C# and .NET: PDF Content Clipping

The PdfPathContent or the character glyphs in the PdfTextContent can be set as a clipping path to clip subsequent content in the same content group.

The following example illustrates how to set up text and paths as clipping paths and use various clipping rules to crop subsequent images in the same content group.

Полный код

using System;
using SautinSoft.Pdf;
using System.IO;
using SautinSoft.Pdf.Content;

class Program
{
    /// <summary>
    /// Clipping.
    /// </summary>
    /// <remarks>
    /// Details: https://sautinsoft.com/products/pdf/help/net/developer-guide/pdf-content-formatting-clipping.php
    /// </remarks>
    static void Main()
    {
        // Before starting this example, please get a free 100-day trial key:
        // https://sautinsoft.com/start-for-free/

        // Apply the key here:
        // PdfDocument.SetLicense("...");

        using (var document = new PdfDocument())
        {
            var page = document.Pages.Add();

            // Add a new content group. Clipping is localized to the content group.
            var textGroup = page.Content.Elements.AddGroup();
            // Draw text in the content group.
            using (var formattedText = new PdfFormattedText())
            {
                formattedText.Font = new PdfFont("Helvetica", 96);

                formattedText.Append("Hello world!");

                textGroup.DrawText(formattedText, new PdfPoint(50, 700));
            }
            // Stroke all text elements in the group (to visualize their bounds) and set them as a clipping path.
            var format = textGroup.Format;
            format.Fill.IsApplied = false;
            format.Stroke.IsApplied = true;
            format.Clip.IsApplied = true;
            // Draw an image in the same content group as the text.
            // The image will be clipped to the text.
            var image = PdfImage.Load(@"..\..\..\JPEG2.jpg");
            textGroup.DrawImage(image, new PdfPoint(50, 700), new PdfSize(500, 100));

            // Add a new content group. Clipping is localized to the content group.
            var pathGroup = page.Content.Elements.AddGroup();
            // Add a diamond-like path to the content group.
            pathGroup.Elements.AddPath().BeginSubpath(50, 550).LineTo(300, 500).LineTo(550, 550).LineTo(300, 600).CloseSubpath();
            // Stroke all path elements in the group (to visualize their bounds) and set them as a clipping path.
            format = pathGroup.Format;
            format.Fill.IsApplied = false;
            format.Stroke.IsApplied = true;
            format.Clip.IsApplied = true;
            // Draw an image in the same content group as the diamond-like path.
            // The image will be clipped to the diamond-like path.
            pathGroup.DrawImage(image, new PdfPoint(50, 500), new PdfSize(500, 100));

            // Add a new content group. Clipping is localized to the content group.
            pathGroup = page.Content.Elements.AddGroup();
            // Add a star-like path to the content group.
            var path = pathGroup.Elements.AddPath();
            var center = new PdfPoint(150, 300);
            double radius = 100, cos1 = Math.Cos(Math.PI / 10), sin1 = Math.Sin(Math.PI / 10), cos2 = Math.Cos(Math.PI / 5), sin2 = Math.Sin(Math.PI / 5);
            // Create a five-point star.
            path.

            BeginSubpath(center.X - sin2 * radius, center.Y - cos2 * radius). // Start from the point in the bottom-left corner.
            LineTo(center.X + cos1 * radius, center.Y + sin1 * radius). // Continue to the point in the upper-right corner.
            LineTo(center.X - cos1 * radius, center.Y + sin1 * radius). // Continue to the point in the upper-left corner.
            LineTo(center.X + sin2 * radius, center.Y - cos2 * radius). // Continue to the point in the bottom-right corner.
            LineTo(center.X, center.Y + radius). // Continue to the point in the upper-center.
            CloseSubpath(); // End with the starting point.
                            // Stroke a path (to visualize its bounds) and set it as a clipping path using non-zero winding number rule.
            format = path.Format;
            format.Fill.IsApplied = false;
            format.Stroke.IsApplied = true;
            format.Clip.IsApplied = true;
            format.Clip.Rule = PdfFillRule.NonzeroWindingNumber;
            // Draw an image in the same content group as the star-like path.
            // The image will be clipped to the star-like path using non-zero winding number rule.
            pathGroup.DrawImage(image, new PdfPoint(50, 200), new PdfSize(200, 200));

            // Add a new content group. Clipping is localized to the content group.
            pathGroup = page.Content.Elements.AddGroup();
            // Clone a star-like path to the content group and move it down.
            path = pathGroup.Elements.AddClone(path);
            path.Subpaths.Transform(PdfMatrix.CreateTranslation(250, 0));
            // Set the clipping rule to even-odd.
            path.Format.Clip.Rule = PdfFillRule.EvenOdd;
            // Draw an image in the same content group as the star-like path.
            // The image will be clipped to the star-like path using the even-odd rule.
            pathGroup.DrawImage(image, new PdfPoint(300, 200), new PdfSize(200, 200));

            document.Save("Clipping.pdf");
        }

        System.Diagnostics.Process.Start(new System.Diagnostics.ProcessStartInfo("Clipping.pdf") { UseShellExecute = true });
    }
}

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Option Infer On

Imports System
Imports SautinSoft.Pdf
Imports System.IO
Imports SautinSoft.Pdf.Content

Friend Class Program
	''' <summary>
	''' Clipping.
	''' </summary>
	''' <remarks>
	''' Details: https://sautinsoft.com/products/pdf/help/net/developer-guide/pdf-content-formatting-clipping.php
	''' </remarks>
	Shared Sub Main()
		' Before starting this example, please get a free 100-day trial key:
		' https://sautinsoft.com/start-for-free/

		' Apply the key here:
		' PdfDocument.SetLicense("...");

		Using document = New PdfDocument()
			Dim page = document.Pages.Add()

			' Add a new content group. Clipping is localized to the content group.
			Dim textGroup = page.Content.Elements.AddGroup()
			' Draw text in the content group.
			Using formattedText = New PdfFormattedText()
				formattedText.Font = New PdfFont("Helvetica", 96)

				formattedText.Append("Hello world!")

				textGroup.DrawText(formattedText, New PdfPoint(50, 700))
			End Using
			' Stroke all text elements in the group (to visualize their bounds) and set them as a clipping path.
			Dim format = textGroup.Format
			format.Fill.IsApplied = False
			format.Stroke.IsApplied = True
			format.Clip.IsApplied = True
			' Draw an image in the same content group as the text.
			' The image will be clipped to the text.
			Dim image = PdfImage.Load("..\..\..\JPEG2.jpg")
			textGroup.DrawImage(image, New PdfPoint(50, 700), New PdfSize(500, 100))

			' Add a new content group. Clipping is localized to the content group.
			Dim pathGroup = page.Content.Elements.AddGroup()
			' Add a diamond-like path to the content group.
			pathGroup.Elements.AddPath().BeginSubpath(50, 550).LineTo(300, 500).LineTo(550, 550).LineTo(300, 600).CloseSubpath()
			' Stroke all path elements in the group (to visualize their bounds) and set them as a clipping path.
			format = pathGroup.Format
			format.Fill.IsApplied = False
			format.Stroke.IsApplied = True
			format.Clip.IsApplied = True
			' Draw an image in the same content group as the diamond-like path.
			' The image will be clipped to the diamond-like path.
			pathGroup.DrawImage(image, New PdfPoint(50, 500), New PdfSize(500, 100))

			' Add a new content group. Clipping is localized to the content group.
			pathGroup = page.Content.Elements.AddGroup()
			' Add a star-like path to the content group.
			Dim path = pathGroup.Elements.AddPath()
			Dim center = New PdfPoint(150, 300)
			Dim radius As Double = 100, cos1 As Double = Math.Cos(Math.PI / 10), sin1 As Double = Math.Sin(Math.PI / 10), cos2 As Double = Math.Cos(Math.PI / 5), sin2 As Double = Math.Sin(Math.PI / 5)
			' Create a five-point star.
			path.BeginSubpath(center.X - sin2 * radius, center.Y - cos2 * radius).LineTo(center.X + cos1 * radius, center.Y + sin1 * radius).LineTo(center.X - cos1 * radius, center.Y + sin1 * radius).LineTo(center.X + sin2 * radius, center.Y - cos2 * radius).LineTo(center.X, center.Y + radius).CloseSubpath() ' End with the starting point.
							' Stroke a path (to visualize its bounds) and set it as a clipping path using non-zero winding number rule.
			format = path.Format
			format.Fill.IsApplied = False
			format.Stroke.IsApplied = True
			format.Clip.IsApplied = True
			format.Clip.Rule = PdfFillRule.NonzeroWindingNumber
			' Draw an image in the same content group as the star-like path.
			' The image will be clipped to the star-like path using non-zero winding number rule.
			pathGroup.DrawImage(image, New PdfPoint(50, 200), New PdfSize(200, 200))

			' Add a new content group. Clipping is localized to the content group.
			pathGroup = page.Content.Elements.AddGroup()
			' Clone a star-like path to the content group and move it down.
			path = pathGroup.Elements.AddClone(path)
			path.Subpaths.Transform(PdfMatrix.CreateTranslation(250, 0))
			' Set the clipping rule to even-odd.
			path.Format.Clip.Rule = PdfFillRule.EvenOdd
			' Draw an image in the same content group as the star-like path.
			' The image will be clipped to the star-like path using the even-odd rule.
			pathGroup.DrawImage(image, New PdfPoint(300, 200), New PdfSize(200, 200))

			document.Save("Clipping.pdf")
		End Using

		System.Diagnostics.Process.Start(New System.Diagnostics.ProcessStartInfo("Clipping.pdf") With {.UseShellExecute = True})
	End Sub
End Class

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