Android的库中不支持PDF。有没有办法在Android应用程序中呈现PDF文件?
当前回答
您可以通过导入使用一个简单的方法
implementation 'com.github.barteksc:android-pdf-viewer:2.8.2'
XML代码为
<com.github.barteksc.pdfviewer.PDFView
android:id="@+id/pdfv"
android:layout_width="match_parent"
android:layout_height="match_parent">
</com.github.barteksc.pdfviewer.PDFView>
只需声明并添加一个文件到资产文件夹并分配名称
PDFView pdfView=findViewById(R.id.pdfv);
pdfView.fromAsset("agl.pdf").load();
其他回答
您可以通过导入使用一个简单的方法
implementation 'com.github.barteksc:android-pdf-viewer:2.8.2'
XML代码为
<com.github.barteksc.pdfviewer.PDFView
android:id="@+id/pdfv"
android:layout_width="match_parent"
android:layout_height="match_parent">
</com.github.barteksc.pdfviewer.PDFView>
只需声明并添加一个文件到资产文件夹并分配名称
PDFView pdfView=findViewById(R.id.pdfv);
pdfView.fromAsset("agl.pdf").load();
为了给这一点增加一点光明,我将不得不使用Mozilla的pdf.js解决方案。下面是一个已经编写好的实现的链接:https://bitbucket.org/butelo/pdfviewer/。
以下是我在Android Activity中添加的编辑:
private String getInternalPDFURL(String interalPDFName){
return "file:///android_asset/pdfviewer/index.html?pdf=" + interalPDFName + ".pdf";
}
以下是我在pdffile.js中所做的编辑:
var url = '../' + getPDFURL();
function getPDFURL(){
var query = window.location.search.substring(1);
var vars = query.split("=");
var pdfPage = vars[1];
return pdfPage;
}
我从这篇文章和其他类似文章的一些答案中得出了一个混合的方法:
此解决方案检查PDF阅读器应用程序是否已安装,并执行以下操作: —如果设备上安装了PDF阅读器,请将PDF文件下载到设备上,并打开PDF阅读器应用 —如果没有安装阅读器,请询问用户是否希望通过谷歌Drive在线查看PDF文件
注意!这个解决方案使用了在API9 (Android 2.3或Gingerbread)中引入的Android DownloadManager类。这意味着它不能在Android 2.2或更早的版本上运行。
我在这里写了一篇关于它的博客文章,但为了完整性,我在下面提供了完整的代码:
public class PDFTools {
private static final String GOOGLE_DRIVE_PDF_READER_PREFIX = "http://drive.google.com/viewer?url=";
private static final String PDF_MIME_TYPE = "application/pdf";
private static final String HTML_MIME_TYPE = "text/html";
/**
* If a PDF reader is installed, download the PDF file and open it in a reader.
* Otherwise ask the user if he/she wants to view it in the Google Drive online PDF reader.<br />
* <br />
* <b>BEWARE:</b> This method
* @param context
* @param pdfUrl
* @return
*/
public static void showPDFUrl( final Context context, final String pdfUrl ) {
if ( isPDFSupported( context ) ) {
downloadAndOpenPDF(context, pdfUrl);
} else {
askToOpenPDFThroughGoogleDrive( context, pdfUrl );
}
}
/**
* Downloads a PDF with the Android DownloadManager and opens it with an installed PDF reader app.
* @param context
* @param pdfUrl
*/
@TargetApi(Build.VERSION_CODES.GINGERBREAD)
public static void downloadAndOpenPDF(final Context context, final String pdfUrl) {
// Get filename
final String filename = pdfUrl.substring( pdfUrl.lastIndexOf( "/" ) + 1 );
// The place where the downloaded PDF file will be put
final File tempFile = new File( context.getExternalFilesDir( Environment.DIRECTORY_DOWNLOADS ), filename );
if ( tempFile.exists() ) {
// If we have downloaded the file before, just go ahead and show it.
openPDF( context, Uri.fromFile( tempFile ) );
return;
}
// Show progress dialog while downloading
final ProgressDialog progress = ProgressDialog.show( context, context.getString( R.string.pdf_show_local_progress_title ), context.getString( R.string.pdf_show_local_progress_content ), true );
// Create the download request
DownloadManager.Request r = new DownloadManager.Request( Uri.parse( pdfUrl ) );
r.setDestinationInExternalFilesDir( context, Environment.DIRECTORY_DOWNLOADS, filename );
final DownloadManager dm = (DownloadManager) context.getSystemService( Context.DOWNLOAD_SERVICE );
BroadcastReceiver onComplete = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
if ( !progress.isShowing() ) {
return;
}
context.unregisterReceiver( this );
progress.dismiss();
long downloadId = intent.getLongExtra( DownloadManager.EXTRA_DOWNLOAD_ID, -1 );
Cursor c = dm.query( new DownloadManager.Query().setFilterById( downloadId ) );
if ( c.moveToFirst() ) {
int status = c.getInt( c.getColumnIndex( DownloadManager.COLUMN_STATUS ) );
if ( status == DownloadManager.STATUS_SUCCESSFUL ) {
openPDF( context, Uri.fromFile( tempFile ) );
}
}
c.close();
}
};
context.registerReceiver( onComplete, new IntentFilter( DownloadManager.ACTION_DOWNLOAD_COMPLETE ) );
// Enqueue the request
dm.enqueue( r );
}
/**
* Show a dialog asking the user if he wants to open the PDF through Google Drive
* @param context
* @param pdfUrl
*/
public static void askToOpenPDFThroughGoogleDrive( final Context context, final String pdfUrl ) {
new AlertDialog.Builder( context )
.setTitle( R.string.pdf_show_online_dialog_title )
.setMessage( R.string.pdf_show_online_dialog_question )
.setNegativeButton( R.string.pdf_show_online_dialog_button_no, null )
.setPositiveButton( R.string.pdf_show_online_dialog_button_yes, new OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
openPDFThroughGoogleDrive(context, pdfUrl);
}
})
.show();
}
/**
* Launches a browser to view the PDF through Google Drive
* @param context
* @param pdfUrl
*/
public static void openPDFThroughGoogleDrive(final Context context, final String pdfUrl) {
Intent i = new Intent( Intent.ACTION_VIEW );
i.setDataAndType(Uri.parse(GOOGLE_DRIVE_PDF_READER_PREFIX + pdfUrl ), HTML_MIME_TYPE );
context.startActivity( i );
}
/**
* Open a local PDF file with an installed reader
* @param context
* @param localUri
*/
public static final void openPDF(Context context, Uri localUri ) {
Intent i = new Intent( Intent.ACTION_VIEW );
i.setDataAndType( localUri, PDF_MIME_TYPE );
context.startActivity( i );
}
/**
* Checks if any apps are installed that supports reading of PDF files.
