1、package.json修改

build:mp-xxxxx": "cross-env NODE_ENV=xxxxxxx UNI_OUTPUT_DIR=dist/build/mp-weixin UNI_PLATFORM=mp-weixin vue-cli-service uni-build"

2、和manifest文件同目录新建modifyManifest.js文件

const fs = require('fs');

const manifestPath = process.env.UNI_INPUT_DIR + '/manifest.json'
let Manifest = fs.readFileSync(manifestPath, {
	encoding: 'utf-8'
})

function replaceManifest(path, value) {
	const arr = path.split('.')
	const len = arr.length
	const lastItem = arr[len - 1]

	let i = 0
	let ManifestArr = Manifest.split(/\n/)

	for (let index = 0; index < ManifestArr.length; index++) {
		const item = ManifestArr[index]
		if (new RegExp(`"${arr[i]}"`).test(item)) ++i;
		if (i === len) {
			const hasComma = /,/.test(item)
			ManifestArr[index] = item.replace(new RegExp(`"${lastItem}"[\\s\\S]*:[\\s\\S]*`),
				`"${lastItem}": ${value}${hasComma ? ',' : ''}`)
			break;
		}
	}

	Manifest = ManifestArr.join('\n')
}
console.log(process.env.NODE_ENV)
// 动态配置 appid。下面要修改的appid必须死后单引号包双引号
if (process.env.NODE_ENV == 'xxxxxxxxx') {
	replaceManifest('mp-weixin.appid', '"需要修改的appid"')
} else {
	replaceManifest('mp-weixin.appid', '"需要修改的appid""')
}

fs.writeFileSync(manifestPath, Manifest, {
	"flag": "w"
})

4、vue.config.js中引入 modifyManifest

require('./src/modifyManifest')