我正在用Electron-vue进行开发。我想逐行读取用户提供的大文本文件。另外,我想在阅读过程中显示一个加载图标(这意味着阅读应该是异步的)。
请注意,该文本文件使用shift-jis编码。
起初,我尝试了以下方法:
src / renderer / components / Import.vue
const dialog = require('electron').remote.dialog
export default {
name: 'import',
data () {
return {
loading: false
}
},
methods: {
mounted () {
this.$refs.search.focus()
},
openDialog () {
let filePath = dialog.showOpenDialog({
properties: ['openFile'],
})
this.loading = true
let that = this
// Use the async function.
this.getResultFileRead(that, filePath[0]).then(function (res) {
// When the async function is completed, remove the loading icon.
that.loading = false
console.log(res)
})
},
// Define async function here.
async getResultFileRead (path) {
return this.$electron.ipcRenderer.sendSync('readfile', path)
}
}
}
src / main / index.js
import fs from 'fs'
import readline from 'readline'
import iconv from 'iconv-lite'
ipcMain.on('readfile', (event, arg) => {
// Using stream to decode shift-jis file.
stream = fs.createReadStream(filePath).pipe(iconv.decodeStream('shift-jis'))
let reader = readline.createInterface(stream, {})
reader.on('line', line => {
insertLine(line)
})
reader.on('close', () => {
// do other stuff
})
event.returnValue = 'complete'
})
但是这些没有用。提供文件时,将以异步方式读取文件,但是只要提供了文件(即在完成操作之前),readfile函数就会返回“ complete”,因此加载图标永远不会出现。
如何在Electron-Vue上实现“异步读取带有shift-jis的文件”和“读取文件时显示加载图标”两者? 请注意,Electron-vue似乎使用的是Node.js版本8.9.3。
答案 0 :(得分:0)
我如下解决了这个问题。
src / main / index.js
import fs from 'fs'
import readline from 'readline'
import iconv from 'iconv-lite'
ipcMain.on('readfile', async (event, arg) => {
await readLines()
event.sender.send('readfile-reply', 'complete')
})
function readLines() {
return new Promise((resolve, reject) => {
stream = fs.createReadStream(filePath).pipe(iconv.decodeStream('shift-jis'))
let reader = readline.createInterface(stream, {})
reader
.on('line', line => {
insertLine(line)
})
.on('close', () => {
resolve() // "Resolve" in the close event.
})
.on('error', function(err) {
reject(err)
})
})
}
然后该函数可以异步使用:
src / renderer / components / Import.vue
const dialog = require('electron').remote.dialog
export default {
name: 'import',
data() {
return {
loading: false
}
},
methods: {
mounted() {
this.$refs.search.focus()
},
openDialog() {
let filePath = dialog.showOpenDialog({
properties: ['openFile'],
})
this.loading = true
let that = this
// Use the async function.
this.asyncReadFile(that, filePath[0]).then(function(res) {
// When the async function is completed, remove the loading icon.
that.loading = false
console.log(res)
})
},
asyncReadFile(that, path) {
return new Promise(resolve => {
this.$electron.ipcRenderer.send('readfile', path)
this.$electron.ipcRenderer.on('readfile-reply', (event, result) => {
resolve(result)
})
})
}
}
}