渲染2 + pdf文件

Question

我最近学会了如何将pdf文件呈现到应用程序中。当我尝试使用一个pdf时它工作得很好，但现在当我尝试2时，它会自动选择我制作的最后一个资产（pdf）。

mainActivity中的代码：

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.view.View;
import android.widget.LinearLayout;

public class MainActivity extends AppCompatActivity {

    private View btnRender;
    private LinearLayout container;
    private View btnRendered;


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

        btnRender = (View)findViewById(R.id.btn_render);
        container = (LinearLayout)findViewById(R.id.fragment_layout);
        btnRendered = (View) findViewById(R.id.btn_rendered);

        //set event handling for button
        btnRender.setOnClickListener(onClickListener());
    }

    private View.OnClickListener onClickListener() {


        return new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                switch(v.getId()){
                    case R.id.btn_render:

                     //replace fragment when clicked
                FragmentManager fm = getSupportFragmentManager();
                FragmentTransaction ft = fm.beginTransaction();
                ft.replace(R.id.fragment_layout, new PDFRenderFragment());
                ft.commit();

                //gone button after all
                btnRender.setVisibility(View.GONE);
                container.setVisibility(View.VISIBLE);
                        break;
                    case R.id.btn_rendered:
                        FragmentManager fz = getSupportFragmentManager();
                        FragmentTransaction fy = fz.beginTransaction();
                        fy.replace(R.id.fragment_layout, new PDFRenderAgment());
                        fy.commit();

                        //gone button after all
                        btnRender.setVisibility(View.GONE);
                        container.setVisibility(View.VISIBLE);

                        break;
            }
        };
    };



}}

首先是pdf：

import android.app.Fragment;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.pdf.PdfRenderer;
import android.os.Bundle;
import android.os.ParcelFileDescriptor;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ImageView;

import java.io.IOException;



public class PDFRenderFragment extends android.support.v4.app.Fragment {

    private ParcelFileDescriptor fileDescriptor;
    private PdfRenderer pdfRenderer;
    private PdfRenderer.Page currentPage;
    private ImageView image;
    private Button btnPrevious;
    private Button btnNext;

    public PDFRenderFragment() {

    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_pdfrender, container, false);
    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        // Retain view references.
        image = (ImageView) view.findViewById(R.id.image);
        btnPrevious = (Button) view.findViewById(R.id.btn_previous);
        btnNext = (Button) view.findViewById(R.id.btn_next);

        //set buttons event
        btnPrevious.setOnClickListener(onActionListener(-1)); //previous button clicked
        btnNext.setOnClickListener(onActionListener(1)); //next button clicked

        int index = 0;
        // If there is a savedInstanceState (screen orientations, etc.), we restore the page index.
        if (null != savedInstanceState) {
            index = savedInstanceState.getInt("current_page", 0);
        }
        showPage(index);
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        try {
            openRenderer(activity);
        } catch (IOException e) {
            e.printStackTrace();
            Log.i("Fragment", "Error occurred!");
            Log.e("Fragment", e.getMessage());
            activity.finish();
        }
    }

    @Override
    public void onDestroy() {
        try {
            closeRenderer();
        } catch (IOException e) {
            e.printStackTrace();
        }
        super.onDestroy();
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        if (null != currentPage) {
            outState.putInt("current_page", currentPage.getIndex());
        }
    }

    /**
     * Create a PDF renderer
     * @param activity
     * @throws IOException
     */
    private void openRenderer(Activity activity) throws IOException {
        // Reading a PDF file from the assets directory.
        fileDescriptor = activity.getAssets().openFd("biology_in_c.pdf").getParcelFileDescriptor();

        // This is the PdfRenderer we use to render the PDF.
        pdfRenderer = new PdfRenderer(fileDescriptor);
    }

    /**
     * Closes PdfRenderer and related resources.
     */
    private void closeRenderer() throws IOException {
        if (null != currentPage) {
            currentPage.close();
        }
        pdfRenderer.close();
        fileDescriptor.close();
    }

    /**
     * Shows the specified page of PDF file to screen
     * @param index The page index.
     */
    private void showPage(int index) {
        if (pdfRenderer.getPageCount() <= index) {
            return;
        }
        // Make sure to close the current page before opening another one.
        if (null != currentPage) {
            currentPage.close();
        }
        //open a specific page in PDF file
        currentPage = pdfRenderer.openPage(index);
        // Important: the destination bitmap must be ARGB (not RGB).
        Bitmap bitmap = Bitmap.createBitmap(currentPage.getWidth(), currentPage.getHeight(),
                Bitmap.Config.ARGB_8888);
        // Here, we render the page onto the Bitmap.
        currentPage.render(bitmap, null, null, PdfRenderer.Page.RENDER_MODE_FOR_DISPLAY);
        // showing bitmap to an imageview
        image.setImageBitmap(bitmap);
        updateUIData();
    }

