I wrote code and did shift + command + a in iOS simulator but I could see mode is not changed from console.log what is the problem?
import {createBottomTabNavigator} from "#react-navigation/bottom-tabs";
import { useColorScheme } from "react-native-web";
import Movies from "../screens/Movies";
import Search from "../screens/Search";
import Tv from "../screens/Tv";
const Tab = createBottomTabNavigator();
const Tabs = () => {
const colorScheme = useColorScheme();
console.log(colorScheme);
return(
<Tab.Navigator >
<Tab.Screen name="Movies" component={Movies} options={{
}}/>
<Tab.Screen name="Tv" component={Tv}/>
<Tab.Screen name="Search" component={Search}/>
</Tab.Navigator>
);
}
export default Tabs;
first :
import * as RN from "react-native";
import {
DarkTheme,
DefaultTheme,
NavigationContainer,
} from "#react-navigation/native";
in App.js :
let cs = RN.useColorScheme();
let isDark = cs === "dark";
let theme = isDark ? DarkTheme : DefaultTheme; // or your custom theme [1]
...
...
<NavigationContainer theme={theme}>
<Tabs />
</NavigationContainer>
...
[1] : react-navigation theme
and if you want use react-navigation theme object in functional components :
import { useTheme } from "#react-navigation/native";
and after defining your function component :
let { colors, dark } = useTheme();
and in JSX :
...
<View
style={{
width: 100,
height: 175,
margin: 10,
alignItems: "center",
borderWidth: 1,
backgroundColor: colors.primary,
borderRadius: 10,
justifyContent: "space-evenly",
}}
/>
...
The getColorScheme() hook will always return light when debugging with Chrome. Disable debugging to return dark.
Example to debug
const colorScheme = useColorScheme();
useEffect(() => {
if (colorScheme) {
Alert.alert(colorScheme)
}
}, [colorScheme])
Related
What I want
I'm trying to animate the react navigation native stack header by changing the background from a transparent to a gray color when the user scrolls down. I was reading the documentation and it suggests using the navigation.setOptions to interact with the screen info.
I am using react-native-reanimated to capture the scroll value and change it when the user interacts with the screen.
The problem
I'm capturing the scroll value and using it inside the setOptions method but it doesn't work, it just doesn't execute the changes.
import React from 'react';
import {
useAnimatedScrollHandler,
useSharedValue,
} from 'react-native-reanimated';
const MyScreen = ({ navigation }) => {
const scrollY = useSharedValue(0);
const scrollHandler = useAnimatedScrollHandler({
onScroll: (e) => {
scrollY.value = e.contentOffset.y;
},
});
React.useLayoutEffect(() => {
navigation.setOptions({
headerStyle: {
backgroundColor: scrollY.value > 0 ? 'black' : 'transparent',
},
headerTransparent: scrollY.value === 0,
});
}, [ navigation, scrollY.value ]);
}
Deps
"react-native": "0.67.2",
"react-native-reanimated": "2.9.1",
"#react-navigation/native": "^6.0.6",
"#react-navigation/native-stack": "^6.2.5",
It's possible to animate the Native Stack header, but since only Animated components accept animated styles in Reanimated 2, you'd probably have to create a new component for the header (an Animated.Something)...
We can achieve this by using the header option, which can be found here.
