加载pdf文件时显示进度条

Question

我对android开发相当陌生，所以我试图制作的是可以从url显示pdf的应用程序，

我想在从网络加载 pdf 文件时显示进度条（某些 pdf 文件超过 15mb）我该怎么做？

我正在使用com.github.barteksc.pdfviewer.PDFView从网络显示pdf

这是我的 pdf 展示活动

private PDFView mPDFview;

private String mStoreId;

private FirebaseDatabase mFirebaseDatabase;
private DatabaseReference mReference;



@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_flyer);


    mFirebaseDatabase = FirebaseDatabase.getInstance();
    mReference = mFirebaseDatabase.getReference("Store");

    if (getIntent()!=null)
    {
        mStoreId = getIntent().getStringExtra("StoreId");
    }

    if (!mStoreId.isEmpty())
    {
        getUrlStoreFlyer(mStoreId);
    }

}

private void getUrlStoreFlyer(String storeId) {
    mReference.child(storeId).addValueEventListener(new ValueEventListener() 
{
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            Store storeChain = dataSnapshot.getValue(Store.class);
            String pdfUrl = storeChain.getFlyerPDF().toString();
            mPDFview = findViewById(R.id.flyer_pdfView);
            new RetrievePDFStream().execute(pdfUrl);
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {
        }
    });
}

class RetrievePDFStream extends AsyncTask<String, Void, InputStream>
{
    @Override
    protected InputStream doInBackground(String... strings)
    {
        InputStream inputStream = null;
        try{
            URL url = new URL(strings[0]);
            HttpURLConnection urlConnection = (HttpURLConnection)url.openConnection();

            if (urlConnection.getResponseCode()==200)
            {
                inputStream = new BufferedInputStream(urlConnection.getInputStream());
            }
        }
        catch (IOException e)
        {
            return null;
        }

        return inputStream;
    }

    @Override
    protected void onPostExecute(InputStream inputStream) {
        mPDFview.fromStream(inputStream).load();
    }
}

@Override
public void onBackPressed() {
    finish();
    overridePendingTransition(0, 0);
}
}

这是我的 xml

    <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.test.FlyerActivity">


    <ProgressBar

        android:layout_width="50dp"
        android:layout_height="50dp"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="150dp"
        android:id="@+id/progressBar2" />



    <com.github.barteksc.pdfviewer.PDFView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/flyer_pdfView"/>
    enter code here

</RelativeLayout>

Answer 1

这是我使用过并且效果完美的：

   @Override
    protected void onPostExecute(InputStream inputStream) {

        mPDFview.fromStream(inputStream).onLoad(new OnLoadCompleteListener() {
            @Override
            public void loadComplete(int nbPages) {
                ProgressBar progressBar = (ProgressBar) findViewById(R.id.progressBar2);
                progressBar.setVisibility(View.GONE);
            }
        }).load();

    }