打印 PDF - Android | 空无之境 = = 不忘初心，方得始终

需要将应用中生成的 PDF 直接打印出来

# 构建 PDFDocumentAdapter

	public class PDFDocumentAdapter extends PrintDocumentAdapter {

	private static final String TAG = "PDFDocumentAdapter";
	Context context;
	String pdfPath;
	File pdfFile;

	public PDFDocumentAdapter(Context context, String pdfPath) {
	this.context = context;
	this.pdfPath = pdfPath;
	}

	public PDFDocumentAdapter(Context context, File pdfFile) {
	this.context = context;
	this.pdfFile = pdfFile;
	}

	@Override
	public void onLayout(PrintAttributes oldAttributes, PrintAttributes newAttributes, CancellationSignal cancellationSignal, LayoutResultCallback callback, Bundle extras) {
	if (cancellationSignal.isCanceled()) {
	callback.onLayoutCancelled();
	InsToastUtil.showInBottom("取消打印");
	} else {
	PrintDocumentInfo.Builder builder =
	new PrintDocumentInfo.Builder(" file name");
	builder.setContentType(PrintDocumentInfo.CONTENT_TYPE_DOCUMENT)
	.setPageCount(PrintDocumentInfo.PAGE_COUNT_UNKNOWN)
	.build();
	callback.onLayoutFinished(builder.build(),
	!newAttributes.equals(oldAttributes));
	}
	}

	@Override
	public void onWrite(PageRange[] pages, ParcelFileDescriptor destination, CancellationSignal cancellationSignal, WriteResultCallback callback) {
	InputStream in = null;
	OutputStream out = null;
	try {
	File file;
	if (pdfFile != null) {
	file = pdfFile;
	}else {
	file = new File(pdfPath);
	}
	in = new FileInputStream(file);
	out = new FileOutputStream(destination.getFileDescriptor());

	byte[] buf = new byte[16384];
	int size;

	while ((size = in.read(buf)) >= 0
	&& !cancellationSignal.isCanceled()) {
	out.write(buf, 0, size);
	}

	if (cancellationSignal.isCanceled()) {
	callback.onWriteCancelled();
	InsToastUtil.showInBottom("取消打印");
	} else {
	callback.onWriteFinished(new PageRange[]{PageRange.ALL_PAGES});
	InsToastUtil.showInBottom("打印完成");
	}
	} catch (Exception e) {
	callback.onWriteFailed(e.getMessage());
	e.printStackTrace();
	} finally {
	try {
	if (in != null) {
	in.close();
	}
	if (out != null) {
	out.close();
	}
	} catch (IOException e) {
	e.printStackTrace();
	}
	}
	}
	}

# 打印

	/**
	* 调用系统打印功能打印 PDF
	*/
	private void print() {
	PrintManager printManager = (PrintManager) getSystemService(Context.PRINT_SERVICE);
	try {
	PrintDocumentAdapter printAdapter = new PDFDocumentAdapter(this, Static.getRootFolderPath() + File.separator + "test.pdf");
	printManager.print("Document", printAdapter, new PrintAttributes.Builder().build());
	} catch (Exception e) {
	e.printStackTrace();
	}
	}

需要手动添加打印机，即可打印，但是打印过程中存在纸张尺寸不匹配问题

Activity 打印