Pages in Flutter PDF library

2023-02-18 16:27| 来源: 网络整理| 查看: 265

Pages in Flutter PDF

10 Oct 20227 minutes to read

Adding a new page to the PDF document

The following code sample explains how to add a PdfPage to a PDF document. When multiple pages are added, the new page will always be added to the end of the document.

DART //Create a new PDF documentation PdfDocument document = PdfDocument(); //Create a new PDF page and draw the text document.pages.add().graphics.drawString( 'Hello World!!!', PdfStandardFont(PdfFontFamily.helvetica, 27), brush: PdfBrushes.darkBlue, bounds: const Rect.fromLTWH(170, 100, 0, 0)); //Save and dispose the PDF document File('Output.pdf').writeAsBytes(await document.save()); document.dispose(); Inserting pages in an existing document

You can insert an empty page at any location in the existing PDF document using the insert method. The following code sample explains the same.

DART //Loads an existing PDF document PdfDocument document = PdfDocument(inputBytes: File('input.pdf').readAsBytesSync()); //Inserts a new page at index 0 document.pages.insert(0); //Saves the document File('output.pdf').writeAsBytes(await document.save()); //Disposes the document document.dispose(); Adding margin to the PDF pages

You can add margin to all the PDF pages of a PDF document using the pageSettings property. The following code snippet explains the same.

DART //Create a new PDF documentation PdfDocument document = PdfDocument(); //Set margin for all the pages document.pageSettings.margins.all = 200; //Draw the text by adding page to the document document.pages.add().graphics.drawString( 'Hello World!!!', PdfStandardFont(PdfFontFamily.helvetica, 27), brush: PdfBrushes.darkBlue); //Save and dispose the PDF document List bytes =await document.save(); document.dispose(); Adding sections with different page settings

Flutter PDF supports adding sections with different page settings such as margins, orientation, rotate, size. You can add sections to a PDF document by using the PdfSection available in PdfDocument instance and create page settings to the PdfSection using the pageSettings property.

The following code snippet explains how to add more sections to a PDF document with different page settings.

DART //Create a PDF document PdfDocument document = PdfDocument(); //Set the font PdfFont font = PdfStandardFont(PdfFontFamily.helvetica, 14); //Section - 1 //Add section to the document PdfSection section = document.sections!.add(); //Create page settings to the section section.pageSettings.rotate = PdfPageRotateAngle.rotateAngle0; section.pageSettings.size = const Size(300, 400); //Draw simple text on the page section.pages.add().graphics.drawString('Rotated by 0 degrees', font, brush: PdfBrushes.black, bounds: const Rect.fromLTWH(20, 20, 0, 0)); //Section - 2 //Add section to the document section = document.sections!.add(); //Create page settings to the section section.pageSettings.rotate = PdfPageRotateAngle.rotateAngle90; section.pageSettings.size = const Size(300, 400); //Draw simple text on the page section.pages.add().graphics.drawString('Rotated by 90 degrees', font, brush: PdfBrushes.black, bounds: const Rect.fromLTWH(20, 20, 0, 0)); //Section - 3 //Add section to the document section = document.sections!.add(); //Create page settings to the section section.pageSettings.rotate = PdfPageRotateAngle.rotateAngle180; section.pageSettings.size = const Size(500, 200); //Draw simple text on the page section.pages.add().graphics.drawString('Rotated by 180 degrees', font, brush: PdfBrushes.black, bounds: const Rect.fromLTWH(20, 20, 0, 0)); //Section - 4 //Add section to the document section = document.sections!.add(); //Create page settings to the section section.pageSettings.rotate = PdfPageRotateAngle.rotateAngle270; section.pageSettings.size = const Size(300, 200); //Draw simple text on the page section.pages.add().graphics.drawString('Rotated by 270 degrees', font, brush: PdfBrushes.black, bounds: const Rect.fromLTWH(20, 20, 0, 0)); //Save and dispose the PDF document File('Output.pdf').writeAsBytes(await document.save()); document.dispose(); Get the number of pages from a PDF document

You can get the page count from the existing PDF document as shown in the following code sample.

DART //Loads an existing PDF document PdfDocument document = PdfDocument(inputBytes: File('input.pdf').readAsBytesSync()); //Gets the pages count int pageCount = document.pages.count; //Disposes the document document.dispose(); Rotating a PDF page

You can rotate a PDF page in the PDF document using the PdfPageRotateAngle enum as shown in the following code snippet.

DART //Create a PDF document PdfDocument document = PdfDocument(); //Add section to the document PdfSection section = document.sections!.add(); //Create page settings to the section section.pageSettings.rotate = PdfPageRotateAngle.rotateAngle180; section.pageSettings.size = PdfPageSize.a4; //Draw simple text on the page section.pages.add().graphics.drawString( 'Rotated by 180 degrees', PdfStandardFont(PdfFontFamily.helvetica, 14), brush: PdfBrushes.black, bounds: const Rect.fromLTWH(20, 20, 0, 0)); //Add section to the document section = document.sections!.add(); //Create page settings to the section section.pageSettings.rotate = PdfPageRotateAngle.rotateAngle270; section.pageSettings.size = PdfPageSize.a4; //Draw simple text on the page section.pages.add().graphics.drawString( 'Rotated by 270 degrees', PdfStandardFont(PdfFontFamily.helvetica, 14), brush: PdfBrushes.black, bounds: const Rect.fromLTWH(20, 20, 0, 0)); //Save and dispose the PDF document File('Output.pdf').writeAsBytes(await document.save()); document.dispose(); Removing pages from a document

You can remove the pages from the existing PDF document using the remove or removeAt method as shown in the following code sample.

DART //Loads an existing PDF document PdfDocument document = PdfDocument(inputBytes: File('input.pdf').readAsBytesSync()); //Gets the second page of the document PdfPage page = document.pages[1]; //Removes the second page from the document document.pages.remove(page); //Removes the first page from the document document.pages.removeAt(0); //Saves the document File('output.pdf').writeAsBytes(await document.save()); //Disposes the document document.dispose();

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