C# 绘制PDF图形——基本图形、自定义图形、色彩透明度

时间：2021-06-28 06:45:40

引言

在PDF中我们可以通过C#程序代码来添加非常丰富的元素来呈现我们想要表达的内容，如绘制表格、文字，添加图形、图像等等。在本篇文章中，我将介绍如何在PDF中绘制图形，并设置图形属性的操作。

文章中将分以下要点进行介绍：

1. 绘制基本图形（线条、椭圆、圆形、矩形、三角形）

2. 绘制自定义图形

3. 绘制图形并设置图形透明度

所需工具：Spire.PDF for .NET 4.0

提示：安装后，直接引用安装路径下Bin文件夹中的dll文件到项目程序中即可。

【示例1】绘制基本图形

C#

步骤1：新建一个PDF文档，添加页，添加画笔、画刷

            //新建一个PDF文档，添加页

            PdfDocument doc = new PdfDocument();

            PdfPageBase page = doc.Pages.Add();

            //设置画笔和画刷

            PdfPen pen = new PdfPen(PdfBrushes.Black, 1f);

            PdfBrush brush1 = PdfBrushes.RosyBrown;

            PdfBrush brush2 = PdfBrushes.Goldenrod;

步骤2：绘制圆形、矩形、线段、三角形

            //绘入矩形（此处通过设置值来绘制成正方形）

            page.Canvas.DrawRectangle(pen, brush1, new Rectangle(new Point(, ), new Size(, )));

            //绘入椭圆（此处通过设置值来绘制成圆形）

            page.Canvas.DrawEllipse(pen, brush2, , , , );

            //绘入线段

            page.Canvas.DrawLine(pen, new PointF(, ), new PointF(, ));

            //绘入多边形（此处绘制成三角形）

            PointF p1 = new PointF(, );

            PointF p2 = new PointF(, );

            PointF p3 = new PointF(, );

            PointF[] points = new PointF[] { p1, p2, p3 };

            page.Canvas.DrawPolygon(pen, points);

步骤3：保存文档

            //保存并打开文档

            doc.SaveToFile("基本图形.pdf");

            System.Diagnostics.Process.Start("基本图形.pdf");

全部代码

using Spire.Pdf;

using Spire.Pdf.Graphics;

using System.Drawing;

namespace DrawRectangle_PDF

{

    class Program

    {

        static void Main(string[] args)

        {

            //新建一个PDF文档，添加页

            PdfDocument doc = new PdfDocument();

            PdfPageBase page = doc.Pages.Add();

            //设置画笔和画刷

            PdfPen pen = new PdfPen(PdfBrushes.Black, 1f);

            PdfBrush brush1 = PdfBrushes.RosyBrown;

            PdfBrush brush2 = PdfBrushes.Goldenrod;

            //绘入矩形（此处通过设置值来绘制成正方形）

            page.Canvas.DrawRectangle(pen, brush1, new Rectangle(new Point(, ), new Size(, )));

            //绘入椭圆（此处通过设置值来绘制成圆形）

            page.Canvas.DrawEllipse(pen, brush2, , , , );

            //绘入线段

            page.Canvas.DrawLine(pen, new PointF(, ), new PointF(, ));

            //绘入多边形（此处绘制成三角形）

            PointF p1 = new PointF(, );

            PointF p2 = new PointF(, );

            PointF p3 = new PointF(, );

            PointF[] points = new PointF[] { p1, p2, p3 };

            page.Canvas.DrawPolygon(pen, points);

            //保存并打开文档

            doc.SaveToFile("基本图形.pdf");

            System.Diagnostics.Process.Start("基本图形.pdf");

        }

    }

}

效果图：

C# 绘制PDF图形——基本图形、自定义图形、色彩透明度

【示例2】绘制自定义图形

步骤1：创建pdf文档，调用方法DrawStar()绘制自定义图形，并保存

            //新建一个PDF文档，添加页

            PdfDocument doc = new PdfDocument();

            PdfPageBase page = doc.Pages.Add();

            //调用DrawStar()方法绘入五角星图形

            DrawStar(page);

            //保存并打开文档

            doc.SaveToFile("自定义图形.pdf");

            System.Diagnostics.Process.Start("自定义图形.pdf");

步骤2：自定义DrawStar()方法绘制几个不同样式的五角星

 private static void DrawStar(PdfPageBase page)

        {

            //设置五角星的5个顶点坐标

            PointF[] points = new PointF[];

            for (int i = ; i < points.Length; i++)

            {

                float x = (float)Math.Cos(i *  * Math.PI / );

                float y = (float)Math.Sin(i *  * Math.PI / );

                points[i] = new PointF(x, y);

