需要帮助PDF页面转换成位图在Android中Java的 [英] Need help to convert a Pdf page into Bitmap in Android Java
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问题描述
我需要转换PDFfile（PDF页）成位图（或图像文件）在Android中。我已经通过很多论坛了。但没有解决我的问题。
I need to convert PDFfile(PDF page) into a Bitmap(or Image file) in Android.. I have gone through many forums.. But nothing resolves my issue..
从Apache.But 1.适用PDFBOX罐子它使用的是不支持Android的一些Java类。 2.尝试iText的罐子它转换图像为PDF（我需要它的反向操作） 就像我已经尝试过很多罐子。但是，没有阳性结果。
1.Used Pdfbox jar from Apache.But it uses some java classes that is not supported in android. 2. Tried Itext jar which converts image to pdf(I need its reverse operation) Like that I have tried many jars. But no positive result.
请帮我在这。
byte[] bytes;
try {
File file = new File(this.getFilesDir().getAbsolutePath()+"/2010Q2_SDK_Overview.pdf");
FileInputStream is = new FileInputStream(file);
// Get the size of the file
long length = file.length();
bytes = new byte[(int) length];
int offset = 0;
int numRead = 0;
while (offset < bytes.length && (numRead=is.read(bytes, offset, bytes.length-offset)) >= 0) {
offset += numRead;
}
ByteBuffer buffer = ByteBuffer.NEW(bytes);
String data = Base64.encodeToString(bytes, Base64.DEFAULT);
PDFFile pdf_file = new PDFFile(buffer);
PDFPage page = pdf_file.getPage(2);
RectF rect = new RectF(0, 0, (int) page.getBBox().width(),
(int) page.getBBox().height());
// Bitmap bufferedImage = Bitmap.createBitmap((int)rect.width(), (int)rect.height(),
// Bitmap.Config.ARGB_8888);
Bitmap image = page.getImage((int)rect.width(), (int)rect.height(), rect);
FileOutputStream os = new FileOutputStream(this.getFilesDir().getAbsolutePath()+"/pdf.jpg");
image.compress(Bitmap.CompressFormat.JPEG, 80, os);
// ((ImageView) findViewById(R.id.testView)).setImageBitmap(image);
我收到的图像文件，
I am getting the Image File,
相反的，
Instead of,
package com.test123;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import com.sun.pdfview.PDFFile;
import com.sun.pdfview.PDFPage;
import net.sf.andpdf.nio.ByteBuffer;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.RectF;
import android.os.Bundle;
import android.util.Base64;
public class Test123Activity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
byte[] bytes;
try {
File file = new File(this.getFilesDir().getAbsolutePath()+"/2010Q2_SDK_Overview.pdf");
FileInputStream is = new FileInputStream(file);
// Get the size of the file
long length = file.length();
bytes = new byte[(int) length];
int offset = 0;
int numRead = 0;
while (offset < bytes.length && (numRead=is.read(bytes, offset, bytes.length-offset)) >= 0) {
offset += numRead;
}
ByteBuffer buffer = ByteBuffer.NEW(bytes);
String data = Base64.encodeToString(bytes, Base64.DEFAULT);
PDFFile pdf_file = new PDFFile(buffer);
PDFPage page = pdf_file.getPage(2);
RectF rect = new RectF(0, 0, (int) page.getBBox().width(),
(int) page.getBBox().height());
// Bitmap bufferedImage = Bitmap.createBitmap((int)rect.width(), (int)rect.height(),
// Bitmap.Config.ARGB_8888);
Bitmap image = page.getImage((int)rect.width(), (int)rect.height(), rect);
FileOutputStream os = new FileOutputStream(this.getFilesDir().getAbsolutePath()+"/pdf.jpg");
image.compress(Bitmap.CompressFormat.JPEG, 80, os);
//((ImageView) findViewById(R.id.testView)).setImageBitmap(image);
} catch (Exception e) {
e.printStackTrace();
}
}
}
有人请帮我解决这个问题。否则告诉我，使用中的应用程序功能，内置的显示在android的PDF文件中的任何其他方式。
Anybody please help me to resolve this. Else tell me any other way to display pdf file in android using function inbuilt within application.
推荐答案
我解决了这个问题。它的简单，只要让该设备有时间来呈现每个页面。
I solved this issue. its as simple as letting the device have time to render each page.
要解决这个问题你需要做的是改变
To fix this all you have to do is change
PDFPage page = pdf_file.getPage(2);
到
PDFPage page = pdf_file.getPage(2, true);
首先，查看Android的PDF文档，你必须将PDF转换成图像，然后将它们显示给用户。 （我要使用的WebView）
Firstly to view a PDF in Android you have to convert the PDF into images then display them to the user. (I am going to use a webview)
因此，要做到这一点，我们需要这个库。正是这种
So to do this we need this library. It is my edited version of this git.