* @param context
* @return
*/
public static boolean isPDFSupported( Context context ) {
Intent i = new Intent( Intent.ACTION_VIEW );
final File tempFile = new File( context.getExternalFilesDir( Environment.DIRECTORY_DOWNLOADS ), "test.pdf" );
i.setDataAndType( Uri.fromFile( tempFile ), PDF_MIME_TYPE );
return context.getPackageManager().queryIntentActivities( i, PackageManager.MATCH_DEFAULT_ONLY ).size() > 0;
}
}
我终于能够修改butelo的代码,使用PDF .js打开Android文件系统中的任何PDF文件。代码可以在我的GitHub上找到
我所做的是修改pdffile.js读取HTML参数文件如下:
var url = getURLParameter('file');
function getURLParameter(name) {
return decodeURIComponent((new RegExp('[?|&]' + name + '=' + '([^&;]+?)(&|#|;|$)').exec(location.search)||[,""])[1].replace(/\+/g, '%20'))||null}
所以你需要做的就是像这样在index.html后面追加文件路径:
Uri path = Uri.parse(Environment.getExternalStorageDirectory().toString() + "/data/test.pdf");
webView.loadUrl("file:///android_asset/pdfviewer/index.html?file=" + path);
更新路径变量以指向Adroid文件系统中的有效PDF。
下载源代码在这里(显示PDF文件在我的android应用程序)
在你的年级中添加这个依赖项: 编译com.github.barteksc: android-pdf-viewer: 2.0.3
activity_main.xml
<RelativeLayout android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#ffffff"
xmlns:android="http://schemas.android.com/apk/res/android" >
<TextView
android:layout_width="match_parent"
android:layout_height="40dp"
android:background="@color/colorPrimaryDark"
android:text="View PDF"
android:textColor="#ffffff"
android:id="@+id/tv_header"
android:textSize="18dp"
android:gravity="center"></TextView>
<com.github.barteksc.pdfviewer.PDFView
android:id="@+id/pdfView"
android:layout_below="@+id/tv_header"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</RelativeLayout>
MainActivity.java
import android.app.Activity;
import android.database.Cursor;
import android.net.Uri;
import android.provider.OpenableColumns;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import com.github.barteksc.pdfviewer.PDFView;
import com.github.barteksc.pdfviewer.listener.OnLoadCompleteListener;
import com.github.barteksc.pdfviewer.listener.OnPageChangeListener;
import com.github.barteksc.pdfviewer.scroll.DefaultScrollHandle;
import com.shockwave.pdfium.PdfDocument;
import java.util.List;
public class MainActivity extends Activity implements OnPageChangeListener,OnLoadCompleteListener{
private static final String TAG = MainActivity.class.getSimpleName();
public static final String SAMPLE_FILE = "android_tutorial.pdf";
PDFView pdfView;
Integer pageNumber = 0;
String pdfFileName;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
pdfView= (PDFView)findViewById(R.id.pdfView);
displayFromAsset(SAMPLE_FILE);
}
private void displayFromAsset(String assetFileName) {
pdfFileName = assetFileName;
pdfView.fromAsset(SAMPLE_FILE)
.defaultPage(pageNumber)
.enableSwipe(true)
.swipeHorizontal(false)
.onPageChange(this)
.enableAnnotationRendering(true)
.onLoad(this)
.scrollHandle(new DefaultScrollHandle(this))
.load();
}
@Override
public void onPageChanged(int page, int pageCount) {
pageNumber = page;
setTitle(String.format("%s %s / %s", pdfFileName, page + 1, pageCount));
}
@Override
public void loadComplete(int nbPages) {
PdfDocument.Meta meta = pdfView.getDocumentMeta();
printBookmarksTree(pdfView.getTableOfContents(), "-");
}
public void printBookmarksTree(List<PdfDocument.Bookmark> tree, String sep) {
for (PdfDocument.Bookmark b : tree) {
Log.e(TAG, String.format("%s %s, p %d", sep, b.getTitle(), b.getPageIdx()));
if (b.hasChildren()) {
printBookmarksTree(b.getChildren(), sep + "-");
}
}
}
}
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