PdfiumViewer组件扩展(Pdfium.Net.Free)--PDF操作

合集 - PdfiumViewer组件扩展(Pdfium.Net.Free)(16)

1.PdfiumViewer组件扩展(Pdfium.Net.Free)--概述2024-01-042.PdfiumViewer组件扩展(Pdfium.Net.Free)--快速入门2024-01-253.PdfiumViewer组件扩展(Pdfium.Net.Free)--PDF预览器框选2024-01-254.PdfiumViewer组件扩展(Pdfium.Net.Free)--打开大文件处理2024-01-255.PdfiumViewer组件扩展(Pdfium.Net.Free)--加载字体2024-01-296.PdfiumViewer组件扩展(Pdfium.Net.Free)--创建字符子集2024-01-297.PdfiumViewer组件扩展(Pdfium.Net.Free)--添加文本2024-01-298.PdfiumViewer组件扩展(Pdfium.Net.Free)--添加图片2024-01-309.PdfiumViewer组件扩展(Pdfium.Net.Free)--添加水印2024-02-0210.PdfiumViewer组件扩展(Pdfium.Net.Free)--删除或编辑pdf内容2024-01-31

11.PdfiumViewer组件扩展(Pdfium.Net.Free)--PDF操作2024-02-02

12.PdfiumViewer组件扩展(Pdfium.Net.Free)--签名2024-01-3113.PdfiumViewer组件扩展(Pdfium.Net.Free)--注解2024-01-3114.PdfiumViewer组件扩展(Pdfium.Net.Free)--可视化编辑pdf2024-04-0715.什么是转换矩阵以及如何使用它2024-02-2416.Pdfium.Net.Free 添加 bblanchon.PDFium nuget方式02-11

收起

项目地址：

Pdfium.Net：https://github.com/1000374/Pdfium.Net.Free

PdfiumViewer：https://github.com/1000374/PdfiumViewer

Pdfium.Net.Free 支持

• .NETFramework 4.0

• .NETFramework 4.5

• .NETStandard 2.0

• .Net8.0

可以和PdfiumViewer.Free共同使用预览、编辑pdf，也可以直接引用Pdfium.Net.Free 操作pdf，Pdfium.Net.Free封装了现有Pdfium的函数，实现了部分操作pdf的功能，部分功能等待后续~~

Pdfium.Net支持对PDF操作：

• 转成图片
• 拆分
• 合并
• 插入
• 替换
• 删除
• 旋转
• 导出缩略图
• 多页合并成一页

1.转成图片

1.基于GDI+下：

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/// <summary> /// Renders a page of the PDF document to the provided graphics instance. <see cref="Platforms.Windows"/> /// </summary> /// <param name="graphics">Graphics instance to render the page on.</param> /// <param name="dpiX">Horizontal DPI.</param> /// <param name="dpiY">Vertical DPI.</param> /// <param name="bounds">Bounds to render the page in.</param> /// <param name="rotation"><see cref="FpdfRotation"/></param> /// <param name="flags">Flags used to influence the rendering.</param> public void Render(Graphics graphics, float dpiX, float dpiY, Rectangle bounds, FpdfRotation rotation, RenderFlags flags)

示例代码：

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var pathPdf = "./Pdfium.NetTests/resources/annotation_highlight_long_content.pdf"; using (var doc = PdfDocument.Load(new MemoryStream(File.ReadAllBytes(pathPdf)))) {     var page0 = doc.Pages[0];     Image image = new Bitmap((int)page0.Width, (int)page0.Height);     var g = Graphics.FromImage(image);     page0.Render(g, g.DpiX, g.DpiY, new Rectangle(         AdjustDpi(g.DpiX, 0),         AdjustDpi(g.DpiY, 0),         AdjustDpi(g.DpiX, image.Width),         AdjustDpi(g.DpiY, image.Height)),FpdfRotation.Rotate0,RenderFlags.None);     image.Save("./Pdfium.NetTests/Render.png"); }

　　