A simple example built with Expo:
import React from "react";
import { StatusBar } from "expo-status-bar";
import { StyleSheet, Text, View } from "react-native";
import { NavigationContainer, useNavigation } from "#react-navigation/native";
import { createNativeStackNavigator } from "#react-navigation/native-stack";
import Animated, {
useSharedValue,
useAnimatedStyle,
useAnimatedScrollHandler,
interpolateColor,
} from "react-native-reanimated";
const Stack = createNativeStackNavigator();
const styles = StyleSheet.create({
container: {
flex: 1,
backgroundColor: "white",
},
item: {
padding: 20,
margin: 15,
backgroundColor: "whitesmoke",
},
header: {
paddingTop: 50,
padding: 15,
borderColor: "whitesmoke",
borderBottomWidth: 1,
},
headerTitle: {
fontSize: 20,
fontWeight: "bold",
},
});
function WelcomeScreen() {
const navigation = useNavigation();
const translationY = useSharedValue(0);
const scrollHandler = useAnimatedScrollHandler((event) => {
translationY.value = event.contentOffset.y;
});
const aStyle = useAnimatedStyle(() => ({
backgroundColor: interpolateColor(
translationY.value,
[0, 50],
["white", "skyblue"],
"RGB"
),
}));
React.useLayoutEffect(() => {
navigation.setOptions({
header: () => (
<Animated.View style={[styles.header, aStyle]}>
<Text style={styles.headerTitle}>Testing</Text>
</Animated.View>
),
});
}, [aStyle, navigation]);
return (
<View style={styles.container}>
<Animated.ScrollView onScroll={scrollHandler} scrollEventThrottle={16}>
{Array(15)
.fill(0)
.map((_, index) => (
<View style={styles.item} key={`${index}`}>
<Text>Item {`${index}`}</Text>
</View>
))}
</Animated.ScrollView>
<StatusBar style="auto" />
</View>
);
}
export default function App() {
return (
<NavigationContainer>
<Stack.Navigator>
<Stack.Screen component={WelcomeScreen} name="Welcome" />
</Stack.Navigator>
</NavigationContainer>
);
}
Note that in this example, we're passing an Animated.View to the header option, passing our animated style (aStyle) to it as a style.
Also, just like you did, I'm using useAnimatedScrollHandler to track the scroll position, and interpolating (with interpolateColor) the backgroundColor of the header accordingly (between 'white' and 'skyblue', so it's easier to visualize).
Uploaded this example to this Snack so you can easily test it if you want.
I Hope this helps you solve your problem!
My idea is to have nav.js contain the navigation container for my mobile application, along with all of the screens here (i.e. the homescreen). This file would theoretically let me include buttons in another file that would let me navigate to the screen in the nav.js file that I specified with the button.
I made a constant for this called NavBar and exported it, but when I tried to import into my photo.js file (an example file where I want to include a button that lets me navigate to my 'Tasks' screen), I got the error:
Error: Looks like you have nested a 'NavigationContainer' inside another. Normally you need only one container at the root of the app, so this was probably an error. If this was intentional, pass 'independent={true}' explicitly. Note that this will make the child navigators disconnected from the parent and you won't be able to navigate between them.
I tried simply making my own button in photo.js instead of :
<Button title="Go to tasks" color="lightblue" onPress={() => navigation.navigate('Tasks')}/>, but that only gave me the error that the variable navigation could not be found.
nav.js
import React from 'react';
import { NavigationContainer } from '#react-navigation/native';
import { createNativeStackNavigator } from '#react-navigation/native-stack';
import { StyleSheet, View, Button, ScrollView } from 'react-native';
import TaskApp from './taskapp';
import AddTank from './tank';
const NavBar = () => {
const Stack = createNativeStackNavigator();
{/* Homescreen */}
const HomeScreen = ( {navigation} ) => {
return (
<ScrollView style={homeStyle.container}>
<AddTank />
<Button title="Go to tasks" color="lightblue" onPress={() => navigation.navigate('Tasks')}/>
</ScrollView>
)
}
{/* Default config */}
const Config = ( {navigation } ) => {
return (
<View></View>
)
}
return (
<NavigationContainer>
<Stack.Navigator initialRouteName='Home'>
<Stack.Screen name="Home" component={HomeScreen}/>
<Stack.Screen name="Tasks" component={TaskApp}/>
<Stack.Screen name="Config" component={Config}/>
</Stack.Navigator>
</NavigationContainer>
)
}
const homeStyle = StyleSheet.create({
container: {
flex: 1,
backgroundColor: '#E8EAED',
},
tasks: {
flex: 1,
height: 30,
width: 30,
backgroundColor: '#E8EAED',
},
});