            }

            //创建PdfPath类，在顶点之间添加线段组成五角星

            PdfPath path = new PdfPath();

            path.AddLine(points[], points[]);

            path.AddLine(points[], points[]);

            path.AddLine(points[], points[]);

            path.AddLine(points[], points[]);

            path.AddLine(points[], points[]);

            //保存画布状态

            PdfGraphicsState state = page.Canvas.Save();

            //实例化画笔和画刷1、画刷2

            PdfPen pen = new PdfPen(Color.DeepSkyBlue, 0.02f);

            PdfBrush brush1 = new PdfSolidBrush(Color.PaleGreen);

            PdfBrush brush2 = new PdfSolidBrush(Color.Bisque);

            //将坐标放大40倍

            page.Canvas.ScaleTransform(40f, 40f);

            //平移坐标

            page.Canvas.TranslateTransform(1f, 1.5f);

            //绘入第一个五角星

            page.Canvas.DrawPath(pen, path);

            //平移坐标并在新的位置绘入第二个五角星

            page.Canvas.TranslateTransform(2f, 0f);

            path.FillMode = PdfFillMode.Alternate;

            page.Canvas.DrawPath(pen, brush1, path);

            //平移坐标并在新的位置绘入第三个五角星

            page.Canvas.TranslateTransform(2f, 0f);

            path.FillMode = PdfFillMode.Winding;

            page.Canvas.DrawPath(pen, brush2, path);

            //实例化画刷3，平移坐标并在新的位置绘入第四个五角星

            PdfLinearGradientBrush brush3

                = new PdfLinearGradientBrush(new PointF(-, ), new PointF(, ), Color.OrangeRed, Color.Yellow);

            page.Canvas.TranslateTransform(-4f, 2f);

            path.FillMode = PdfFillMode.Alternate;

            page.Canvas.DrawPath(pen, brush3, path);

            //实例化画刷4，平移坐标并在新的位置绘入第五个五角星

            PdfRadialGradientBrush brush4

                = new PdfRadialGradientBrush(new PointF(0f, 0f), 0f, new PointF(0f, 0f), 1f, Color.Orchid, Color.LightBlue);

            page.Canvas.TranslateTransform(2f, 0f);

            path.FillMode = PdfFillMode.Winding;

            page.Canvas.DrawPath(pen, brush4, path);

            //实例化画刷5，平移坐标并在新的位置绘入第六个五角星

            PdfTilingBrush brush5 = new PdfTilingBrush(new RectangleF(, , 4f, 4f));

            brush5.Graphics.DrawRectangle(brush3, , , 4f, 4f);

            page.Canvas.TranslateTransform(2f, 0f);

            path.FillMode = PdfFillMode.Winding;

            page.Canvas.DrawPath(pen, brush5, path);

            //再次保存画布状态

            page.Canvas.Restore(state);

        }

全部代码：

using Spire.Pdf;

using Spire.Pdf.Graphics;

using System;

using System.Drawing;

namespace DrawCustomGraphics_PDF

{

    class Program

    {

        static void Main(string[] args)

        {

            //新建一个PDF文档，添加页

            PdfDocument doc = new PdfDocument();

            PdfPageBase page = doc.Pages.Add();

            //调用DrawStar()方法绘入五角星图形

            DrawStar(page);

            //保存并打开文档

            doc.SaveToFile("自定义图形.pdf");

            System.Diagnostics.Process.Start("自定义图形.pdf");

        }

        //自定义DrawStar方法绘制几个不同样式的五角星

        private static void DrawStar(PdfPageBase page)

        {

            //设置五角星的5个顶点坐标

            PointF[] points = new PointF[];

            for (int i = ; i < points.Length; i++)

            {

                float x = (float)Math.Cos(i *  * Math.PI / );

                float y = (float)Math.Sin(i *  * Math.PI / );

                points[i] = new PointF(x, y);

            }

            //创建PdfPath类，在顶点之间添加线段组成五角星

            PdfPath path = new PdfPath();

            path.AddLine(points[], points[]);

            path.AddLine(points[], points[]);

            path.AddLine(points[], points[]);

            path.AddLine(points[], points[]);

            path.AddLine(points[], points[]);

            //保存画布状态

            PdfGraphicsState state = page.Canvas.Save();

            //实例化画笔和画刷1、画刷2

            PdfPen pen = new PdfPen(Color.DeepSkyBlue, 0.02f);

            PdfBrush brush1 = new PdfSolidBrush(Color.PaleGreen);

            PdfBrush brush2 = new PdfSolidBrush(Color.Bisque);

