react-navigation/example/src/ModalPresentation.tsx

import * as React from 'react';
import { Button, View, Text } from 'react-native';
import {
  createStackNavigator,
  TransitionPresets,
  NavigationStackScreenProps,
} from 'react-navigation-stack';

class ListScreen extends React.Component<NavigationStackScreenProps> {
  static navigationOptions = {
    title: 'My Modal',
  };

  render() {
    return (
      <View style={{ flex: 1, alignItems: 'center', justifyContent: 'center' }}>
        <Text>List Screen</Text>
        <Text>A list may go here</Text>
        <Button
          title="Go to Details"
          onPress={() => this.props.navigation.navigate('Details')}
        />
        <Button
          title="Go back to all examples"
          onPress={() => this.props.navigation.navigate('Index')}
        />
      </View>
    );
  }
}

class DetailsScreen extends React.Component<NavigationStackScreenProps> {
  static navigationOptions = {
    headerShown: false,
  };

  render() {
    return (
      <View style={{ flex: 1, alignItems: 'center', justifyContent: 'center' }}>
        <Text>Details Screen</Text>
        <Button
          title="Go to Details... again"
          onPress={() => this.props.navigation.push('Details')}
        />
        <Button
          title="Go to List"
          onPress={() => this.props.navigation.navigate('List')}
        />
        <Button
          title="Go back"
          onPress={() => this.props.navigation.goBack()}
        />
        <Button
          title="Go back to all examples"
          onPress={() => this.props.navigation.navigate('Index')}
        />
      </View>
    );
  }
}

export default createStackNavigator(
  {
    List: ListScreen,
    Details: DetailsScreen,
  },
  {
    mode: 'modal',
    defaultNavigationOptions: {
      ...TransitionPresets.ModalPresentationIOS,
      cardOverlayEnabled: true,
      gestureEnabled: true,
    },
  }
);