Set title in createStackNavigator onPress - react-native

Question

I am making react native app. I have button and onPress i want to send headerTitle to createStackNavigator but i have some errors. I am sending title with setParams and in createStackNavigator i get it with getParam.
Why it is not working how is correct?
Code:
// page.js
<TouchableOpacity
onPress={() => navigate('Page2', {
this.props.navigation.setParams({Title: 'Title'});
})}>
// createStackNavigator
export default createStackNavigator(
{
Main: {
screen: Page1,
},
Page2: {
screen: Page2,
navigationOptions: ({ navigation }) => ({
headerTitle: navigation.state.getParam('Title', 'Default Title'),
}),
},
},
{
initialRouteName: 'Main',
}
);

Answer 1

The problem appears to be occurring in the operating order of the app.
Because the value is already obtained before the value is set, the value must be null or undefind, which is the value before the setting.
Try using it as a global function.
globalScreen
let TITLE = "defaultTitle"
function setT(data){
TITLE = data;
}
function getT() {
return TITLE;
}
export { setT, getT }
Usage
// page.js
import {setT } from "globalScreen"
<TouchableOpacity
onPress={() => {
setT("page2");
navigate('Page2'); }}>
// createStackNavigator
import {getT } from "globalScreen"
export default createStackNavigator(
{
Main: {
screen: Page1,
},
Page2: {
screen: Page2,
navigationOptions: ({ navigation }) => ({
headerTitle: getT(),
}),
},
},
{
initialRouteName: 'Main',
}
);