            //将坐标放大40倍

            page.Canvas.ScaleTransform(40f, 40f);

            //平移坐标

            page.Canvas.TranslateTransform(1f, 1.5f);

            //绘入第一个五角星

            page.Canvas.DrawPath(pen, path);

            //平移坐标并在新的位置绘入第二个五角星

            page.Canvas.TranslateTransform(2f, 0f);

            path.FillMode = PdfFillMode.Alternate;

            page.Canvas.DrawPath(pen, brush1, path);

            //平移坐标并在新的位置绘入第三个五角星

            page.Canvas.TranslateTransform(2f, 0f);

            path.FillMode = PdfFillMode.Winding;

            page.Canvas.DrawPath(pen, brush2, path);

            //实例化画刷3，平移坐标并在新的位置绘入第四个五角星

            PdfLinearGradientBrush brush3

                = new PdfLinearGradientBrush(new PointF(-, ), new PointF(, ), Color.OrangeRed, Color.Yellow);

            page.Canvas.TranslateTransform(-4f, 2f);

            path.FillMode = PdfFillMode.Alternate;

            page.Canvas.DrawPath(pen, brush3, path);

            //实例化画刷4，平移坐标并在新的位置绘入第五个五角星

            PdfRadialGradientBrush brush4

                = new PdfRadialGradientBrush(new PointF(0f, 0f), 0f, new PointF(0f, 0f), 1f, Color.Orchid, Color.LightBlue);

            page.Canvas.TranslateTransform(2f, 0f);

            path.FillMode = PdfFillMode.Winding;

            page.Canvas.DrawPath(pen, brush4, path);

            //实例化画刷5，平移坐标并在新的位置绘入第六个五角星

            PdfTilingBrush brush5 = new PdfTilingBrush(new RectangleF(, , 4f, 4f));

            brush5.Graphics.DrawRectangle(brush3, , , 4f, 4f);

            page.Canvas.TranslateTransform(2f, 0f);

            path.FillMode = PdfFillMode.Winding;

            page.Canvas.DrawPath(pen, brush5, path);

            //再次保存画布状态

            page.Canvas.Restore(state);

        }

    }

}

效果图：

C# 绘制PDF图形——基本图形、自定义图形、色彩透明度

【示例3】设置色彩透明度

步骤1：新建一个PDF文档，添加页

            PdfDocument doc = new PdfDocument();

            PdfPageBase page = doc.Pages.Add();

步骤2：初始化一个PdfSeparationColorSpace的对象，用于创建基本色，并将基本色透明度设置为1

            PdfSeparationColorSpace cs1 = new PdfSeparationColorSpace("MySpotColor", Color.DarkGreen);

            PdfSeparationColorSpace cs2 = new PdfSeparationColorSpace("MySpotColor", Color.Yellow);

            PdfSeparationColorSpace cs3 = new PdfSeparationColorSpace("MySpotColor", Color.DeepPink);

            PdfSeparationColor color1 = new PdfSeparationColor(cs1, 1f);

            PdfSeparationColor color2 = new PdfSeparationColor(cs2, 1f);

            PdfSeparationColor color3 = new PdfSeparationColor(cs3, 1f);

步骤3：根据颜色创建画刷

            PdfSolidBrush brush1 = new PdfSolidBrush(color1);

            PdfSolidBrush brush2 = new PdfSolidBrush(color2);

            PdfSolidBrush brush3 = new PdfSolidBrush(color3);

步骤4：绘入图形及文字，应用色彩透明度到图形

           //绘入图形及文字并着色

            page.Canvas.DrawPie(brush1, , , , , , );

            page.Canvas.DrawPie(brush2, , , , , , );

            page.Canvas.DrawPie(brush3, , , , , , );

            page.Canvas.DrawString("透明度=1.0", new PdfTrueTypeFont(new Font("Arial Unicode MS", 10f), true), brush1, new PointF(, ));

            //将基本色透明度设置为0.5,并绘入图形及文字

            color1 = new PdfSeparationColor(cs1, 0.5f);

            brush1 = new PdfSolidBrush(color1);

            page.Canvas.DrawPie(brush1, , , , , , );

            color2 = new PdfSeparationColor(cs2, 0.5f);

            brush2 = new PdfSolidBrush(color2);

            page.Canvas.DrawPie(brush2, , , , , , );

            color3 = new PdfSeparationColor(cs3, 0.5f);

            brush3 = new PdfSolidBrush(color3);

            page.Canvas.DrawPie(brush3, , , , , , );

            page.Canvas.DrawString("透明度=0.5", new PdfTrueTypeFont(new Font("Arial Unicode MS", 10f), true), brush1, new PointF(, ));

