2

在开发允许用户检查新应用程序更新的功能时，我被困了好几天（我使用本地服务器作为我的分发点）。问题是下载进度似乎运行良好，但我在手机的任何地方都找不到下载的文件（我没有 sd 卡/外部存储器）。以下是我到目前为止所做的。

 class DownloadFileFromURL extends AsyncTask<String, String, String> {
    ProgressDialog pd;
    String path = getFilesDir() + "/myapp.apk";
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pd = new ProgressDialog(DashboardActivity.this);
        pd.setTitle("Processing...");
        pd.setMessage("Please wait.");
        pd.setMax(100);
        pd.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
        pd.setCancelable(true);
        //pd.setIndeterminate(true);
        pd.show();

    }

    /**
     * Downloading file in background thread
     * */
    @Override
    protected String doInBackground(String... f_url) {
        int count;

        try {

            URL url = new URL(f_url[0]);
            URLConnection conection = url.openConnection();
            conection.connect();

            // download the file
            InputStream input = new BufferedInputStream(url.openStream());
            OutputStream output = new FileOutputStream(path);

            byte data[] = new byte[1024];

            long total = 0;

            while ((count = input.read(data)) != -1) {
                total += count;
                publishProgress("" + (int) ((total * 100) / lenghtOfFile));

                // writing data to file
                output.write(data, 0, count);
            }

            // flushing output
            output.flush();
            // closing streams
            output.close();
            input.close();

        } catch (Exception e) {
            Log.e("Error: ", e.getMessage());
        }
        return path;
    }

    protected void onProgressUpdate(String... progress) {
        pd.setProgress(Integer.parseInt(progress[0]));
    }

    @Override
    protected void onPostExecute(String file_url) {
        // dismiss the dialog after the file was downloaded
        if (pd!=null) {
            pd.dismiss();
        }
    // i am going to run the file after download finished
        StrictMode.VmPolicy.Builder builder = new StrictMode.VmPolicy.Builder();
        StrictMode.setVmPolicy(builder.build());

        Intent i = new Intent(Intent.ACTION_VIEW);

        i.setDataAndType(Uri.fromFile(new File(file_url)), "application/vnd.android.package-archive" );
        i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        Log.d("Lofting", "About to install new .apk");

        getApplicationContext().startActivity(i);
    }

}

进度对话框达到 100% 并关闭后，我找不到该文件。我认为这就是应用程序无法继续安装下载的 apk 的原因。

我错过了一些代码吗？

4

2 回答 2

6

我不敢相信我解决了这个问题。我所做的是替换：

getFilesDir()

到

Environment.getExternalStorageDirectory()

下面我发布我的最终代码

    class DownloadFileFromURL extends AsyncTask<String, String, String> {
    ProgressDialog pd;
    String pathFolder = "";
    String pathFile = "";

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pd = new ProgressDialog(DashboardActivity.this);
        pd.setTitle("Processing...");
        pd.setMessage("Please wait.");
        pd.setMax(100);
        pd.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
        pd.setCancelable(true);
        pd.show();
    }

    @Override
    protected String doInBackground(String... f_url) {
        int count;

        try {
            pathFolder = Environment.getExternalStorageDirectory() + "/YourAppDataFolder";
            pathFile = pathFolder + "/yourappname.apk";
            File futureStudioIconFile = new File(pathFolder);
            if(!futureStudioIconFile.exists()){
                futureStudioIconFile.mkdirs();
            }

            URL url = new URL(f_url[0]);
            URLConnection connection = url.openConnection();
            connection.connect();

            // this will be useful so that you can show a tipical 0-100%
            // progress bar
            int lengthOfFile = connection.getContentLength();

            // download the file
            InputStream input = new BufferedInputStream(url.openStream());
            FileOutputStream output = new FileOutputStream(pathFile);

            byte data[] = new byte[1024]; //anybody know what 1024 means ?
            long total = 0;
            while ((count = input.read(data)) != -1) {
                total += count;
                // publishing the progress....
                // After this onProgressUpdate will be called
                publishProgress("" + (int) ((total * 100) / lengthOfFile));

                // writing data to file
                output.write(data, 0, count);
            }

            // flushing output
            output.flush();

            // closing streams
            output.close();
            input.close();


        } catch (Exception e) {
            Log.e("Error: ", e.getMessage());
        }

        return pathFile;
    }

    protected void onProgressUpdate(String... progress) {
        // setting progress percentage
        pd.setProgress(Integer.parseInt(progress[0]));
    }

    @Override
    protected void onPostExecute(String file_url) {
        if (pd!=null) {
            pd.dismiss();
        }
        StrictMode.VmPolicy.Builder builder = new StrictMode.VmPolicy.Builder();
        StrictMode.setVmPolicy(builder.build());
        Intent i = new Intent(Intent.ACTION_VIEW);

        i.setDataAndType(Uri.fromFile(new File(file_url)), "application/vnd.android.package-archive" );
        i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

        getApplicationContext().startActivity(i);
    }

}

简单地把这段代码使用这个类

new DownloadFileFromURL().execute("http://www.yourwebsite.com/download/yourfile.apk");

此代码可以使用进度条将文件下载到您的内部手机存储，并继续询问您的应用程序安装权限。

好好享受。

于 2018-11-22T07:30:41.007 回答
0

正如我们所知getFilesDir()，返回文件系统上创建文件的目录的绝对路径，这将为您提供路径/data/data/your package/files

所以你可以在那里找到文件（如果完全下载）

我建议你阅读这篇文章：

如何获取每个目录路径

于 2018-11-19T08:19:47.380 回答