icon in component header is not showing

Question

I am following the doc example here to add a plus + to component header:

import React, { Component} from 'react';
import { SectionList, View, Image, StyleSheet, Text, TouchableOpacity, Platform, TouchableHighlight, AppRegistry } from 'react-native';
import {Icon } from "react-native-elements";

export default class Event extends React.Component {

    static navigationOptions = ({navigation}) => {
      console.log("in event header");
      return {
        headerTitle: 'Event',
        headerRight: (
          <TouchableOpacity>
            <Icon 
              name="plus" 
              size={30} 
              type='octicon' 
              onPress={navigation.getParam('navToNewEvent')}
              />
          </TouchableOpacity>
          ),
        };
    }

    _navToNewEvent = () => {
      console.log("Route to new event");
      this.props.navigation.navigate("NewEvent");
    };

    async componentDidMount(){
      this.props.navigation.setParams({ navToNewEvent: this._navToNewEvent })
    ....
    }

However the plus + is not showing in component header:

What is missing in my code above?

UPDATE: the navigation code before component Event is:

return createBottomTabNavigator(
          {
            Event: {screen: EventStack},
            Group: {screen: GroupStack},
            Contact: {screen: ContactStack},

          }, bottomTabNavOptions
      );

const bottomTabNavOptions =  {
  defaultNavigationOptions: ({ navigation }) => ({
    tabBarIcon: ({ focused, tintColor }) => {
      const { routeName } = navigation.state;
      console.log("route name", routeName);
      let iconName;
      if (routeName === 'Event') {
        iconName = `list-unordered`;
      } else if (routeName === 'NewEvent') {
        iconName = "kebab-horizontal";
      } else if (routeName === 'NewUser') {
        iconName = `person`;
      } else if (routeName === 'ListUser') {
        iconName = `organization`
      }

      return <Icon name={iconName} size={30} color={tintColor} type='octicon' />;
    },
  }),
  tabBarOptions: {
    activeTintColor: 'tomato',
    inactiveTintColor: 'gray',
  },
};

const EventStack = createStackNavigator({

      Event:  {
        screen: EventWithSelf,
        navigationOptions: {
          title: 'Event',
        },
      },
      NewEvent: {
        screen: NeweventWithSelf,
        navigationOptions: {
          title: 'New Event',
        },
      },

      EditEvent: {
        screen: EditEventWithSelf,
        navigationOptions: {
          title: 'Edit Event',
        },
      },

      Chat: {
        screen: ChatWithSocket,
        navigationOptions: {
          title: 'Chat',
        },

      },     
    });

Answer 1

Simply looking at the code doesn't seem wrong. There is one catch. Would you like to modify this?

static navigationOptions = ({navigation}) => {
      console.log("in event header");
      return {
        title: 'Event',
        headerRight: (
          <TouchableOpacity>
            <Icon 
              name="plus" 
              size={30} 
              type='octicon' 
              onPress={() => navigation.getParam('navToNewEvent')}
              />
          </TouchableOpacity>
          ),
        };
    }

You can use defaultNavigationOptions The Event tab you represent is not a single screen. As a common header, configure the title and button in defaultNavigationOptions.

defaultNavigationOptions: ({ navigation }) => ({
...
 headerTitle: 'Event',
        headerRight: (
          <TouchableOpacity>
            <Icon 
              name="plus" 
              size={30} 
              type='octicon' 
              onPress={navigation.getParam('navToNewEvent')}
              />
          </TouchableOpacity>
          ),