            //将基本色透明度设置为0.25,并绘入图形及文字

            color1 = new PdfSeparationColor(cs1, 0.25f);

            brush1 = new PdfSolidBrush(color1);

            page.Canvas.DrawPie(brush1, , , , , , );

            color2 = new PdfSeparationColor(cs2, 0.25f);

            brush2 = new PdfSolidBrush(color2);

            page.Canvas.DrawPie(brush2, , , , , , );

            color3 = new PdfSeparationColor(cs3, 0.25f);

            brush3 = new PdfSolidBrush(color3);

            page.Canvas.DrawPie(brush3, , , , , , );

            page.Canvas.DrawString("透明度=0.25", new PdfTrueTypeFont(new Font("Arial Unicode MS", 10f), true), brush1, new PointF(, ));

步骤5：保存文档

            doc.SaveToFile("设置透明度.pdf");

            System.Diagnostics.Process.Start("设置透明度.pdf");

全部代码：

using Spire.Pdf;

using Spire.Pdf.ColorSpace;

using Spire.Pdf.Graphics;

using System.Drawing;

namespace CrearteSpotColor_PDF

{

    class Program

    {

        static void Main(string[] args)

        {

            //新建一个PDF文档，添加页

            PdfDocument doc = new PdfDocument();

            PdfPageBase page = doc.Pages.Add();

            //初始化一个PdfSeparationColorSpace的对象，用于创建基本色

            PdfSeparationColorSpace cs1 = new PdfSeparationColorSpace("MySpotColor", Color.DarkGreen);

            PdfSeparationColorSpace cs2 = new PdfSeparationColorSpace("MySpotColor", Color.Yellow);

            PdfSeparationColorSpace cs3 = new PdfSeparationColorSpace("MySpotColor", Color.DeepPink);

            //将基本色透明度设置为1

            PdfSeparationColor color1 = new PdfSeparationColor(cs1, 1f);

            PdfSeparationColor color2 = new PdfSeparationColor(cs2, 1f);

            PdfSeparationColor color3 = new PdfSeparationColor(cs3, 1f);

            //根据颜色创建画刷

            PdfSolidBrush brush1 = new PdfSolidBrush(color1);

            PdfSolidBrush brush2 = new PdfSolidBrush(color2);

            PdfSolidBrush brush3 = new PdfSolidBrush(color3);

            //绘入图形及文字并着色

            page.Canvas.DrawPie(brush1, , , , , , );

            page.Canvas.DrawPie(brush2, , , , , , );

            page.Canvas.DrawPie(brush3, , , , , , );

            page.Canvas.DrawString("透明度=1.0", new PdfTrueTypeFont(new Font("Arial Unicode MS", 10f), true), brush1, new PointF(, ));

            //将基本色透明度设置为0.5,并绘入图片及文字

            color1 = new PdfSeparationColor(cs1, 0.5f);

            brush1 = new PdfSolidBrush(color1);

            page.Canvas.DrawPie(brush1, , , , , , );

            color2 = new PdfSeparationColor(cs2, 0.5f);

            brush2 = new PdfSolidBrush(color2);

            page.Canvas.DrawPie(brush2, , , , , , );

            color3 = new PdfSeparationColor(cs3, 0.5f);

            brush3 = new PdfSolidBrush(color3);

            page.Canvas.DrawPie(brush3, , , , , , );

            page.Canvas.DrawString("透明度=0.5", new PdfTrueTypeFont(new Font("Arial Unicode MS", 10f), true), brush1, new PointF(, ));

            //将基本色透明度设置为0.25,并绘入图片及文字

            color1 = new PdfSeparationColor(cs1, 0.25f);

            brush1 = new PdfSolidBrush(color1);

            page.Canvas.DrawPie(brush1, , , , , , );

            color2 = new PdfSeparationColor(cs2, 0.25f);

            brush2 = new PdfSolidBrush(color2);

            page.Canvas.DrawPie(brush2, , , , , , );

            color3 = new PdfSeparationColor(cs3, 0.25f);

            brush3 = new PdfSolidBrush(color3);

            page.Canvas.DrawPie(brush3, , , , , , );

            page.Canvas.DrawString("透明度=0.25", new PdfTrueTypeFont(new Font("Arial Unicode MS", 10f), true), brush1, new PointF(, ));

            //保存并打开文档

            doc.SaveToFile("设置透明度.pdf");

            System.Diagnostics.Process.Start("设置透明度.pdf");

        }

    }

}

效果图：

C# 绘制PDF图形——基本图形、自定义图形、色彩透明度

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