export default NavBar;
photo.js
import React, {useState, useEffect} from 'react';
import { StyleSheet, Text, View, Button, Image, ImageBackground } from 'react-native';
import { NavigationContainer, StackActions } from '#react-navigation/native';
import { createNativeStackNavigator } from '#react-navigation/native-stack';
import * as ImagePicker from 'expo-image-picker';
import NavBar from './nav';
const AddPhoto = () => {
const add = {uri: 'https://media.discordapp.net/attachments/639282516997701652/976293252082839582/plus.png?width=461&height=461'}
const Stack = createNativeStackNavigator();
const [hasGalleryPermission, setHasGalleryPermission] = useState(null);
const[ image, setImage ] = useState(null);
useEffect(() => {
(async () => {
const galleryStatus = await ImagePicker.requestCameraMediaLibraryPermissionAsync();
setHasGalleryPermission(galleryStatus.status === 'granted');
})();
}, []);
const pickImage = async () => {
let result = await ImagePicker.launchImageLibraryAsync({
mediaTypes: ImagePicker.MediaTypeOptions.Images,
allowsEditing: true,
aspect: [4,3],
quality:1,
});
console.log(result);
if (!result.cancelled){
setImage(result.uri);
}
};
if (hasGalleryPermission === false){
return <Text>No access to internal storage.</Text>
}
return (
<View style={styles.container}>
{image && <ImageBackground source={{uri: image}} style={styles.tankPhoto}/>}
<Button title="Add photo" color="lightgreen" onPress={() => pickImage()} />
<NavBar />
</View>
)
}
const styles = StyleSheet.create({
container: {
borderColor: '#C0C0C0',
borderWidth: 1,
backgroundColor: '#FFF',
borderRadius: 50,
width: 330,
flex: 1,
alignItems: 'center',
marginLeft: 'auto',
marginRight: 'auto',
margin: 30,
},
tankPhoto: {
flex: 1,
height: 150,
width: 200,
borderWidth: 1,
margin: 25,
},
})
export default AddPhoto;
What am I doing wrong, or is there a better way to do this? What I need:
let me include buttons in another file that would let me navigate to the screen in the nav.js file that I specified with the button.
React native navigation documentation: https://reactnavigation.org/docs/getting-started
Move these lines outside the NavBar component:
const Stack = createNativeStackNavigator();
{/* Homescreen */}
const HomeScreen = ( {navigation} ) => {
return (
<ScrollView style={homeStyle.container}>
<AddTank />
<Button title="Go to tasks" color="lightblue" onPress={() => navigation.navigate('Tasks')}/>
</ScrollView>
)
}
{/* Default config */}
const Config = ( {navigation } ) => {
return (
<View></View>
)
}
I ended up making this work. I defined
const navigation = useNavigation();
in my code (under AddPhoto constant) and imported:
import { useNavigation } from '#react-navigation/native'; in the same file (photo.js).
I am using react-navigation 5 in my mobile app and I am stuck in implementing a log-off feature.
The scenario is I have a stack navigator and a bottom tab navigator in my app. The app starts with the stack navigator (Login feature and Reset Password Feature) and on login goes to the dashboard Page which is from the bottom tab navigator. Now on the Dashboard page, I am implementing a logout feature which when clicked should take me to the login page (part of stack navigator), and no matter what I try it keeps giving me errors like these
The action 'RESET' with payload {"index":0,"routes":[{"name":"AuthNavigator"}]} was not handled by any navigator.
Here are my code snippets right from start
Component Called from App.js
import React, { useState, useEffect, useContext } from "react";
import { ActivityIndicator } from "react-native";
import AsyncStorage from '#react-native-async-storage/async-storage';
import { Center } from "../../components/Center";
import { AuthContext } from "../authentication/AuthProvider";
import { NavigationContainer } from "#react-navigation/native";
import { AuthNavigator } from "./AuthNavigator";
import { MainTabNavigator } from "./MainTabNavigator";
export default function App() {
const { user, login } = useContext(AuthContext);
const [loading, setLoading] = useState(true);
useEffect(() => {
// check if the user is logged in or not
//AsyncStorage.removeItem("user") //- uncomment this and refresh emulator to start from login screen
AsyncStorage.getItem("user")
.then(userString => {
if (userString) {
login();
}
setLoading(false);
})
.catch(err => {
console.log(err);
});
}, []);
if (loading) {
return (
<Center>
<ActivityIndicator size="large" />
</Center>
);
}
return (
<NavigationContainer>
{user ? <MainTabNavigator /> : <AuthNavigator />}
</NavigationContainer>
);
}
AuthNavigator.js
import React from "react";
