title: How to change the title of the NavigatorIOS without changing the route in React Native
body: <p>I have a NavigatorIOS and TabBarIOS in my app. I want to change the title of the current route when a tab selected. </p>
  
  <h1>the first way that didn't work</h1>
  
  <p>While creating NavigatorIOS, I user a variable at <strong>state</strong> object but updating state didn't change the title. (even though the render is called again)</p>
  
  <pre><code>onTabChanged: function (title) {
    this.setState({
      selectedTab: title,
    });
  },
  
  render() {
    return (
      &lt;NavigatorIOS
      ...
      initialRoute={{
        component: Tabs,
        title: this.state.selectedTab,
        passProps: {
          onTabChanged: this.onTabChanged
        }
      }}
      /&gt;
    );
  },
  </code></pre>
  
  <h1>the second way that didn't work</h1>
  
  <p>I also tried updating the state of the the NavigatorIOS which I referred as <strong>nav</strong>. There is a <strong>routeStack</strong> object in the <strong>state</strong> of the NavigatorIOS which keeps an array of the route items. So I updated the array via <strong>setState</strong> of the NavigatorIOS but it didn't work either.</p>
  
  <h1>the third way that didn't work</h1>
  
  <p>I tried to change the title from <strong>Objective C</strong> as <strong>Native Module</strong> but I couldn't reach to that specific navigation bar from the NSObject.</p>
  
  <p>I hope someone can help.</p>