【发布时间】：2015-05-14 10:08:48
【问题描述】：
我制作了一个 android 应用程序，用于使用连接到 wifi 的打印机打印 pdf 文件。我已经按照下面的代码进行了尝试，它只搜索设备，但什么也没发生。请查看我的代码并告诉我应该做哪些更改来解决我的问题。任何输入将不胜感激！
代码
public class MainActivity extends Activity {
public int pageHeight;
public int pageWidth;
public PdfDocument myPdfDocument;
public int totalpages = 4;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
public class MyPrintDocumentAdapter extends PrintDocumentAdapter {
Context context;
public MyPrintDocumentAdapter(Context context) {
this.context = context;
}
@SuppressLint("InlinedApi")
@Override
public void onLayout(PrintAttributes oldAttributes,
PrintAttributes newAttributes,
CancellationSignal cancellationSignal,
LayoutResultCallback callback, Bundle metadata) {
myPdfDocument = new PrintedPdfDocument(context, newAttributes);
pageHeight = newAttributes.getMediaSize().getHeightMils() / 1000 * 72;
pageWidth = newAttributes.getMediaSize().getWidthMils() / 1000 * 72;
if (cancellationSignal.isCanceled()) {
callback.onLayoutCancelled();
return;
}
if (totalpages > 0) {
PrintDocumentInfo.Builder builder = new PrintDocumentInfo.Builder(
"print_output.pdf").setContentType(
PrintDocumentInfo.CONTENT_TYPE_DOCUMENT).setPageCount(
totalpages);
PrintDocumentInfo info = builder.build();
callback.onLayoutFinished(info, true);
} else {
callback.onLayoutFailed("Page count is zero.");
}
}
@Override
public void onWrite(final PageRange[] pageRanges,
final ParcelFileDescriptor destination,
final CancellationSignal cancellationSignal,
final WriteResultCallback callback) {
for (int i = 0; i < totalpages; i++) {
if (pageInRange(pageRanges, i)) {
PageInfo newPage = new PageInfo.Builder(pageWidth,
pageHeight, i).create();
PdfDocument.Page page = myPdfDocument.startPage(newPage);
if (cancellationSignal.isCanceled()) {
callback.onWriteCancelled();
myPdfDocument.close();
myPdfDocument = null;
return;
}
drawPage(page, i);
myPdfDocument.finishPage(page);
}
}
try {
myPdfDocument.writeTo(new FileOutputStream(destination
.getFileDescriptor()));
} catch (IOException e) {
callback.onWriteFailed(e.toString());
return;
} finally {
myPdfDocument.close();
myPdfDocument = null;
}
callback.onWriteFinished(pageRanges);
}
private boolean pageInRange(PageRange[] pageRanges, int page) {
for (int i = 0; i < pageRanges.length; i++) {
if ((page >= pageRanges[i].getStart())
&& (page <= pageRanges[i].getEnd()))
return true;
}
return false;
}
private void drawPage(PdfDocument.Page page, int pagenumber) {
Canvas canvas = page.getCanvas();
pagenumber++; // Make sure page numbers start at 1
int titleBaseLine = 72;
int leftMargin = 54;
Paint paint = new Paint();
paint.setColor(Color.BLACK);
paint.setTextSize(40);
canvas.drawText("Test Print Document Page " + pagenumber,
leftMargin, titleBaseLine, paint);
paint.setTextSize(14);
canvas.drawText(
"This is some test content to verify that custom document printing works",
leftMargin, titleBaseLine + 35, paint);
if (pagenumber % 2 == 0)
paint.setColor(Color.RED);
else
paint.setColor(Color.GREEN);
PageInfo pageInfo = page.getInfo();
canvas.drawCircle(pageInfo.getPageWidth() / 2,
pageInfo.getPageHeight() / 2, 150, paint);
}
}
@SuppressLint("InlinedApi")
public void printDocument(View view) {
PrintManager printManager = (PrintManager) this
.getSystemService(Context.PRINT_SERVICE);
String jobName = this.getString(R.string.app_name) + " Document";
printManager.print(jobName, new MyPrintDocumentAdapter(this), null);
}
}
【问题讨论】：
标签： android printing android-wifi