在android中的assets/raw文件夹中的TextView中显示pdf

Question

I have two activity,MainActivity.java and SampleActivity.java.I have stored a .pdf file in assets folder. I have a button in my first activity.When i click that button i want the pdf file to be displayed in the textview of SampleActivity.java. The second activity also will have a download button to download the pdf file.

I don't want to make use of webview or display using external program. I tried with .txt files and it worked correctly but same did'nt work with pdf file.

Is there any method to achieve this.

Thanks in advance.

Code that i used for .txt is

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_sample);

    txt=(TextView) findViewById(R.id.textView1);

    try
    {
        InputStream is=getAssets().open("hello.txt");
        int size=is.available();
        byte[] buffer=new byte[size];
        is.read(buffer);
        is.close();

        String text=new String(buffer);

        txt.setText(text);
    }
    catch(Exception e)
    {
        e.printStackTrace();
    }

Answer 1

When i click that button i want the pdf file to be displayed in the textview of SampleActivity.java.

That is not possible. TextView cannot render a PDF.

On Android 5.0+, there is some stuff in the printing framework to convert a PDF into images, with an eye towards print preview. You should be able to get that to work with an ImageView , though I have not played with it yet. Also, right now, Android 5.0+ represents ~10% of Android devices.

Or, you are welcome to find a PDF rendering library that you include in your app.

The second activity also will have a download button to download the pdf file.

That is not possible, insofar as you cannot replace a PDF file that is in assets/ . Assets are read-only at runtime. You are welcome to download a PDF file to someplace that is read/write, like internal storage. However, you still cannot display the PDF file in a TextView .

I tried with .txt files and it worked correctly but same did'nt work with pdf file.

In addition to all the problems mentioned above, PDF files are not text files. They are binary files. You cannot read a PDF into a String .

Answer 2

Below is code where you can show pdf (from Assets Folder) content in imageview in Android

private void openPDF() throws IOException {

    //open file in assets


    File fileCopy = new File(getCacheDir(), "source_of_information.pdf");

    InputStream input = getAssets().open("source_of_information.pdf");
    FileOutputStream output = new FileOutputStream(fileCopy);

    byte[] buffer = new byte[1024];
    int size;
    // Copy the entire contents of the file
    while ((size = input.read(buffer)) != -1) {
        output.write(buffer, 0, size);
    }
    //Close the buffer
    input.close();
    output.close();

    // We get a page from the PDF doc by calling 'open'
    ParcelFileDescriptor fileDescriptor =
            ParcelFileDescriptor.open(fileCopy,
                    ParcelFileDescriptor.MODE_READ_ONLY);
    PdfRenderer mPdfRenderer = new PdfRenderer(fileDescriptor);
    PdfRenderer.Page mPdfPage = mPdfRenderer.openPage(0);

    // Create a new bitmap and render the page contents into it
    Bitmap bitmap = Bitmap.createBitmap(mPdfPage.getWidth(),
            mPdfPage.getHeight(),
            Bitmap.Config.ARGB_8888);
    mPdfPage.render(bitmap, null, null, PdfRenderer.Page.RENDER_MODE_FOR_DISPLAY);

    // Set the bitmap in the ImageView
    imageView.setImageBitmap(bitmap);
}