DART用户代理检测

Question

我希望以便检测我的应用程序正在运行，主要是我想看看它是否正在运行，并且用户代理：

1. Chrome封装应用，
2. Chrome浏览器页面，
3. Android的web视图
4. 火狐

我运行此代码，为出发：

var ua = window.navigator.userAgent; 
print(ua); 

，并得到了这个输出线

Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/37.0.2062.76 (Dart) Safari/537.36 

但实际上我用DARTIUM运行它，并有镀铬/火狐/ IE11

任何想法！

Answer 1

从https://chromium.googlesource.com/external/dart/+/master/dart/sdk/lib/html/html_common/device.dart

/** 
* Utils for device detection. 
*/ 
class Device { 
    static bool _isOpera; 
    static bool _isIE; 
    static bool _isFirefox; 
    static bool _isWebKit; 
    static String _cachedCssPrefix; 
    static String _cachedPropertyPrefix; 
    /** 
    * Gets the browser's user agent. Using this function allows tests to inject 
    * the user agent. 
* Returns the user agent. 
    */ 
    static String get userAgent => window.navigator.userAgent; 
    /** 
    * Determines if the current device is running Opera. 
    */ 
    static bool get isOpera { 
    if (_isOpera == null) { 
     _isOpera = userAgent.contains("Opera", 0); 
    } 
    return _isOpera; 
    } 
    /** 
    * Determines if the current device is running Internet Explorer. 
    */ 
    static bool get isIE { 
    if (_isIE == null) { 
     _isIE = !isOpera && userAgent.contains("Trident/", 0); 
    } 
    return _isIE; 
    } 
    /** 
    * Determines if the current device is running Firefox. 
    */ 
    static bool get isFirefox { 
    if (_isFirefox == null) { 
     _isFirefox = userAgent.contains("Firefox", 0); 
    } 
    return _isFirefox; 
    } 
    /** 
    * Determines if the current device is running WebKit. 
    */ 
    static bool get isWebKit { 
    if (_isWebKit == null) { 
     _isWebKit = !isOpera && userAgent.contains("WebKit", 0); 
    } 
    return _isWebKit; 
    } 
    /** 
    * Gets the CSS property prefix for the current platform. 
    */ 
    static String get cssPrefix { 
    String prefix = _cachedCssPrefix; 
    if (prefix != null) return prefix; 
    if (isFirefox) { 
     prefix = '-moz-'; 
    } else if (isIE) { 
     prefix = '-ms-'; 
    } else if (isOpera) { 
     prefix = '-o-'; 
    } else { 
     prefix = '-webkit-'; 
    } 
    return _cachedCssPrefix = prefix; 
    } 
    /** 
    * Prefix as used for JS property names. 
    */ 
    static String get propertyPrefix { 
    String prefix = _cachedPropertyPrefix; 
    if (prefix != null) return prefix; 
    if (isFirefox) { 
     prefix = 'moz'; 
    } else if (isIE) { 
     prefix = 'ms'; 
    } else if (isOpera) { 
     prefix = 'o'; 
    } else { 
     prefix = 'webkit'; 
    } 
    return _cachedPropertyPrefix = prefix; 
    } 
    /** 
    * Checks to see if the event class is supported by the current platform. 
    */ 
    static bool isEventTypeSupported(String eventType) { 
    // Browsers throw for unsupported event names. 
    try { 
     var e = new Event.eventType(eventType, ''); 
     return e is Event; 
    } catch (_) { } 
    return false; 
    } 
} 

Answer 2

Dartium将自己标识为Chrome，但在用户代理中包含'（Dart）'。

，如果你的代码运行的浏览器扩展程序/应用程序通过检查chrome.runtime.id，你可以告诉例如：

// You'll likely need to reference this package: 
// https://pub.dartlang.org/packages/chrome 
if (window.chrome && window.chrome.runtime && window.chrome.runtime.id) { 
    window.alert('App!'); 
} 

如果您在Android应用程序的控制的时候，你可以用setUserAgentString来调整用户代理，所以你可以在你的网络应用中回应它：

myWebView.getSettings().setUserAgentString('Danny/1.0 not Chrome or IE or Webkit'); 

其他浏览器应该相对容易使用他们的用户代理字符串。