var imgBaseData = '你的base64图片'; const fsm = wx.getFileSystemManager(); const FILE_BASE_NAME = 'tmp_base64src'; let pro2 = new Promise((resolve, reject) => {     const [, format, bodyData] = /data:image\/(\w+);base64,(.*)/.exec(imgBaseData) || [];     if (!format) {         reject(new Error('ERROR_BASE64SRC_PARSE'));     }     const filePath = `${wx.env.USER_DATA_PATH}/${FILE_BASE_NAME}.${format}`;     const buffer = wx.base64ToArrayBuffer(bodyData);     fsm.writeFile({         filePath,         data: buffer,         encoding: 'binary',         success() {             resolve(filePath);         },         fail() {             reject(new Error('ERROR_BASE64SRC_WRITE'));         },     }); }); pro2.then(data =>{     console.log(data);     //画图     canvas.drawImage(data, 0, 0, 300, 300) //data即是图片路径 })