Question

我使用以下代码从网站下载视频。下载功能正常，我的进度条有一个小问题。进度条保持不变，并且不会随着值的增加而更新。

@Override
protected Dialog onCreateDialog(int id) {
    switch (id) {
        case progress_bar_type: // we set this to 0
            pDialog = new ProgressDialog(this);
            pDialog.setMessage("Downloading file. Please wait...");
            pDialog.setIndeterminate(false);
            pDialog.setMax(100);
            pDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
            pDialog.setCancelable(true);
            pDialog.show();
            return pDialog;
        default:
            return null;
    }
}

class DownloadFile1 extends AsyncTask<String, Integer, String> {
    ProgressDialog bar;
    public String videoToDownload;
    public String fileName;

    /**
     * Before starting background thread
     * Show Progress Bar Dialog
     */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        showDialog(progress_bar_type);
    }

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

        try {
            mp4load(videoToDownload);
        } catch (Exception e) {
            // TODO: handle exception
        }

        return null;
    }

    public void mp4load(String urling) {
        try {
            System.out.println("Downloading");
            URL url = new URL(urling);
            HttpURLConnection con = (HttpURLConnection) url.openConnection();
            con.setRequestMethod("GET");
            //c.setDoOutput(true);
            con.connect();

            // String downloadsPath = Environment.getExternalStoragePublicDirectory();
            File SDCardRoot = Environment.getExternalStorageDirectory();

            File outputFile = new File(SDCardRoot, fileName);

            if (!outputFile.exists()) {
                outputFile.createNewFile();
            }

            FileOutputStream fos = new FileOutputStream(outputFile);

            int status = con.getResponseCode();

            InputStream is = con.getInputStream();

            byte[] buffer = new byte[1024];
            int len1 = 0;
            while ((len1 = is.read(buffer)) != -1) {
                fos.write(buffer, 0, len1);
            }
            fos.close();
            is.close();
            System.out.println("Downloaded");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

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

    /**
     * After completing background task
     * Dismiss the progress dialog
     **/
    @Override
    protected void onPostExecute(String file_url) {
        // dismiss the dialog after the file was downloaded
        dismissDialog(progress_bar_type);
    }
}

进度条完全保持0％的进度，并在下载完成后消失。 如何更改进度条的更新部分？

Answer 1

在doInBackground中调用public class MainController : Controller { public ILogger Logger { get; set; } public IIocResolver IocResolver { get; set; } // Add public ActionResult Index(string SessionID) { Logger.Info("MainController - inside Index"); using (var wrapper = IocResolver.ResolveAsDisposable<RecordManager>(new { sessionID = SessionID })) // Modify { var recordMgr = wrapper.Object; // Add recordMgr.PushRecords(); } } } public class RecordManager : ITransientDependency // Modify { public ILogger Logger { get; set; } private string _sessionID = string.Empty; public RecordManager(string sessionID, ILogger logger) // Modify { _sessionID = sessionID; Logger = logger; // Modify Logger.Info("RecordManager - inside constructor"); } public void PushRecords() { Logger.Info("RecordManager - PushRecords - start"); } }方法传递一个Integer，在进度条中设置。

publishProgress

您需要将方法mp4load的代码移动到doInBackground，以便像这样修改代码：

protected String doInBackground(String... params) {
    int count;

    try {
        mp4load(videoToDownload);
    } catch (Exception e) {
        // TODO: handle exception
    }

    return null;
}

这个想法很简单，您需要获取文件的大小，并在下载文件时慢慢更新进度条。

Answer 2

参考AsyncTask Docs，您的进度类型参数必须是整数，因为您的AsyncTask类声明如下。

class DownloadFile1 extends AsyncTask<String, Integer, String> {

因此，请更改

public void onProgressUpdate(String..Progress)

到public void onProgressUpdate(Integer..Progress)

然后使用覆盖注释

显示进度条直到下载完成 - Android

2 个答案: