Category: React

Sometimes, we want to make an item stick to the bottom using flex in React Native.

In this article, we’ll look at how to make an item stick to the bottom using flex in React Native.

How to make an item stick to the bottom using flex in React Native?

To make an item stick to the bottom using flex in React Native, we can set the flex style property.

For instance, we write:

import * as React from 'react';
import { Text, View, TextInput } from 'react-native';
import Constants from 'expo-constants';
import AssetExample from './components/AssetExample';
import { Card } from 'react-native-paper';
import { Icon } from 'react-native-elements';

export default function App() {
  return (
    <View style={{ flex: 1 }}>
      <View style={{ flex: 1 }}>
        <Text>hello</Text>
      </View>
      <View style={{ flex: 0 }}>
        <Text>world</Text>
      </View>
    </View>
  );
}

to set the style prop of the outer and the first inner div to an object with the flex property set to 1 to stretch the views.

The outer view is stretched to fit the screen.

And the first inner view is stretch to fit the space between the top of the screen and the footer view.

Therefore, we see ‘world’ displayed at the bottom of the screen.

Conclusion

To make an item stick to the bottom using flex in React Native, we can set the flex style property.

Sometimes, we want to put an icon inside a TextInput in React Native.

In this article, we’ll look at how to put an icon inside a TextInput in React Native.

How to put an icon inside a TextInput in React Native?

To put an icon inside a TextInput in React Native, we can put an Icon and a TextInput in the same View.

For instance, we write:

import * as React from 'react';
import { Text, View, TextInput } from 'react-native';
import Constants from 'expo-constants';
import AssetExample from './components/AssetExample';
import { Card } from 'react-native-paper';
import { Icon } from 'react-native-elements';

export default function App() {
  return (
    <View style={{ flexDirection: 'row', gap: 5, alignItems: 'center' }}>
      <Icon name="ios-search" size={20} color="#000" />
      <TextInput
        placeholder="User Nickname"
        onChangeText={(searchString) => console.log(searchString)}
        underlineColorAndroid="transparent"
      />
    </View>
  );
}

to add a View that has flexDirection set to 'row' to let us add the Icon and TextInput side by side.

Then we add the Icon to the left of the TextInput.

Conclusion

To put an icon inside a TextInput in React Native, we can put an Icon and a TextInput in the same View.

Sometimes, we want to get the current value of Animated.Value with React Native.

In this article, we’ll look at how to get the current value of Animated.Value with React Native.

How to get the current value of Animated.Value with React Native?

To get the current value of Animated.Value with React Native, we call addListener on the animated value object.

For instance, we write:

import * as React from 'react';
import { View, Animated, Text, Easing } from 'react-native';
import Constants from 'expo-constants';
import { Card } from 'react-native-paper';

const spinValue = new Animated.Value(0);

export default function App() {
  React.useEffect(() => {
    spinValue.addListener(({ value }) => console.log(value));
    Animated.timing(spinValue, {
      toValue: 1,
      duration: 3000,
      easing: Easing.linear,
      useNativeDriver: true,
    }).start();
  }, []);

  const spin = spinValue.interpolate({
    inputRange: [0, 1],
    outputRange: ['0deg', '360deg'],
  });

  return (
    <Animated.Image
      style={{ transform: [{ rotate: spin }], width: 200, height: 300 }}
      source={{ uri: 'https://picsum.photos/200/300' }}
    />
  );
}

to call spinValue.addListener with a callback to get the current value of the animated value from the value property.

We create an animated value with Animated.Value and call Animated.timing to create the animation.

Then we call start to start the animation.

As a result, we should see the value logged as the animation is being run.

Conclusion

To get the current value of Animated.Value with React Native, we call addListener on the animated value object.

Sometimes, we want to animate the rotation of an Image with React Native.

In this article, we’ll look at how to animate the rotation of an Image with React Native.

How to animate the rotation of an Image with React Native?

To animate the rotation of an Image with React Native, we can use the animated value’s interpolate method.

For instance, we write:

import * as React from 'react';
import { View, Animated, Text, Easing } from 'react-native';
import Constants from 'expo-constants';
import { Card } from 'react-native-paper';

const spinValue = new Animated.Value(0);

export default function App() {
  React.useEffect(() => {
    Animated.timing(spinValue, {
      toValue: 1,
      duration: 3000,
      easing: Easing.linear,
      useNativeDriver: true,
    }).start();
  }, []);

  const spin = spinValue.interpolate({
    inputRange: [0, 1],
    outputRange: ['0deg', '360deg'],
  });

  return (
    <Animated.Image
      style={{ transform: [{ rotate: spin }], width: 200, height: 300 }}
      source={{ uri: 'https://picsum.photos/200/300' }}
    />
  );
}

to add the Animated.Image component to add an image that can animate.

Then we define the spinValue animated value with Animated.Value.

Next, we call Animated.timing with spinValue and some options for the animation.

toValue is the value of the inputValue to animate to.

duration is the duration of the animation in milliseconds.

easing is the easing.

Next, we call spinValue.interpolate to interpolate the animation values.

We call start to start the animation in the useEffect callback.

Conclusion

To animate the rotation of an Image with React Native, we can use the animated value’s interpolate method.

Sometimes, we want to animate backgroundColor in React Native.

In this article, we’ll look at how to animate backgroundColor in React Native.

How to animate backgroundColor in React Native?

To animate backgroundColor in React Native, we can use the animated value’s interpolate method.

For instance, we write:

import * as React from 'react';
import { View, Animated, Text } from 'react-native';
import Constants from 'expo-constants';
import { Card } from 'react-native-paper';

const c = new Animated.Value(0);

export default function App() {
  React.useEffect(() => {
    Animated.timing(c, {
      toValue: 300,
      duration: 3000,
    }).start();
  }, []);

  const color = c.interpolate({
    inputRange: [0, 200, 300],
    outputRange: ['orange', 'lightgreen', 'yellow'],
  });

  return (
    <Animated.View style={{ backgroundColor: color }}>
      <Text>hello world</Text>
    </Animated.View>
  );
}

to create a new animated value with Animated.Value.

Then we call Animated.timing to create the animation.

We specify the toValue to animate to the value of the inputRange we specify.

And we specify the duration of the animation in milliseconds.

Finally, we specify the color values to animate in the outputRange and set the color as the value of the backgroundColor.

As a result, we should see the color change for 3 seconds when the page loads.

Conclusion

To animate backgroundColor in React Native, we can use the animated value’s interpolate method.