import { createStackNavigator } from '#react-navigation/stack';
import Login from '../authentication/Login';
import ResetPassword from '../authentication/ResetPassword';
import { MainTabNavigator } from "./MainTabNavigator";
const Stack = createStackNavigator();
export const AuthNavigator = () => {
return (
<Stack.Navigator initialRouteName="Login">
<Stack.Screen name="Login" component={Login} />
<Stack.Screen name="ResetPassword" options={{headerTitle: "Reset Password"}} component={ResetPassword} />
</Stack.Navigator>
);
}
MainTabNavigator.js
import * as React from 'react';
import { Text, View, Image, StyleSheet, Platform } from 'react-native';
import { createBottomTabNavigator } from '#react-navigation/bottom-tabs';
import DashboardView from '../dashboard/DashboardView';
import Search from '../searchLoan/Search';
import { colors } from '../../styles';
const iconHome = require('../../../assets/images/tabbar/home.png');
const iconGrids = require('../../../assets/images/tabbar/grids.png');
const searchIcon = require('../../../assets/images/pages/search_24px.png');
const Tab = createBottomTabNavigator();
const tabData = [
{
name: 'Dashboard',
component: DashboardView,
icon: iconHome,
},
{
name: 'Search',
component: Search,
icon: searchIcon,
},
];
export const MainTabNavigator = () => {
return (
<Tab.Navigator tabBarOptions={{ style: { height: Platform.OS === 'ios' ? 90 : 50 } }}>
{tabData.map((item, idx) => (
<Tab.Screen
key={`tab_item${idx + 1}`}
name={item.name}
component={item.component}
options={{
tabBarIcon: ({ focused }) => (
<View style={styles.tabBarItemContainer}>
<Image
resizeMode="contain"
source={item.icon}
style={[styles.tabBarIcon, focused && styles.tabBarIconFocused]}
/>
</View>
),
tabBarLabel: ({ focused }) => <Text style={{ fontSize: 12, color: focused ? colors.primary : colors.gray }}>{item.name}</Text>,
title: item.name,
}}
/>
))}
</Tab.Navigator>
);
};
const styles = StyleSheet.create({
tabBarItemContainer: {
alignItems: 'center',
justifyContent: 'center',
borderBottomWidth: 2,
borderBottomColor: colors.white,
paddingHorizontal: 10,
bottom: Platform.OS === 'ios' ? -5 : 0,
},
tabBarIcon: {
width: 23,
height: 23,
},
tabBarIconFocused: {
tintColor: colors.primary,
},
});
DashboardView.js
import React , {useContext }from 'react';
import { StyleSheet, View, TouchableOpacity, Text } from 'react-native';
import {Header} from 'react-native-elements';
import AntIcon from "react-native-vector-icons/AntDesign";
import { colors, fonts } from '../../styles';
import AmountDetails from './AmountDetails';
import DashboardFields from './DashboardFields';
import { AuthContext } from "../authentication/AuthProvider";
import { CommonActions } from "#react-navigation/native";
export default function DashboardView(props) {
const appLogOut = () => {
const { logout } = useContext(AuthContext);
console.log('props', props)
if(logout){
// console.log("Navigation Object", navigation)
props.navigation.dispatch(
CommonActions.reset({
index: 0,
routes: [{ name: "AuthNavigator" }],
}));
}
}
return (
<View style={styles.container}>
<Header containerStyle = {{backgroundColor: colors.primary}}
centerComponent={{ text: 'Dashboard', style: { color: colors.white, backgroundColor: colors.primary } }}
rightComponent = <TouchableOpacity onPress={appLogOut()}><AntIcon name="logout" color="white" size={25}/></TouchableOpacity>
/>
<View style={styles.container}>
<View>
<AmountDetails />
</View>
<View style={styles.dashboardFields}>
<DashboardFields />
</View>
</View>
</View>
);
}
const styles = StyleSheet.create({
container: {
flex: 1,
backgroundColor: colors.gray,
},
dashboardFields: {
marginTop: 20,
},
});
You should try calling the login screen directly, not the whole stack.
CommonActions.reset({
index: 0,
routes: [{ name: "Login" }],
}));
As the other answer said, you have incorrect route name (AuthNavigator).
However, you're conditionally defining screens based on if the user is logged in. You don't need to do anything extra when logging out. Conditionally defining screens means React Navigation can automatically handle which screen to show when the conditional changes.
So you need to remove the code which does reset.
From the docs:
It's important to note that when using such a setup, you don't need to manually navigate to the Home screen by calling navigation.navigate('Home') or any other method. React Navigation will automatically navigate to the correct screen when isSigned in changes - Home screen when isSignedIn becomes true, and to SignIn screen when isSignedIn becomes false. You'll get an error if you attempt to navigate manually.