2.不基于GDI+

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/// <summary> /// Renders a page of the PDF document to an image. /// </summary> /// <param name="width">Width of the rendered image.</param> /// <param name="height">Height of the rendered image.</param> /// <param name="dpiX">Horizontal DPI.</param> /// <param name="dpiY">Vertical DPI.</param> /// <param name="rotate">Rotation.</param> /// <param name="flags">Flags used to influence the rendering.</param> /// <returns>The rendered image.</returns> public Image Render(int width, int height, float dpiX, float dpiY, FpdfRotation rotate, RenderFlags flags)

　

示例代码：

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var pathPdf = "./Pdfium.NetTests/resources/annotation_highlight_long_content.pdf"; using (var doc = PdfDocument.Load(new MemoryStream(File.ReadAllBytes(pathPdf))))     for (int i = 0; i < doc.PageCount; i++)     {         using (var image = doc.Pages[i].Render((int)doc.Pages[i].Width * 4 / 3, (int)doc.Pages[i].Height * 4 / 3, 96, 96, FpdfRotation.Rotate0, RenderFlags.Annotations | RenderFlags.CorrectFromDpi))         {           }     }

　　

3.不基于GDI+ 获取指定区域

区域坐标可通过框选获取，详情查看此

Pdfium.Net.Free 一个免费的Pdfium的 .net包装器--PDF预览器框选

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/// <summary> /// Renders the page. /// </summary> /// <param name="width"> /// The full width of the rendered image in px. /// If 0, width will be calculated from height using the correct apsect ratio. /// Height and width can not be both set to zero. /// </param> /// <param name="height"> /// The full wiheightth of the rendered image in px. /// If 0, height will be calculated from height using the correct apsect ratio. /// Height and width can not be both set to zero. /// </param> /// <param name="clipX">X value of the start point of the clipping area</param> /// <param name="clipY">Y value of the start point of the clipping area</param> /// <param name="clipWidth">Width of the clip area</param> /// <param name="clipHeight">Height of the clip area</param> /// <param name="dpiX">DPI to render page. If set, width and height will accept percentage.</param> /// <param name="dpiY">DPI to render page. If set, width and height will accept percentage.</param> /// <param name="rotate">Specify rotation.</param> /// <param name="flags">Specify flags.</param> /// <returns>Image from the page.</returns> public Image Render(int width, int height, int clipX, int clipY, int clipWidth, int clipHeight, float dpiX, float dpiY, FpdfRotation rotate, RenderFlags flags)

　　

示例代码：

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var pathPdf = "./Pdfium.NetTests/resources/annotation_highlight_long_content.pdf"; using (var doc = PdfDocument.Load(new MemoryStream(File.ReadAllBytes(pathPdf))))     for (int i = 0; i < doc.PageCount; i++)     {         using (var image = doc.Pages[i].Render(             (int)doc.Pages[i].Width,             (int)doc.Pages[i].Height,             16, // x of the top/left of clipping rectangle            283, // y of the top/left point of clipping rectangle            555, // width of clipping reactangle            316, // height of clipping reactangle            0,//DPIx            0,//DPIy            FpdfRotation.Rotate0, // no rotation            RenderFlags.None // no render flags                                ))         {             Assert.AreEqual(555, image.Width);         }     }

　　

2.拆分

可使用封装好的函数直接获取每一页后保存

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var pathPdf = "./Pdfium.NetTests/resources/viewer_ref.pdf"; using (var doc = PdfDocument.Load(new MemoryStream(File.ReadAllBytes(pathPdf)))) {     for (int i = 0; i < doc.PageCount; i++)     {         var doci = doc.GetPDFPage(i);     } }

 

也可直接使用doc对象保存

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var pathPdf = "./Pdfium.NetTests/resources/viewer_ref.pdf"; using (var doc = PdfDocument.Load(new MemoryStream(File.ReadAllBytes(pathPdf)))) {     for (int i = 0; i < doc.PageCount; i++)     {         var newDocument = PdfDocument.CreateNew();         if (newDocument.Pages.Add(doc, i))         {             newDocument.Save($"./Pdfium.NetTests/AddTest{i}.pdf");         }     } }

　　

3.合并

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var pathPdf = "./Pdfium.NetTests/resources/viewer_ref.pdf"; using (var doc = PdfDocument.Load(new MemoryStream(File.ReadAllBytes(pathPdf)))) using (var doc1 = PdfDocument.Load(new MemoryStream(File.ReadAllBytes(pathPdf)))) {     doc.MergePDF(doc1); }

4.插入

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var pathPdf = "./Pdfium.NetTests/resources/viewer_ref.pdf"; var pathPdf1 = "./Pdfium.NetTests/resources/zero_length_stream.pdf";   using (var doc = PdfDocument.Load(new MemoryStream(File.ReadAllBytes(pathPdf)))) using (var doc1 = PdfDocument.Load(new MemoryStream(File.ReadAllBytes(pathPdf1)))) {     doc.ImportPage(doc1, 1); }

　　

5.替换　　

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var pathPdf = "./Pdfium.NetTests/resources/viewer_ref.pdf"; var pathPdf1 = "./Pdfium.NetTests/resources/zero_length_stream.pdf";   using (var doc = PdfDocument.Load(new MemoryStream(File.ReadAllBytes(pathPdf)))) using (var doc1 = PdfDocument.Load(new MemoryStream(File.ReadAllBytes(pathPdf1)))) {     doc.DeletePage(1);     doc.ImportPage(doc1, 1); }

　

6.删除

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var pathPdf = "./Pdfium.NetTests/resources/viewer_ref.pdf"; using (var doc = PdfDocument.Load(new MemoryStream(File.ReadAllBytes(pathPdf)))) {      doc.DeletePage(0); }

　　

也可通过以下删除

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var pathPdf = "./Pdfium.NetTests/resources/viewer_ref.pdf"; using (var doc = PdfDocument.Load(new MemoryStream(File.ReadAllBytes(pathPdf)))) {     doc.Pages.RemoveAt(0); }

　　

7.旋转

pdf可进行360度旋转 具体看枚举值FpdfRotation

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/// <summary> /// Specifies the rotation of pages shown in the PDF renderer. /// </summary> public enum FpdfRotation {     /// <summary>     /// Rotates the output 0 degrees.     /// </summary>     Rotate0,     /// <summary>     /// Rotates the output 90 degrees.     /// </summary>     Rotate90,     /// <summary>     /// Rotates the output 180 degrees.     /// </summary>     Rotate180,     /// <summary>     /// Rotates the output 270 degrees.     /// </summary>     Rotate270 }

示例：

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var pathPdf = "./Pdfium.NetTests/resources/viewer_ref.pdf"; using (var doc = PdfDocument.Load(new MemoryStream(File.ReadAllBytes(pathPdf)))) {     doc.RotatePage(0,FpdfRotation.Rotate90); }

　　

8.导出缩略图

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var pathPdf = "./Pdfium.NetTests/resources/simple_thumbnail.pdf"; using (var doc = PdfDocument.Load(new MemoryStream(File.ReadAllBytes(pathPdf))))     for (int i = 0; i < doc.PageCount; i++)     {         var image = doc.Pages[i].RenderThumbnail();     }

　　

9.多页合并成一页

函数声明：

• num_pages_on_x_axis ：横向几页合并成一页默认2

• num_pages_on_y_axis ：纵向几页合并成一页默认1

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/// <summary> /// Create a new document from |src_doc|.  The pages of |src_doc| will be combined to provide |num_pages_on_x_axis x num_pages_on_y_axis| pages per |output_doc| page. /// number of pages per page = num_pages_on_x_axis * num_pages_on_y_axis /// </summary> /// <param name="output_width">The output page width in PDF "user space" units.</param> /// <param name="output_height">The output page height in PDF "user space" units.</param> /// <param name="num_pages_on_x_axis">The number of pages on X Axis.</param> /// <param name="num_pages_on_y_axis">The number of pages on Y Axis.</param> /// <returns>A handle to the created document, or NULL on failure.</returns> public PdfDocument ImportNPagesToOne(float output_width, float output_height, uint num_pages_on_x_axis = 2, uint num_pages_on_y_axis = 1)

　　

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var pathPdf = "./Pdfium.NetTests/resources/rectangles_multi_pages.pdf";  using (var doc = PdfDocument.Load(new MemoryStream(File.ReadAllBytes(pathPdf))))  {      using (var doc1 = doc.ImportNPagesToOne(612 * 2, 792)) {}  }