his_user_miniapp/node_modules/cos-wx-sdk-v5/demo/demo-post-policy.js

var config = require('./config');

var uploadFile = function () {

    // 对更多字符编码的 url encode 格式
    var camSafeUrlEncode = function (str) {
        return encodeURIComponent(str)
            .replace(/!/g, '%21')
            .replace(/'/g, '%27')
            .replace(/\(/g, '%28')
            .replace(/\)/g, '%29')
            .replace(/\*/g, '%2A');
    };

    // 获取临时密钥
    var getCredentials = function (options, callback) {
        wx.request({
            method: 'GET',
            url: 'http://127.0.0.1:3000/post-policy?ext=' + options.ext, // 服务端签名，参考 server 目录下的两个签名例子
            dataType: 'json',
            success: function (result) {
                var data = result.data;
                if (data) {
                    callback(data);
                } else {
                    wx.showModal({title: '临时密钥获取失败', content: JSON.stringify(data), showCancel: false});
                }
            },
            error: function (err) {
                wx.showModal({title: '临时密钥获取失败', content: JSON.stringify(err), showCancel: false});
            }
        });
    };

    // 上传文件
    var uploadFile = function (filePath) {
        var extIndex = filePath.lastIndexOf('.');
        var fileExt = extIndex >= -1 ? filePath.substr(extIndex + 1) : '';
        getCredentials({ext: fileExt}, function (credentials) {
            // 请求用到的参数
            // var prefix = 'https://cos.' + config.Region + '.myqcloud.com/' + config.Bucket + '/'; // 这个是后缀式，签名也要指定 Pathname: '/' + config.Bucket + '/'
            var prefix = 'https://' + credentials.bucket + '.cos.' + credentials.region + '.myqcloud.com/';
            var key = credentials.key; // 让服务端来决定文件名更安全
            var formData = {
                'key': key,
                'success_action_status': 200,
                'Content-Type': '',
                'q-sign-algorithm': credentials.qSignAlgorithm,
                'q-ak': credentials.qAk,
                'q-key-time': credentials.qKeyTime,
                'q-signature': credentials.qSignature,
                'policy': credentials.policy,
            };
            if (credentials.securityToken) formData['x-cos-security-token'] = credentials.securityToken;
            var requestTask = wx.uploadFile({
                url: prefix,
                name: 'file',
                filePath: filePath,
                formData: formData,
                success: function (res) {
                    var url = prefix + camSafeUrlEncode(key).replace(/%2F/g, '/');
                    if (res.statusCode === 200) {
                        wx.showModal({title: '上传成功', content: url, showCancel: false});
                    } else {
                        wx.showModal({title: '上传失败', content: JSON.stringify(res), showCancel: false});
                    }
                    console.log(res.header['x-cos-request-id']);
                    console.log(res.statusCode);
                    console.log(url);
                },
                fail: function (res) {
                    wx.showModal({title: '上传失败', content: JSON.stringify(res), showCancel: false});
                }
            });
            requestTask.onProgressUpdate(function (res) {
                console.log('正在进度:', res);
            });
        });
    };

    // 选择文件
    wx.chooseImage({
        count: 1, // 默认9
        sizeType: ['original'], // 可以指定是原图还是压缩图，这里默认用原图
        sourceType: ['album', 'camera'], // 可以指定来源是相册还是相机，默认二者都有
        success: function (res) {
            uploadFile(res.tempFiles[0].path);
        }
    })
};

module.exports = uploadFile;