如何在样式化组件中访问 Material-ui 的主题

Question

我将 CRA 与 Material-ui 和 Styled Components 类型的样式一起使用。 在构建我的 CSS 时，我想访问 Material-ui 的默认主题。

package.json 的一部分：

  "dependencies": {
    "react": "^16.8.6",
    "react-dom": "^16.8.6",
    "react-scripts": "3.0.1",
    "@material-ui/core": "^4.2.1",
    "@material-ui/icons": "^4.2.1",
    "@material-ui/styles": "^4.2.1",
    "styled-components": "^4.3.2"
  }

当我尝试下面的theme 时，props 上存在但它是一个空对象。

StyledApp.js：

import styled from "styled-components";
import Button from "@material-ui/core/Button";

export const StyledButtonUsingTheme = styled(Button)`
  //Below will give "Cannot read property 'error' of undefined" 
  background-color: ${props => props.theme.palette.error.light};
`;

App.js：

import React from "react";
import "./App.css";

import { StylesProvider, ThemeProvider } from "@material-ui/styles";
import { createMuiTheme } from "@material-ui/core/styles";

import { StyledButtonUsingTheme } from "./StyledApp";

function App() {
  const defaultTheme = createMuiTheme();

  window.console.log("Default theme passing to ThemeProvider", defaultTheme);

  return (
    <StylesProvider injectFirst>
      <ThemeProvider theme={defaultTheme}>
        <div className="App">
          <StyledButtonUsingTheme variant="outlined">
            Styled Button Using Theme
          </StyledButtonUsingTheme>
        </div>
      </ThemeProvider>
    </StylesProvider>
  );
}

export default App;

App.js 中的 console.log 显示了整个主题对象，这就是我传递给 ThemesProvider 的内容。有趣的是props.theme 在那里！但遗憾的是没有价值。

Answer 1

您可以使用 withTheme ：

App.js

import React from "react"
import { ThemeProvider, createMuiTheme } from "@material-ui/core/styles"
import { StyledButton } from "./StyledButton"

const App = () => {

    const theme = createMuiTheme();

    return (
        <ThemeProvider theme={theme}>
            <StyledButton />
        </ThemeProvider>
    )
}

export default App

StyledButton.js

import { styled, withTheme } from "@material-ui/core/styles"
import Button from "@material-ui/core/Button"

export const StyledButton= styled(withTheme(Button))(props => ({
  background: props.theme.palette.background.paper,
}))

Answer 2

正如 Horyd 在评论中所说，使用 Styled-Components 中的 ThemeProvider 将使您能够访问样式化组件中的主题属性。 但是 Material-UI 不再将该主题应用到它自己的组件中。

我发现的解决方法既丑陋又简单：同时使用 Themeproviders。因此 Material-UI 将主题应用于其组件，您可以在样式化的组件中访问主题。

import { ThemeProvider } from "styled-components";
import { MuiThemeProvider,StylesProvider } from "@material-ui/core/styles";

ReactDOM.render(

  //Make sure the Material stylesheet is placed above your own 
  //styles so you can overwrite them
  <StylesProvider injectFirst> 

    //Use the theme in the ThemeProvider for Material-UI so
    //styles are applied to the Material-UI components
    <MuiThemeProvider theme={theme}>

      //Use also the ThemeProvider for Styled-Components so 
      //you can access the theme in your own css
      <ThemeProvider theme={theme}>

        //Include your app and you have acces to everything 
        <App />

      </ThemeProvider>

    </MuiThemeProvider>

  </StylesProvider>,

document.getElementById("app"));

Answer 3

withTheme 使用的答案几乎是完整的。最后一部分对我不起作用，所以我改为：

import styled from 'styled-components'
import { withTheme } from "@material-ui/core/styles"

const StyledButton = withTheme(styled('h1')`
    background-color: ${props => props.theme.palette.error.light};
  `
)

Answer 4

问题解决了！

解决方案是使用： import { ThemeProvider } from "styled-components"; 在 App.js 中，然后 theme 包含 props 对象上的所有值。

我在 App.js 中使用了来自“@material-ui/styles”的 ThemeProvider import { StylesProvider, ThemeProvider } from "@material-ui/styles"; 这与 StyledApp.js 中的 `import styled from "styled-components" 效果不佳

工作的两个文件：

App.js

import React from "react";
import "./App.css";

import { StylesProvider } from "@material-ui/styles";
import { ThemeProvider } from "styled-components";
import { createMuiTheme } from "@material-ui/core/styles";

import { StyledButtonUsingTheme } from "./StyledApp";

function App() {
  const defaultTheme = createMuiTheme();

  window.console.log("Default theme passing to ThemeProvider", defaultTheme);

  return (
    <StylesProvider injectFirst>
      <ThemeProvider theme={defaultTheme}>
        <div className="App">
          <StyledButtonUsingTheme variant="outlined">
            Styled Button Using Theme
          </StyledButtonUsingTheme>
        </div>
      </ThemeProvider>
    </StylesProvider>
  );
}

export default App;

StyledApp.js

import styled from "styled-components";
import Button from "@material-ui/core/Button";

export const StyledButtonUsingTheme = styled(Button)`
  //Below will work now!
  background-color: ${props => props.theme.palette.error.light};
`;

Answer 5

如果您想同时使用 ThemeProviders，首先来自 styled-components，其次来自 material-ui，您可以为其中一个使用 alias：

import { ThemeProvider as StyledThemeProvider} from 'styled-components';
import { ThemeProvider } from '@material-ui/core/styles';

 function App() {
  return (
    <Router>
      <ThemeProvider theme={theme}>
      <StyledThemeProvider theme={theme}>
        <Wrapper>
          <TheHeader />
          <TheContent />
          <TheFooter />
        </Wrapper>
      </StyledThemeProvider>
      </ThemeProvider>
    </Router >
  );
}

export default App;

Answer 6

在我的例子中，我发现theme对象是自动与styled component一起传入的，可以通过如下参数访问：

import React from 'react';
import { styled } from '@material-ui/core';

const StyledButton = styled('button')(({ theme }) => ({
    color: theme.palette.text.secondary,
}));

我在 MUI v4.11.0 中有这个工作。

Answer 7

在您的样式组件中，您可以使用钩子 useTheme 示例：

import { useTheme } from "@material-ui/core"
import { styled } from "@material-ui/styles"

const theme = useTheme

  const StyledListbox = styled("ul")({
    backgroundColor: theme.palette.primary.main,
  })