Java 如何在 Android 中呈现 PDF
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How to render PDF in Android
提问by Mikey
In my application I will receive a byte stream and convert it to a pdf file in the phone memory. How do I render that to a pdf? And show it on an activity?
在我的应用程序中，我将接收一个字节流并将其转换为手机内存中的 pdf 文件。我如何将其呈现为pdf？并在活动中展示它？
采纳答案by Tim Kryger
Some phones (like the Nexus One) come with a version of Quickofficepre-installed so it may be as easy as sending the appropriate Intent once you've saved the file to the SD card.
某些手机（例如 Nexus One）预装了Quickoffice版本，因此一旦您将文件保存到 SD 卡，就可以像发送适当的 Intent 一样简单。
public class OpenPdf extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button button = (Button) findViewById(R.id.OpenPdfButton);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
File file = new File("/sdcard/example.pdf");
if (file.exists()) {
Uri path = Uri.fromFile(file);
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(path, "application/pdf");
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
try {
startActivity(intent);
}
catch (ActivityNotFoundException e) {
Toast.makeText(OpenPdf.this,
"No Application Available to View PDF",
Toast.LENGTH_SHORT).show();
}
}
}
});
}
}
回答by Shankar Agarwal
public class MyPdfViewActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
WebView mWebView=new WebView(MyPdfViewActivity.this);
mWebView.getSettings().setJavaScriptEnabled(true);
mWebView.getSettings().setPluginsEnabled(true);
mWebView.loadUrl("https://docs.google.com/gview?embedded=true&url="+LinkTo);
setContentView(mWebView);
}
}
回答by Zephyr
For the local pdf files, you can render them through the third party libraries. for example, use the MuPDF library, its supported file types include PDF, PNG and JPEG.
对于本地pdf文件，您可以通过第三方库进行渲染。例如，使用MuPDF 库，其支持的文件类型包括 PDF、PNG 和 JPEG。
One shortcoming of MuPDF is that it uses native library to fulfill the target, so it won't be easy to port the application on BlackBerry platform later.
MuPDF 的一个缺点是它使用本机库来实现目标，因此以后将应用程序移植到黑莓平台上并不容易。
回答by ben75
Android-Lollipop (api 21) introduce a new API : PdfRenderer
Android-Lollipop (api 21) 引入了一个新的 API：PdfRenderer
This API allows you to create a Bitmap from a page in a PDF document.
此 API 允许您从 PDF 文档中的页面创建位图。
Shortly :
不久：
get a seekable file descriptor from your pdf document :
ParcelFileDescriptor fd = ParcelFileDescriptor.open(file, ParcelFileDescriptor.MODE_READ_ONLY)create the PdfRenderer
PdfRenderer renderer = new PdfRenderer(fd);prepare the Bitmap
Bitmap bitmap = Bitmap.createBitmap(WIDTH, HEIGHT, Bitmap.Config.ARGB_4444);get the PdfRenderer.Pageto render
PdfRenderer.Page page = renderer.openPage(pageIndex);render the page on the prepared bitmap
page.render(bitmap, null, null, PdfRenderer.Page.RENDER_MODE_FOR_DISPLAY);now you can do what you want with the bitmap.
- note that the 2 null args may allow you to clip some portion in the page and perform a transformation (using a Matrix) of the clip
- there is another rendering mode : RENDER_MODE_FOR_PRINT. If you need this mode there are some guidelines to use it properly : here are the details.
从您的 pdf 文档中获取可查找的文件描述符：
ParcelFileDescriptor fd = ParcelFileDescriptor.open(file, ParcelFileDescriptor.MODE_READ_ONLY)创建 PdfRenderer
PdfRenderer renderer = new PdfRenderer(fd);准备位图
Bitmap bitmap = Bitmap.createBitmap(WIDTH, HEIGHT, Bitmap.Config.ARGB_4444);获取要呈现的PdfRenderer.Page
PdfRenderer.Page page = renderer.openPage(pageIndex);在准备好的位图上渲染页面
page.render(bitmap, null, null, PdfRenderer.Page.RENDER_MODE_FOR_DISPLAY);现在你可以用位图做你想做的事了。
- 请注意，2 个空参数可能允许您剪辑页面中的某些部分并执行剪辑的转换（使用Matrix）
- 还有另一种渲染模式：RENDER_MODE_FOR_PRINT。如果您需要此模式，有一些正确使用它的指南：这里是详细信息。
回答by Alecs
This library is simple and works well: Android Pdf Viewerhttps://github.com/barteksc/AndroidPdfViewer
这个库很简单而且运行良好： Android Pdf Viewer https://github.com/barteksc/AndroidPdfViewer
Old Reply...
旧回复...
I think that Joan Zapata give us the better and simple solution:
https://github.com/JoanZapata/android-pdfview
I assure you that it works!
我认为 Joan Zapata 为我们提供了更好更简单的解决方案：
https://github.com/JoanZapata/android-pdfview
我向你保证它有效！
回答by Nermeen
To open a pdf from a byte array, you can use RadaeePDF, you can do the following into your activity:
要从字节数组打开 pdf，您可以使用RadaeePDF，您可以在您的活动中执行以下操作：
private PDFReader m_vPDF = null;
private Document doc = new Document();
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
Global.Init(this);
m_vPDF = new PDFReader(this);
doc.Close();
int ret = m_doc.OpenMem(data, password);
switch( ret )
{
case -1://need input password
finish();
break;
case -2://unknown encryption
finish();
break;
case -3://damaged or invalid format
finish();
break;
case -10://access denied or invalid file path
finish();
break;
case 0://succeeded, and continue
break;
default://unknown error
finish();
break;
}
m_vPDF.open(doc);
setContentView( m_vPDF );
}
