前端 react 实现图片上传前压缩(缩率图)-牛翰网

一、安装

npm install compressorjs
或
yarn add compressorjs

官方文档：compressorjs – npm (npmjs.com)

二、编写工具类

/**
 * @author Dragon Wu
 * @since 2024/8/4 12:23
 * 图片压缩工具
 */
import Compressor from 'compressorjs';
// 压缩图片方法 （中间件）
export function compressor(file: File, defaultQuality: number = 0.6) {
    // console.log('压缩前: ', (file.size / 1024 / 1024).toFixed(1), 'M');//控制台打印图片大小
    const filesize: number = parseFloat((file.size / 1024 / 1024).toFixed(1));
    let quality = defaultQuality;
    if (filesize < 0.8) { //这里可以设置自己的压缩规则
        quality = 1;
    } else if (filesize < 1) {
        quality = 0.8;
    } else if (filesize < 1.5) {
        quality = 0.7;
    } else if (filesize < 2) {
        quality = 0.5;
    } else if (filesize < 3) {
        quality = 0.33;
    } else if (filesize < 4) {
        quality = 0.25;
    } else if (filesize < 5) {
        quality = 0.2;
    } else if (filesize < 8) {
        quality = 0.125;
    } else if (filesize < 10) {
        quality = 0.1;
    } else {
        return new Promise((resolve, reject) => {
            reject({
                msg: '图片不能超过10M'
            })
        });
    }
    // console.log('压缩比例: ', quality);
    return new Promise((resolve) => {
        new Compressor(file, {
            quality: quality,
            success(result: File | Blob) {
                // console.log('压缩后: ', (result.size / 1024 / 1024).toFixed(1), 'M');
                if (result instanceof Blob) {
                    //@ts-ignore
                    result = new File([result], "f" + (result?.name as string).slice(-8), {type: result.type})
                }
                resolve(result);
            },
            error(err) {
                // 压缩报错的话 返回原图片
                resolve(file);
            },
        });
    });
}

三、获取压缩后的File对象

const handleBeforeUpload = (file: FileType) => {
        const isJpgOrPng = file.type === 'image/jpeg' || file.type === 'image/png';
        if (!isJpgOrPng) {
            message.warning('只能上传JPG/PNG格式!').then();
        }
        const isLt2M = file.size / 1024 / 1024 < 10;
        if (!isLt2M) {
            message.warning('图片不得超过10MB!').then();
        }
        compressor(file).then(res => {
            if (isJpgOrPng && isLt2M) {
                onChange(res)
            }
        })
        return false;
    }