// 图像转换工具,可用于图像和base64的转换 // https://ext.dcloud.net.cn/plugin?id=123 const getLocalFilePath = (path) => { if ( path.indexOf('_www') === 0 || path.indexOf('_doc') === 0 || path.indexOf('_documents') === 0 || path.indexOf('_downloads') === 0 ) return path if (path.indexOf('/storage/emulated/0/') === 0) return path if (path.indexOf('/storage/sdcard0/') === 0) return path if (path.indexOf('/var/mobile/') === 0) return path if (path.indexOf('file://') === 0) return path if (path.indexOf('/') === 0) { // ios 无法获取本地路径 let localFilePath = plus.os.name === 'iOS' ? path : plus.io.convertLocalFileSystemURL(path) if (localFilePath !== path) { return localFilePath } else { path = path.substring(1) } } return '_www/' + path } export const pathToBase64 = (path) => { return new Promise((resolve, reject) => { if (typeof window === 'object' && 'document' in window) { if (typeof FileReader === 'function') { let xhr = new XMLHttpRequest() xhr.open('GET', path, true) xhr.responseType = 'blob' xhr.onload = function() { if (this.status === 200) { let fileReader = new FileReader() fileReader.onload = function(e) { resolve(e.target.result) } fileReader.onerror = reject fileReader.readAsDataURL(this.response) } } xhr.onerror = reject xhr.send() return } let canvas = document.createElement('canvas') let c2x = canvas.getContext('2d') let img = new Image img.onload = function() { canvas.width = img.width canvas.height = img.height c2x.drawImage(img, 0, 0) resolve(canvas.toDataURL()) canvas.height = canvas.width = 0 } img.onerror = reject img.src = path return } if (typeof plus === 'object') { let tempPath = getLocalFilePath(path) plus.io.resolveLocalFileSystemURL(tempPath, (entry) => { entry.file((file) => { let fileReader = new plus.io.FileReader() fileReader.onload = function(data) { resolve(data.target.result) } fileReader.onerror = function(error) { console.log(error) reject(error) } fileReader.readAsDataURL(file) }, (error) => { reject(error) }) }, (error) => { reject(error) }) return } if (typeof wx === 'object' && wx.canIUse('getFileSystemManager')) { wx.getFileSystemManager().readFile({ filePath: path, encoding: 'base64', success: (res) => { resolve('data:image/png;base64,' + res.data) }, fail: (error) => { reject(error) } }) return } reject(new Error('not support')) }) } export const base64ToPath = (base64) => { return new Promise((resolve, reject) => { if (typeof window === 'object' && 'document' in window) { base64 = base64.split(',') let type = base64[0].match(/:(.*?);/)[1] let str = atob(base64[1]) let n = str.length let array = new Uint8Array(n) while (n--) { array[n] = str.charCodeAt(n) } return resolve((window.URL || window.webkitURL).createObjectURL(new Blob([array], { type: type }))) } let extName = base64.match(/data\:\S+\/(\S+);/) if (extName) { extName = extName[1] } else { reject(new Error('base64 error')) } let fileName = Date.now() + '.' + extName if (typeof plus === 'object') { let bitmap = new plus.nativeObj.Bitmap('bitmap' + Date.now()) bitmap.loadBase64Data(base64, () => { let filePath = '_doc/uniapp_temp/' + fileName bitmap.save(filePath, {}, () => { bitmap.clear() resolve(filePath) }, (error) => { bitmap.clear() reject(error) }) }, (error) => { bitmap.clear() reject(error) }) return } if (typeof wx === 'object' && wx.canIUse('getFileSystemManager')) { let filePath = wx.env.USER_DATA_PATH + '/' + fileName wx.getFileSystemManager().writeFile({ filePath: filePath, data: base64.replace(/^data:\S+\/\S+;base64,/, ''), encoding: 'base64', success: () => { resolve(filePath) }, fail: (error) => { reject(error) } }) return } reject(new Error('not support')) }) }