Expo LinearGradient

渲染渐变视图的通用 React 组件。

Android

iOS

tvOS

Web

Included in Expo Go

Recommended version:

~57.0.0

expo-linear-gradient 提供一个原生的 React 视图，可以在多个颜色之间以线性方向进行过渡。

信息 React Native 还在 View 组件上提供了 experimental_backgroundImage（Android 和 iOS）和 backgroundImage（Web）样式属性，这些属性支持 CSS 渐变语法，例如 linear-gradient() 和 radial-gradient()。这可以作为不增加额外依赖的渐变背景的替代方案。由于这是一个实验性属性，如果遇到任何问题，请向 React Native 仓库报告。

安装

🌐 Installation

Terminal

- npx expo install expo-linear-gradient

If you are installing this in an existing React Native app, make sure to install expo in your project.

用法

🌐 Usage

Linear Gradient

import { StyleSheet, Text, View } from 'react-native';
import { LinearGradient } from 'expo-linear-gradient';

export default function App() {
  return (
    <View style={styles.container}>
      <LinearGradient
        // Background Linear Gradient
        colors={['rgba(0,0,0,0.8)', 'transparent']}
        style={styles.background}
      />
      <LinearGradient
        // Button Linear Gradient
        colors={['#4c669f', '#3b5998', '#192f6a']}
        style={styles.button}>
        <Text style={styles.text}>Sign in with Facebook</Text>
      </LinearGradient>
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    alignItems: 'center',
    justifyContent: 'center',
    backgroundColor: 'orange',
  },
  background: {
    position: 'absolute',
    left: 0,
    right: 0,
    top: 0,
    height: 300,
  },
  button: {
    padding: 15,
    alignItems: 'center',
    borderRadius: 5,
  },
  text: {
    backgroundColor: 'transparent',
    fontSize: 15,
    color: '#fff',
  },
});

应用接口

🌐 API

import { LinearGradient } from 'expo-linear-gradient';

Component

`LinearGradient`

Type: React.Component<LinearGradientProps>

Renders a native view that transitions between multiple colors in a linear direction.

LinearGradientProps

`colors`

Type: readonly [ColorValue, ColorValue, ...ColorValue[]]

A readonly array of colors that represent stops in the gradient. At least two colors are required (for a single-color background, use the style.backgroundColor prop on a View component).

For TypeScript to know the provided array has 2 or more values, it should be provided "inline" or typed as const.

`dither`

Only for:

Android

Optional • Type: boolean • Default: true

Enables or disables paint dithering. Dithering can reduce the gradient color banding issue. Setting false may improve gradient rendering performance.

`end`

Optional • Literal type: union

For example, { x: 0.1, y: 0.2 } means that the gradient will end 10% from the left and 20% from the bottom.

On web, this only changes the angle of the gradient because CSS gradients don't support changing the end position.

Acceptable values are: LinearGradientPoint | null

`locations`

Optional • Literal type: union • Default: []

A readonly array that contains numbers ranging from 0 to 1, inclusive, and is the same length as the colors property. Each number indicates a color-stop location where each respective color should be located. If not specified, the colors will be distributed evenly across the gradient.

For example, [0.5, 0.8] would render:

the first color, solid, from the beginning of the gradient view to 50% through (the middle);
a gradient from the first color to the second from the 50% point to the 80% point; and
the second color, solid, from the 80% point to the end of the gradient view.

The color-stop locations must be ascending from least to greatest.

Acceptable values are: readonly [number, number, ...number[]] | null

`start`

Optional • Literal type: union

For example, { x: 0.1, y: 0.2 } means that the gradient will start 10% from the left and 20% from the top.

On web, this only changes the angle of the gradient because CSS gradients don't support changing the starting position.

Acceptable values are: LinearGradientPoint | null

Inherited Props

ViewProps

Types

`LinearGradientPoint`

An object { x: number; y: number } or array [x, y] that represents the point at which the gradient starts or ends, as a fraction of the overall size of the gradient ranging from 0 to 1, inclusive.

Type: NativeLinearGradientPoint or object shaped as below:

Property	Type	Description
x	`number`	A number ranging from `0` to `1`, representing the position of gradient transformation.
y	`number`	A number ranging from `0` to `1`, representing the position of gradient transformation.

`NativeLinearGradientPoint`

Tuple: [x: number, y: number]