如何从Express后端服务器到React JS前端获取和显示图像? [英] How to Fetch and Display an Image from an express backend server to a React js frontend?

问题描述

我正在尝试从快速后端获取图像并将其显示在react js前端中.我怎样才能完美地做到这一点?

I'm trying to fetch images from an express backend and display them in the react js frontend. How can I achieve this perfectly?

我试图获取保存在名为"Backup"的后端文件夹中的图像，并在react js前端中将它们显示回给用户.我已经使用axios尝试了此操作，但仍然收到无效的图像，而不是正确的图像.

I have tried to fetch the images saved in my backend folder named "Backup" and display them back to the user in the react js frontend. I have tried this using axios but still am getting an invalid image instead of the correct image.

下面是我在前端的提取请求.

Below is my fetch request in the frontend.

fetchImages = () => {
    const imageName = 'garande.png'
    const url = `http://localhost:5000/fetchImage/${imageName}`
    axios.get(url, {responseType: 'blob'})
    .then(res => {
        return(
            <img src={res.data} alt="trial" />
        )
    }
}

这就是我后端的server.js文件中的内容

And this what I have in the server.js file in the backend

app.get('/fetchImage/:file(*)', (req, res) => {
    let file = req.params.file;
    let fileLocation = path.join('../Backup/images/', file);
    //res.send({image: fileLocation});
    res.sendFile(`${fileLocation}`)
})

我希望该图片显示在用户页面中.谢谢.

I expect the Image to show up in the users page. Thanks.

推荐答案

这对我有用:

export async function get(url: string) {
    try {
        const response = await fetch(url, {
            method: 'GET', // *GET, POST, PUT, DELETE, etc.
            mode: 'cors', // no-cors, *cors, same-origin
            cache: 'no-cache', // *default, no-cache, reload, force-cache, only-if-cached
            headers: {
                'Content-Type': 'image/jpeg'
            }
        })
        const blob = await response.blob()
        return [URL.createObjectURL(blob), null];
    }
    catch (error) {
        console.error(`get: error occurred ${error}`);
        return [null, error]
    }
}   

function foo(props: any) {
const [screenShot, setScreenshot] = useState(undefined)
const url = props.url
useEffect(() => {
    async function fetchData() {
        // You can await here
        const [response, error] = await get(url)
        if (error)
            log(error)
        else {
            log(`got response ${response}`)
        setScreenshot(response)
        }
    }
    fetchData();
}, [url])

return <div>
    <img src={screenShot} className="Screenshot" alt="showing screen capture" />
</div>
}

这篇关于如何从Express后端服务器到React JS前端获取和显示图像?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！