More details: https://reactnavigation.org/docs/auth-flow/
I was trying to put an Switch and an Icon on header created with stack navigation from react navigation. the problem I am facing is that adjusting the switch and icon accordingly next to each other. I tried different alternatives but still I am unable to adjust them. I wanted to show on the header a text in the center; Home for instance, and show also a switch and icon on the right of the header next to each other (switch and icon). I will highly appreciate any help of how Can I do this? Here I am sharing my code trying to do it.
/**
* Sample React Native App
* https://github.com/facebook/react-native
*
* #format
* #flow strict-local
*/
import React, {useState} from 'react';
import {StatusBar, View, TouchableOpacity} from 'react-native';
import {
NavigationContainer,
DarkTheme as navigationDarkTheme,
DefaultTheme as navigationDefaultTheme,
useTheme
} from '#react-navigation/native';
import {createStackNavigator} from '#react-navigation/stack';
import {
DarkTheme as PaperDarkTheme,
Provider as PaperProvider,
DefaultTheme as PaperDefaultTheme,
Text,
Title,
TouchableRipple,
Switch,
} from 'react-native-paper';
import MaterialCommunityIcons from 'react-native-vector-icons/MaterialCommunityIcons';
const customDarktheme = {
...PaperDarkTheme,
...navigationDarkTheme,
colors: {
...PaperDarkTheme.colors,
...navigationDarkTheme.colors,
headerColor: 'rgb(255, 255, 255)',
bgcolor: "#404040",
surface:"#404040",
btnSearchColor:"#404040",
}
}
const customDefaulttheme = {
...PaperDefaultTheme,
...navigationDefaultTheme,
colors: {
...PaperDefaultTheme.colors,
...navigationDefaultTheme.colors,
headerColor: "white",
bgcolor: "#fafcff",
btnSearchColor:"#006aff",
surface:"white",
}
}
const HomeS = () => {
return <View></View>;
};
const Stack = createStackNavigator();
const App = () => {
const {colors} = useTheme()
const [isDarktheme, setDarkTheme] = useState(false);
const togglemethod = () => {
setDarkTheme(!isDarktheme);
};
return (
<>
<PaperProvider theme={isDarktheme?customDarktheme:customDefaulttheme}>
<NavigationContainer theme={isDarktheme?customDarktheme:customDefaulttheme}>
<StatusBar barStyle="dark-content" />
<Stack.Navigator screenOptions={{headerTitleAlign: 'center', headerStyle: { backgroundColor: colors.headerColor }}}>
<Stack.Screen
name="Home"
component={HomeS}
options={{
headerTitle: (props) => (
<View style={{flexDirection: 'row', width:"300%"}}>
<>
<View>
<Title style={{paddingLeft: 180}}>
<Text>Home</Text>
</Title>
</View>
<View >
<TouchableRipple rippleColor="rgba(0, 0, 0, .32)">
<Switch
value={isDarktheme}
color="yellow"
onValueChange={() => togglemethod()}
style={{
paddingLeft:250,
}}
/>
</TouchableRipple>
</View>
<View style={{}}>
<MaterialCommunityIcons
name={
isDarktheme
? 'moon-waning-crescent'
: 'white-balance-sunny'
}
size={25}
color={isDarktheme ? "yellow" : "blue"}
style={{
paddingLeft: 110,
// paddingBottom: 5,
width: '200%',
flexDirection: 'row',
paddingRight:300
}}
/>
</View>
</>
</View>
),
}}
/>
</Stack.Navigator>
</NavigationContainer>
</PaperProvider>
</>
);
};
export default App;
currently the header looks like this:
look at the distance b/w the switch and Icon. trying to eliminate this was not possible for me. for example the text Home disappears while adjusting other elements like switch or Icon. I know this can be achieved. but I run out of options and glad that someone else can do it and learn from.
Since you want to add the switch and icon on the right, you should use headerRight instead of headerTitle
options={{
headerRight: () => (
<View style={{ flexDirection: 'row', justifyContent: 'flex-end' }}>
// Your switch and icon here
</View>
),
}}
I am trying to set a gradient color for android status bar using react-native. But setBackgroundColor is taking color string.
Is it possible to use gradient color for status bar color?
You can use translucent={true} and backgroundColor={'transparent'} properties with StatusBar and wrap them with react-native-linear-gradient
like this:
<LinearGradient colors={["#79e3fe","#635df8","#42385D"]} style={{flex: 1}}>
<StatusBar translucent={true} backgroundColor={'transparent'} />
</LinearGradient >
You can tweak that.
