如何打印密码保护的PDF在android?

Question

我正在使用以下代码打印pdf，该代码适用于正常的pdf，但使用密码保护的pdf会崩溃。有什么方法可以打印有密码保护的PDF文件或防止应用程序崩溃吗?即使在try-catch块中调用print()，应用程序也会崩溃。

异常:

java.lang.RuntimeException: 
at android.print.PrintManager$PrintDocumentAdapterDelegate$MyHandler.handleMessage (PrintManager.java:1103)
at android.os.Handler.dispatchMessage (Handler.java:106)
at android.os.Looper.loop (Looper.java:246)
at android.app.ActivityThread.main (ActivityThread.java:8506)
at java.lang.reflect.Method.invoke (Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:602)
at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:1139)

导致异常的代码:

val printManager = this.getSystemService(Context.PRINT_SERVICE) as PrintManager
val jobName = this.getString(R.string.app_name) + " Document"
try{
printManager.print(jobName, pda, null)
}
catch(ex:RuntimeException)
{
Toast.makeText(this,"Can't print pdf file",Toast.LENGTH_SHORT).show()
}

PrintDocumentAdapter.kt

var pda: PrintDocumentAdapter = object : PrintDocumentAdapter() {

override fun onWrite(
pages: Array<PageRange>,
destination: ParcelFileDescriptor,
cancellationSignal: CancellationSignal,
callback: WriteResultCallback
) {
var input: InputStream? = null
var output: OutputStream? = null
try {
input = uri?.let { contentResolver.openInputStream(it) }

output = FileOutputStream(destination.fileDescriptor)
val buf = ByteArray(1024)
var bytesRead: Int
if (input != null) {
while (input.read(buf).also { bytesRead = it } > 0) {
output.write(buf, 0, bytesRead)
}
}
callback.onWriteFinished(arrayOf(PageRange.ALL_PAGES))
} catch (ee: FileNotFoundException) {
//Code to Catch FileNotFoundException
} catch (e: Exception) {
//Code to Catch exception
} finally {
try {
input!!.close()
output!!.close()
} catch (e: IOException) {
e.printStackTrace()
}
}
}

override fun onLayout(
oldAttributes: PrintAttributes,
newAttributes: PrintAttributes,
cancellationSignal: CancellationSignal,
callback: LayoutResultCallback,
extras: Bundle
) {
if (cancellationSignal.isCanceled) {
callback.onLayoutCancelled()
return
}
val pdi = PrintDocumentInfo.Builder("Name of file")
.setContentType(PrintDocumentInfo.CONTENT_TYPE_DOCUMENT).build()
callback.onLayoutFinished(pdi, true)
}
}

或者如果不可能，那么如何从pdf中删除密码。

Answer 1

pdfView.fromAsset(String)
.pages(0, 2, 1, 3, 3, 3) // all pages are displayed by default
.enableSwipe(true) // allows to block changing pages using swipe
.swipeHorizontal(false)
.enableDoubletap(true)
.defaultPage(0)
// allows to draw something on the current page, usually visible in the middle of the screen
.onDraw(onDrawListener)
// allows to draw something on all pages, separately for every page. Called only for visible pages
.onDrawAll(onDrawListener)
.onLoad(onLoadCompleteListener) // called after document is loaded and starts to be rendered
.onPageChange(onPageChangeListener)
.onPageScroll(onPageScrollListener)
.onError(onErrorListener)
.onPageError(onPageErrorListener)
.onRender(onRenderListener) // called after document is rendered for the first time
// called on single tap, return true if handled, false to toggle scroll handle visibility
.onTap(onTapListener)
.onLongPress(onLongPressListener)
.enableAnnotationRendering(false) // render annotations (such as comments, colors or forms)
.password(null)
.scrollHandle(null)
.enableAntialiasing(true) // improve rendering a little bit on low-res screens
// spacing between pages in dp. To define spacing color, set view background
.spacing(0)
.autoSpacing(false) // add dynamic spacing to fit each page on its own on the screen
.linkHandler(DefaultLinkHandler)
.pageFitPolicy(FitPolicy.WIDTH) // mode to fit pages in the view
.fitEachPage(false) // fit each page to the view, else smaller pages are scaled relative to largest page.
.pageSnap(false) // snap pages to screen boundaries
.pageFling(false) // make a fling change only a single page like ViewPager
.nightMode(false) // toggle night mode
.load();

您试过更新"密码"吗?行吗?

Answer 2

不需要生成没有密码的pdf来打印。正如你所说的，你正在使用barteksc:android-pdf-viewer来查看pdf，它使用PDfium来渲染pdf，它有一个方法来从方法中渲染位图。

void getBitmaps() {
ImageView iv = (ImageView) findViewById(R.id.imageView);
ParcelFileDescriptor fd = ...;
int pageNum = 0;
PdfiumCore pdfiumCore = new PdfiumCore(context);
try {
PdfDocument pdfDocument = pdfiumCore.newDocument(fd);
pdfiumCore.openPage(pdfDocument, pageNum);
int width = pdfiumCore.getPageWidthPoint(pdfDocument, pageNum);
int height = pdfiumCore.getPageHeightPoint(pdfDocument, pageNum);
// ARGB_8888 - best quality, high memory usage, higher possibility of OutOfMemoryError
// RGB_565 - little worse quality, twice less memory usage
Bitmap bitmap = Bitmap.createBitmap(width, height,
Bitmap.Config.RGB_565);
pdfiumCore.renderPageBitmap(pdfDocument, bitmap, pageNum, 0, 0,
width, height);
//if you need to render annotations and form fields, you can use
//the same method above adding 'true' as last param
iv.setImageBitmap(bitmap);
printInfo(pdfiumCore, pdfDocument);
pdfiumCore.closeDocument(pdfDocument); // important!
} catch(IOException ex) {
ex.printStackTrace();
}
}

将这些位图存储在arraylist中，并使用android print框架打印它们