uniapp实现移动端签名板功能完整代码，导入即可使用

function getLocalFilePath(path) { if (path.indexOf('_www') === 0 || path.indexOf('_doc') === 0 || path.indexOf('_documents') === 0 || path.indexOf('_downloads') === 0) { return path } if (path.indexOf('file://') === 0) { return path } if (path.indexOf('/storage/emulated/0/') === 0) { return path } if (path.indexOf('/') === 0) { var localFilePath = plus.io.convertAbsoluteFileSystem(path) if (localFilePath !== path) { return localFilePath } else { path = path.substr(1) } } return '_www/' + path } function dataUrlToBase64(str) { var array = str.split(',') return array[array.length - 1] } var index = 0 function getNewFileId() { return Date.now() + String(index++) } function biggerThan(v1, v2) { var v1Array = v1.split('.') var v2Array = v2.split('.') var update = false for (var index = 0; index < v2Array.length; index++) { var diff = v1Array[index] - v2Array[index] if (diff !== 0) { update = diff > 0 break } } return update } export function pathToBase64(path) { return new Promise(function(resolve, reject) { if (typeof window === 'object' && 'document' in window) { if (typeof FileReader === 'function') { var 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 } var canvas = document.createElement('canvas') var c2x = canvas.getContext('2d') var 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') { plus.io.resolveLocalFileSystemURL(getLocalFilePath(path), function(entry) { entry.file(function(file) { var fileReader = new plus.io.FileReader() fileReader.onload = function(data) { resolve(data.target.result) } fileReader.onerror = function(error) { reject(error) } fileReader.readAsDataURL(file) }, function(error) { reject(error) }) }, function(error) { reject(error) }) return } if (typeof wx === 'object' && wx.canIUse('getFileSystemManager')) { wx.getFileSystemManager().readFile({ filePath: path, encoding: 'base64', success: function(res) { resolve('data:image/png;base64,' + res.data) }, fail: function(error) { reject(error) } }) return } reject(new Error('not support')) }) } export function base64ToPath(base64) { return new Promise(function(resolve, reject) { if (typeof window === 'object' && 'document' in window) { base64 = base64.split(',') var type = base64[0].match(/:(.*?);/)[1] var str = atob(base64[1]) var n = str.length var array = new Uint8Array(n) while (n--) { array[n] = str.charCodeAt(n) } return resolve((window.URL || window.webkitURL).createObjectURL(new Blob([array], { type: type }))) } var extName = base64.split(',')[0].match(/data\:\S+\/(\S+);/) if (extName) { extName = extName[1] } else { reject(new Error('base64 error')) } var fileName = getNewFileId() + '.' + extName if (typeof plus === 'object') { var basePath = '_doc' var dirPath = 'uniapp_temp' var filePath = basePath + '/' + dirPath + '/' + fileName if (!biggerThan(plus.os.name === 'Android' ? '1.9.9.80627' : '1.9.9.80472', plus.runtime.innerVersion)) { plus.io.resolveLocalFileSystemURL(basePath, function(entry) { entry.getDirectory(dirPath, { create: true, exclusive: false, }, function(entry) { entry.getFile(fileName, { create: true, exclusive: false, }, function(entry) { entry.createWriter(function(writer) { writer.onwrite = function() { resolve(filePath) } writer.onerror = reject writer.seek(0) writer.writeAsBinary(dataUrlToBase64(base64)) }, reject) }, reject) }, reject) }, reject) return } var bitmap = new plus.nativeObj.Bitmap(fileName) bitmap.loadBase64Data(base64, function() { bitmap.save(filePath, {}, function() { bitmap.clear() resolve(filePath) }, function(error) { bitmap.clear() reject(error) }) }, function(error) { bitmap.clear() reject(error) }) return } if (typeof wx === 'object' && wx.canIUse('getFileSystemManager')) { var filePath = wx.env.USER_DATA_PATH + '/' + fileName wx.getFileSystemManager().writeFile({ filePath: filePath, data: dataUrlToBase64(base64), encoding: 'base64', success: function() { resolve(filePath) }, fail: function(error) { reject(error) } }) return } reject(new Error('not support')) }) }