浏览器的方法：Correct way to use Modernizr to detect IE?
如果您想在Angular应用程序中支持IE 11/10/9 - 添加polyfill。对于旧的IE版本检测，请使用以下代码：
function detectIE() {
var ua = window.navigator.userAgent;
var msie = ua.indexOf('MSIE ');
if (msie > 0) {
// IE 10 or older => return version number
return parseInt(ua.substring(msie + 5, ua.indexOf('.', msie)), 10);
}
var trident = ua.indexOf('Trident/');
if (trident > 0) {
// IE 11 => return version number
var rv = ua.indexOf('rv:');
return parseInt(ua.substring(rv + 3, ua.indexOf('.', rv)), 10);
}
var edge = ua.indexOf('Edge/');
if (edge > 0) {
// Edge (IE 12+) => return version number
return parseInt(ua.substring(edge + 5, ua.indexOf('.', edge)), 10);
}
// other browser
return false;
}
要么
<!--[if lt IE 9]>
Place Content here for Users of Internet Explorer 9 or lower.
<![endif]-->
在HTML代码中。