1 var App = Backbone.Router.extend({
 2     routes: {
 3       "": "index",    // #index
 4       "index": "index",    // #index
 5       "detail": "detail"    // #detail
 6     },
 7     index: function () {
 8       var index = new Index(this.interface);
 9   
10    },
11    detail: function () {
12      var detail = new Detail(this.interface);
13  
14    },
15    initialize: function () {
16  
17    },
18    interface: {
19      forward: function (url) {
20        window.location.href = (‘#‘ + url).replace(/^#+/, ‘#‘);
21      }
22  
23    }
24 });

Backbone.history.start();

 1 var History = Backbone.History = function () {
 2   this.handlers = [];
 3   _.bindAll(this, ‘checkUrl‘);
 4 
 5   // Ensure that `History` can be used outside of the browser.
 6   if (typeof window !== ‘undefined‘) {
 7     this.location = window.location;
 8     this.history = window.history;
 9   }
10 };

 1 start: function(options) {
 2       if (History.started) throw new Error("Backbone.history has already been started");
 3       History.started = true;
 4 
 5       // Figure out the initial configuration. Do we need an iframe?
 6       // Is pushState desired ... is it available?
 7       this.options          = _.extend({root: ‘/‘}, this.options, options);
 8       this.root             = this.options.root;
 9       this._wantsHashChange = this.options.hashChange !== false;
10       this._wantsPushState  = !!this.options.pushState;
11       this._hasPushState    = !!(this.options.pushState && this.history && this.history.pushState);
12       var fragment          = this.getFragment();
13       var docMode           = document.documentMode;
14       var oldIE             = (isExplorer.exec(navigator.userAgent.toLowerCase()) && (!docMode || docMode <= 7));
15 
16       // Normalize root to always include a leading and trailing slash.
17       this.root = (‘/‘ + this.root + ‘/‘).replace(rootStripper, ‘/‘);
18 
19       // 老版本ie以及希望使用hashChange, 使用iframe实现
20       if (oldIE && this._wantsHashChange) {
21         var frame = Backbone.$(‘<iframe src="javascript:0" tabindex="-1">‘);
22         this.iframe = frame.hide().appendTo(‘body‘)[0].contentWindow;
23         this.navigate(fragment);
24       }
25       
26       // Depending on whether we‘re using pushState or hashes, and whether
27       // ‘onhashchange‘ is supported, determine how we check the URL state.
28       if (this._hasPushState) {
29         Backbone.$(window).on(‘popstate‘, this.checkUrl);
30       } else if (this._wantsHashChange && (‘onhashchange‘ in window) && !oldIE) {
31         Backbone.$(window).on(‘hashchange‘, this.checkUrl);
32       } else if (this._wantsHashChange) {
33         this._checkUrlInterval = setInterval(this.checkUrl, this.interval);
34       }   
           /* 取决于选择hash还是pushState 
 　　　　　　如果使用 pushState，调用方法
           Backbone.history.start({ pushState: true });
           */
35 
36       // Determine if we need to change the base url, for a pushState link
37       // opened by a non-pushState browser.
38       this.fragment = fragment;
39       var loc = this.location;
40 
41       // Transition from hashChange to pushState or vice versa if both are
42       // requested.
43       if (this._wantsHashChange && this._wantsPushState) {
44 
45         // If we‘ve started off with a route from a `pushState`-enabled
46         // browser, but we‘re currently in a browser that doesn‘t support it...
47         if (!this._hasPushState && !this.atRoot()) {
48           this.fragment = this.getFragment(null, true);
49           this.location.replace(this.root + ‘#‘ + this.fragment);
50           // Return immediately as browser will do redirect to new url
51           return true;
52 
53         // Or if we‘ve started out with a hash-based route, but we‘re currently
54         // in a browser where it could be `pushState`-based instead...
55         } else if (this._hasPushState && this.atRoot() && loc.hash) {
56           this.fragment = this.getHash().replace(routeStripper, ‘‘);
57           this.history.replaceState({}, document.title, this.root + this.fragment);
58         }
59 
60       }
61 
62       if (!this.options.silent) return this.loadUrl();
63     }

loadUrl: function (fragmentOverride) {
  var fragment = this.fragment = this.getFragment(fragmentOverride);
  var matched = _.any(this.handlers, function (handler) {      // handlers是routes定义的集合，实例化Router时导入
    if (handler.route.test(fragment)) {
      handler.callback(fragment);
      return true;
    }
  });
  return matched;
}