在导入库到你的项目，你需要创建活动。
After you have imported the library into your project you need to create your activity.
中的XML：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<WebView
android:id="@+id/webView1"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
Java的：
The java:
//Imports:
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.util.Base64;
import android.util.Log;
import android.view.View;
import android.view.ViewTreeObserver;
import android.webkit.WebView;
import com.sun.pdfview.PDFFile;
import com.sun.pdfview.PDFImage;
import com.sun.pdfview.PDFPage;
import com.sun.pdfview.PDFPaint;
import net.sf.andpdf.nio.ByteBuffer;
import net.sf.andpdf.refs.HardReference;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.RandomAccessFile;
import java.nio.channels.FileChannel;
//Globals:
private WebView wv;
private int ViewSize = 0;
//OnCreate Method:
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//Settings
PDFImage.sShowImages = true; // show images
PDFPaint.s_doAntiAlias = true; // make text smooth
HardReference.sKeepCaches = true; // save images in cache
//Setup webview
wv = (WebView)findViewById(R.id.webView1);
wv.getSettings().setBuiltInZoomControls(true);//show zoom buttons
wv.getSettings().setSupportZoom(true);//allow zoom
//get the width of the webview
wv.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener()
{
@Override
public void onGlobalLayout()
{
ViewSize = wv.getWidth();
wv.getViewTreeObserver().removeGlobalOnLayoutListener(this);
}
});
try
{
File file = new File(Environment.getExternalStorageDirectory().getPath() + "/randompdf.pdf");
RandomAccessFile f = new RandomAccessFile(file, "r");
byte[] data = new byte[(int)f.length()];
f.readFully(data);
pdfLoadImages(data);
}
catch(Exception ignored)
{
}
}
//Load Images:
private void pdfLoadImages(final byte[] data)
{
try
{
// run async
new AsyncTask<Void, Void, String>()
{
// create and show a progress dialog
ProgressDialog progressDialog = ProgressDialog.show(MainActivity.this, "", "Opening...");
@Override
protected void onPostExecute(String html)
{
//after async close progress dialog
progressDialog.dismiss();
//load the html in the webview
wv.loadDataWithBaseURL("", html, "text/html","UTF-8", "");
}
@Override
protected String doInBackground(Void... params)
{
try
{
//create pdf document object from bytes
ByteBuffer bb = ByteBuffer.NEW(data);
PDFFile pdf = new PDFFile(bb);
//Get the first page from the pdf doc
PDFPage PDFpage = pdf.getPage(1, true);
//create a scaling value according to the WebView Width
final float scale = ViewSize / PDFpage.getWidth() * 0.95f;
//convert the page into a bitmap with a scaling value
Bitmap page = PDFpage.getImage((int)(PDFpage.getWidth() * scale), (int)(PDFpage.getHeight() * scale), null, true, true);
//save the bitmap to a byte array
ByteArrayOutputStream stream = new ByteArrayOutputStream();
page.compress(Bitmap.CompressFormat.PNG, 100, stream);
byte[] byteArray = stream.toByteArray();
stream.reset();
//convert the byte array to a base64 string
String base64 = Base64.encodeToString(byteArray, Base64.NO_WRAP);
//create the html + add the first image to the html
String html = "<!DOCTYPE html><html><body bgcolor=\"#b4b4b4\"><img src=\"data:image/png;base64,"+base64+"\" hspace=10 vspace=10><br>";
//loop though the rest of the pages and repeat the above
for(int i = 2; i <= pdf.getNumPages(); i++)
{
PDFpage = pdf.getPage(i, true);
page = PDFpage.getImage((int)(PDFpage.getWidth() * scale), (int)(PDFpage.getHeight() * scale), null, true, true);
page.compress(Bitmap.CompressFormat.PNG, 100, stream);
byteArray = stream.toByteArray();
stream.reset();
base64 = Base64.encodeToString(byteArray, Base64.NO_WRAP);
html += "<img src=\"data:image/png;base64,"+base64+"\" hspace=10 vspace=10><br>";
}
stream.close();
html += "</body></html>";
return html;
}
catch (Exception e)
{
Log.d("error", e.toString());
}
return null;
}
}.execute();
System.gc();// run GC
}
catch (Exception e)
{
Log.d("error", e.toString());
}
}
这篇关于需要帮助PDF页面转换成位图在Android中Java的的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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