运行代码时显示进度对话框的问题

Question

我试图在执行长时间运行的代码时显示一个带有百分比的进度对话框，我为此使用了 AsyncTask 但它不起作用，功能如下：我获取所有画廊图像的数组路径，然后我处理这些图像并提取每个图像的描述符向量并将其转换为 JSON 字符串，然后将这些字符串存储到 sqlite，但是我的代码需要很多时间（几分钟），所以我需要的是显示一个进度对话框，其中百分比为了知道任务的开始和结束，这个任务我需要在按下按钮时启动它。以下是我的代码：

public void FillDataBase(){

    ArrayList<String> paths = getFilePaths();
    for (int i = 0; i < paths.size(); i++) {

        Mat mat = new Mat();

        BitmapFactory.Options bmOptions1 = new BitmapFactory.Options();
        //bmOptions1.inSampleSize=4;
        Bitmap bitmap0 = BitmapFactory.decodeFile(paths.get(i).toString(), bmOptions1);

        Bitmap bitmap = getRotated(bitmap0, paths.get(i).toString());

        //Utils.bitmapToMat(bitmap, mat);

        Mat matRGB = new Mat();
        Utils.bitmapToMat(bitmap, matRGB);
        Imgproc.cvtColor(matRGB, mat, Imgproc.COLOR_RGB2GRAY);

        org.opencv.core.Size s2 = new Size(3, 3);
        Imgproc.GaussianBlur(mat, mat, s2, 2);


        FeatureDetector detector2 = FeatureDetector.create(FeatureDetector.ORB);
        MatOfKeyPoint keypoints2 = new MatOfKeyPoint();
        detector2.detect(mat, keypoints2);


        DescriptorExtractor extractor2 = DescriptorExtractor.create(DescriptorExtractor.ORB);
        Mat descriptors2 = new Mat();
        extractor2.compute(mat, keypoints2, descriptors2);


        // String matimage = matToJson(mat);
        String matkeys= keypointsToJson(keypoints2);
        String desc = matToJson(descriptors2);

        mat m = new mat(desc, matkeys);
        DataBaseHandler db = new DataBaseHandler(getApplicationContext());
        db.addmat(m);

    }

Asynctask 代码（我在线程的 public void 运行中调用 FillDatabase()）：

private class ProgressTask extends AsyncTask<Void,Void,Void>{
    private int progressStatus=0;
    private Handler handler = new Handler();

    // Initialize a new instance of progress dialog
    private ProgressDialog pd = new ProgressDialog(RGBtoGrey.this);

    @Override
    protected void onPreExecute(){
        super.onPreExecute();
        pd.setIndeterminate(false);

        // Set progress style horizontal
        pd.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);

        // Set the progress dialog background color
        pd.getWindow().setBackgroundDrawable(new ColorDrawable(Color.YELLOW));

        // Make the progress dialog cancellable
        pd.setCancelable(true);
        // Set the maximum value of progress
        pd.setMax(100);
        // Finally, show the progress dialog
        pd.show();
    }

    @Override
    protected Void doInBackground(Void...args){
        // Set the progress status zero on each button click
        progressStatus = 0;

        // Start the lengthy operation in a background thread
        new Thread(new Runnable() {
            @Override
            public void run() {

                FillDataBase();

                while(progressStatus < 100){

                    // Update the progress status
                    progressStatus +=1;

                    // Try to sleep the thread for 20 milliseconds

                        try{
                            Thread.sleep(20);

                        }catch(InterruptedException e){
                            e.printStackTrace();
                        }


                    // Update the progress bar
                    handler.post(new Runnable() {
                        @Override
                        public void run() {
                            // Update the progress status
                            pd.setProgress(progressStatus);
                            // If task execution completed
                            if(progressStatus == 100){
                                // Dismiss/hide the progress dialog
                                pd.dismiss();
                            }
                        }
                    });
                }
            }
        }).start(); // Start the operation

        return null;
    }

    protected void onPostExecute(){
        // do something after async task completed.
    }

最后我这样调用 Asynctask：

testButton0.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

        new ProgressTask().execute();

                }

    });

Answer 1

你可以这样做：

private static class InsertAllPersonsToFirebaseTask extends AsyncTask<Void, Float, Void> {

    private List<Person> personList;
    private ElasticDownloadView mElasticDownloadView;
    private DatabaseReference mDatabase, pushedKey;
    private Person person;

    public InsertAllPersonsToFirebaseTask(List<Person> personList, ElasticDownloadView mElasticDownloadView) {
        this.personList = personList;
        this.mElasticDownloadView = mElasticDownloadView;

    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();

        if (mElasticDownloadView != null) {
            this.mElasticDownloadView.setVisibility(View.VISIBLE);
            this.mElasticDownloadView.startIntro();
        }
    }

    @Override
    protected Void doInBackground(Void... voids) {
        mDatabase = FirebaseDatabase.getInstance().getReference();

        for (int i = 0; i < personList.size(); i++){
            pushedKey = mDatabase.child("Persons").push();
            person = new Person();
            person.setPersonId(System.currentTimeMillis());
            person.setName(personList.get(i).getName());

            pushedKey.setValue(person);

            //This line is for update the onProgressUpdate() method
            publishProgress(((i+1)/(float)personList.size()* 100));

            if (isCancelled()){
                break;
            }
        }

        return null;
    }

    @Override
    protected void onProgressUpdate(Float... progress) {

        if (mElasticDownloadView != null){
            mElasticDownloadView.setProgress(progress[0]);
        }

    }

    @Override
    protected void onPostExecute(Void aVoid) {
        super.onPostExecute(aVoid);

        if (mElasticDownloadView != null){
            mElasticDownloadView.setVisibility(View.GONE);
        }
    }
}

您可以使用任何类型的进度条。我用过 ElasticDownloadview 进度条。

然后：

testButton0.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

         new InsertAllPersonsToFirebaseTask(personArrayList,mElasticDownloadView).execute();

                 }

    });