title: React Native Call Screen Function from Header
body: <p>I have update password function inside <code>ScreenPassword</code>, but I want to update password by tapping Save button on screen header.</p>
  
  <p><strong>NavSettings.js</strong></p>
  
  <pre><code>const routeConfigs = {
      Password: {
          screen: ScreenPassword,
          navigationOptions: {
              headerTitle: 'Password',
              headerTintColor: '#000',
              headerRight: (
                  &lt;View style={styles.headerRight}&gt;
                      &lt;Button
                          style={styles.buttonHeader}
                          color='#000'
                          title="Save"
                          onPress={???????????} /&gt;
                  &lt;/View&gt;
              )
          }
      }
  }
  
  export default createStackNavigator(routeConfigs);
  </code></pre>
  
  <p><strong>ScreenPassword</strong></p>
  
  <pre><code>export default class ScreenPassword extends Component {
      updatePassword = () =&gt; {
  
      }
      render() {
          return (
              &lt;ScrollView style={styles.container}&gt;
                  &lt;View style={styles.boxForm}&gt;
                      &lt;TextInput
                          style={styles.textInput}
                          placeholder="Old Password"
                          secureTextEntry='true'
                      /&gt;
                      &lt;TextInput
                          style={styles.textInput}
                          placeholder="New Password"
                          secureTextEntry='true'
                      /&gt;
                      &lt;TextInput
                          style={styles.textInput}
                          placeholder="Confirm Password"
                          secureTextEntry='true'
                      /&gt;
                  &lt;/View&gt;
              &lt;/ScrollView&gt;
          )
      }
  }
  </code></pre>