    /**
     * Updates the state of 2 control buttons in response to the current page index.
     */
    private void updateUIData() {
        int index = currentPage.getIndex();
        int pageCount = pdfRenderer.getPageCount();
        btnPrevious.setEnabled(0 != index);
        btnNext.setEnabled(index + 1 < pageCount);
        getActivity().setTitle(getString(R.string.app_name , index + 1, pageCount));
    }

    private View.OnClickListener onActionListener(final int i) {
        return new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                if (i < 0) {//go to previous page
                    showPage(currentPage.getIndex() - 1);
                } else {
                    showPage(currentPage.getIndex() + 1);
                }
            }
        };
    }
}

第二个pdf：

import android.app.Fragment;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.pdf.PdfRenderer;
import android.os.Bundle;
import android.os.ParcelFileDescriptor;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ImageView;

import java.io.IOException;


public class PDFRenderAgment extends android.support.v4.app.Fragment {

    private ParcelFileDescriptor fileDescriptor;
    private PdfRenderer pdfRenderer;
    private PdfRenderer.Page currentPage;
    private ImageView image;
    private Button btnPrevious;
    private Button btnNext;

    public PDFRenderAgment() {

    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_pdfrender, container, false);
    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        // Retain view references.
        image = (ImageView) view.findViewById(R.id.image);
        btnPrevious = (Button) view.findViewById(R.id.btn_previous);
        btnNext = (Button) view.findViewById(R.id.btn_next);

        //set buttons event
        btnPrevious.setOnClickListener(onActionListener(-1)); //previous button clicked
        btnNext.setOnClickListener(onActionListener(1)); //next button clicked

        int index = 0;
        // If there is a savedInstanceState (screen orientations, etc.), we restore the page index.
        if (null != savedInstanceState) {
            index = savedInstanceState.getInt("current_page", 0);
        }
        showPage(index);
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        try {
            openRenderer(activity);
        } catch (IOException e) {
            e.printStackTrace();
            Log.i("Fragment", "Error occurred!");
            Log.e("Fragment", e.getMessage());
            activity.finish();
        }
    }

    @Override
    public void onDestroy() {
        try {
            closeRenderer();
        } catch (IOException e) {
            e.printStackTrace();
        }
        super.onDestroy();
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        if (null != currentPage) {
            outState.putInt("current_page", currentPage.getIndex());
        }
    }

    /**
     * Create a PDF renderer
     * @param activity
     * @throws IOException
     */
    private void openRenderer(Activity activity) throws IOException {
        // Reading a PDF file from the assets directory.
        fileDescriptor = activity.getAssets().openFd("biology_in_f.pdf").getParcelFileDescriptor();

        // This is the PdfRenderer we use to render the PDF.
        pdfRenderer = new PdfRenderer(fileDescriptor);
    }

    /**
     * Closes PdfRenderer and related resources.
     */
    private void closeRenderer() throws IOException {
        if (null != currentPage) {
            currentPage.close();
        }
        pdfRenderer.close();
        fileDescriptor.close();
    }

    /**
     * Shows the specified page of PDF file to screen
     * @param index The page index.
     */
    private void showPage(int index) {
        if (pdfRenderer.getPageCount() <= index) {
            return;
        }
        // Make sure to close the current page before opening another one.
        if (null != currentPage) {
            currentPage.close();
        }
        //open a specific page in PDF file
        currentPage = pdfRenderer.openPage(index);
        // Important: the destination bitmap must be ARGB (not RGB).
        Bitmap bitmap = Bitmap.createBitmap(currentPage.getWidth(), currentPage.getHeight(),
                Bitmap.Config.ARGB_8888);
        // Here, we render the page onto the Bitmap.
        currentPage.render(bitmap, null, null, PdfRenderer.Page.RENDER_MODE_FOR_DISPLAY);
        // showing bitmap to an imageview
        image.setImageBitmap(bitmap);
        updateUIData();
    }

    /**
     * Updates the state of 2 control buttons in response to the current page index.
     */
    private void updateUIData() {
        int index = currentPage.getIndex();
        int pageCount = pdfRenderer.getPageCount();
        btnPrevious.setEnabled(0 != index);
        btnNext.setEnabled(index + 1 < pageCount);
        getActivity().setTitle(getString(R.string.app_name , index + 1, pageCount));
    }

    private View.OnClickListener onActionListener(final int i) {
        return new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                if (i < 0) {//go to previous page
                    showPage(currentPage.getIndex() - 1);
                } else {
                    showPage(currentPage.getIndex() + 1);
                }
            }
        };
    }
}

没有语法错误，这让我相信“逻辑”中存在一些错误。编码。如果有人能回答这个问题，我将不胜感激！