private void startDownload(UpdateAppBean updateApp, final DownloadCallback callback) {

        mDismissNotificationProgress = updateApp.isDismissNotificationProgress();

        String apkUrl = updateApp.getApkFileUrl();
        if (TextUtils.isEmpty(apkUrl)) {
            String contentText = "新版本下载路径错误";
            stop(contentText);
            return;
        }
        String appName = AppUpdateUtils.getApkName(updateApp);

        File appDir = new File(updateApp.getTargetPath());
        if (!appDir.exists()) {
            appDir.mkdirs();
        }

        String target = appDir + File.separator + updateApp.getNewVersion();

        updateApp.getHttpManager().download(apkUrl, target, appName, new FileDownloadCallBack(callback));
    }

    private void stop(String contentText) {
        if (mBuilder != null) {
            mBuilder.setContentTitle(AppUpdateUtils.getAppName(DownloadService.this)).setContentText(contentText);
            Notification notification = mBuilder.build();
            notification.flags = Notification.FLAG_AUTO_CANCEL;
            mNotificationManager.notify(NOTIFY_ID, notification);
        }
        close();
    }

    private void close() {
        stopSelf();
        isRunning = false;
    }

    /**
     * 进度条回调接口
     */
    public interface DownloadCallback {
       // 新增下面的回调口子
        /**
         * 当应用处于前台，准备执行安装程序时候的回调，
         *
         * @param file
         * @return
         */
        boolean onInstallAppAndAppOnForeground(File file);
    }

 @Override
        public void onResponse(File file) {
            if (mCallBack != null) {
                if (!mCallBack.onFinish(file)) {
                    close();
                    return;
                }
            }

            try {

                if (AppUpdateUtils.isAppOnForeground(DownloadService.this) || mBuilder == null) {
                    //App前台运行
                    mNotificationManager.cancel(NOTIFY_ID);
                    **// 给应用开发者相应的权限去控制，是否自己处理**
                    boolean temp = mCallBack.onInstallAppAndAppOnForeground(file);
                    if (!temp) {
                        AppUpdateUtils.installApp(DownloadService.this, file);
                    }

 /**
     * 回调监听下载
     */
    private void startDownloadApp(DownloadService.DownloadBinder binder) {
        // 开始下载，监听下载进度，可以用对话框显示
        if (mUpdateApp != null) {

            binder.start(mUpdateApp, new DownloadService.DownloadCallback() {
               //....

                **@Override
                public boolean onInstallAppAndAppOnForeground(File file) {
                    // 如果应用处于前台，那么就自行处理应用安装
                    AppUpdateUtils.installApp(UpdateDialogFragment.this.getActivity(), file);
                    dismiss();
                    return true;
                }**
            });
        }
    }

@Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        switch (resultCode) {
            case Activity.RESULT_OK:
                break;
            **case Activity.DEFAULT_KEYS_DIALER:
                switch (requestCode){
                    // 得到通过UpdateDialogFragment默认dialog方式安装，用户取消安装的回调通知，以便用户自己去判断，比如这个更新如果是强制的，但是用户下载之后取消了，在这里发起相应的操作
                    case AppUpdateUtils.REQ_CODE_INSTALL_APP:
                        Toast.makeText(this,"用户取消了安装包的更新", Toast.LENGTH_LONG).show();
                        break;
                }
                break;**
            case Activity.RESULT_CANCELED:
                break;
            default:
        }
    }