In my case I use wix/react-native-navigation to navigate between screen in my application. So I use theses options for displaying my screens.
navigatorStyle: {
navBarHidden: true,
statusBarColor: 'transparent',
drawUnderStatusBar: true
},
An after you need to import react-native-linear-gradient to tweak your status bar. (create a component and add it to your pages)
<View>
<LinearGradient colors={yourArrayOfColors} style={styles.header}/>
</View>
... //and in your style
header: {
height: (Platform.OS === 'ios' ? 20 : StatusBar.currentHeight),
}
That could do the trick !
It works out for me with the following steps.
Add React Navigation as root component for React Native.
Create a custom header and make a gradient background for it. react-native-linear-gradient is needed of course. The following code demonstrates how to do it.
// #flow
import React from "react";
import { View, Platform, StatusBar } from "react-native";
import { createStackNavigator, createAppContainer } from "react-navigation";
import { Header, StackViewTransitionConfigs } from "react-navigation";
import LinearGradient from "react-native-linear-gradient";
import MainScreen from "./MainScreen";
const GradientBackground = props => (
<LinearGradient
colors={["#FFD801", "#FF8040"]}
start={{ x: 0, y: 0 }}
end={{ x: 1, y: 0 }}
{...props}
/>
);
const AppNavigator = createStackNavigator(
{
MainScreen: { screen: MainScreen }
},
{
headerBackTitleVisible: false,
initialRouteName: "MainScreen",
defaultNavigationOptions: {
header: props => {
return (
// When StatusBar is translucent, the StatusBar will be offset up by "StatusBar.currentHeight" points.
// That's why the height of the Header is "Header.HEIGHT + StatusBar.currentHeight".
<View style={{ height: Header.HEIGHT + StatusBar.currentHeight }}>
<GradientBackground style={{ height: StatusBar.currentHeight }} />
<Header {...props} />
</View>
);
},
headerTintColor: "#FFF",
headerBackground: (
<GradientBackground style={{ height: Header.HEIGHT }} />
),
headerStyle: {
backgroundColor: "transparent"
}
},
headerLayoutPreset: "center"
}
);
const MainStack = createAppContainer(AppNavigator);
export default MainStack;
Add StatusBar to the root component and set StatusBar translucent.
// #flow
// #format
import React, { Component } from "react";
import { Button, TextInput, StyleSheet, StatusBar } from "react-native";
import { View, Text, FlatList } from "react-native";
import { NavigationScreenProp, NavigationState } from "react-navigation";
type Props = {
navigation: NavigationScreenProp<NavigationState>
};
/**
* 程序主页
* #export MainScreen
* #class MainScreen
* #extends {Component}
*/
export default class MainScreen extends Component<Props> {
static navigationOptions = {
headerTitle: "MainScreen"
};
render() {
const { navigation } = this.props;
return (
<View style={[styles.screenContainer]}>
<StatusBar
barStyle="light-content"
translucent={true}
backgroundColor="transparent"
/>
</View>
);
}
}
const styles = StyleSheet.create({
screenContainer: {
flex: 1
}
});
Enjoy!
If the description above is not clear to you, feel free to download the ReactNavigationGradientStatusbar Project and check it out.
1.add react-native-linear-gradient to your project
use this code :
import {View , StyleSheet,StatusBar} from 'react-native'
import LinearGradient from 'react-native-linear-gradient';
render(){
const StatusBarHeight = StatusBar.currentHeight
return(
<View>
<View style={{ height : StatusBarHeight , width : '100%' }}>
<LinearGradient
start={{x: 0.0, y: 0.5}}
end={{x: 0.5, y: 1.0}}
locations={[0,0.3,0.6]}
colors={['#4c669f', '#3b5998', '#192f6a']} style={style.Container}>
</LinearGradient>
</View>
</View>
)
}
and this :
const style = StyleSheet.create({
Container : {
flex : 1,
backgroundColor : '#2980b9',
justifyContent : 'center',
alignItems : 'center',
flexDirection : 'row'
}
})
As the documentation states at this point it only accepts a string, so no, you cannot. And, besides, I can't even come up with an app using a gradient on their status bar.
If the StatusBar would accept a component you could try using the Expo.io API to do so. Check https://docs.expo.io/versions/latest/sdk/linear-gradient.html if you are curious about it.