在PPT幻灯sql教程片中，可通过java基础教程添加形状python基础教程的方式，来实现c#教程类似水印的效教程果，可添加单一文本水印效果，即幻灯片中只有一个文本水印；也可以添加多行（平铺）文本水印效果，即幻灯片中以一定方式平铺排列多个文本水印效果。本文主要以C#程序代码为例介绍第二种水印添加方法，另附代码供参考。
程序环境
需引入以下程序集文件，如图：其中，Spire.Presentation.dll程序集，需下载安装至本地（也可以通过Nuget下载），这里使用的免费版。
.NET Framework 4.8
详细代码
【C#】
using Spire.Presentation;using Spire.Presentation.Drawing;using System;using System.Drawing;using System.Windows.Forms;namespace TextWatermark2{class Program{static void Main(string[] args){//加载PPT文档Presentation ppt = new Presentation();ppt.LoadFromFile("test.pptx");//获取需要添加的水印的幻灯片（第一张幻灯片）ISlide slide = ppt.Slides[0];//创建水印文本Font font = new Font("宋体", 20);String watermarkText = "内部资料";SizeF size = TextRenderer.MeasureText(watermarkText, font);//指定水印添加的起始坐标位置float x = 50;float y = 80;for (int i = 0; i < 4; i++){for (int j = 0; j < 4; j++){//绘制文本，设置文本格式RectangleF rect = new RectangleF(x, y, size.Width, size.Height);IAutoShape shape = slide.Shapes.AppendShape(Spire.Presentation.ShapeType.Rectangle, rect);shape.Fill.FillType = FillFormatType.None;shape.ShapeStyle.LineColor.Color = Color.White;shape.Rotation = -45;shape.Locking.SelectionProtection = true;shape.Line.FillType = FillFormatType.None;shape.TextFrame.Text = watermarkText;TextRange textRange = shape.TextFrame.TextRange;textRange.Fill.FillType = FillFormatType.Solid;textRange.Fill.SolidColor.Color = Color.FromArgb(120, Color.HotPink);textRange.EastAsianFont = new TextFont(font.Name);textRange.FontHeight = font.Size;x += (100 + size.Width);}x = 30;y += (100 + size.Height);}//保存文档ppt.SaveToFile("TextWatermark.pptx", FileFormat.Pptx);System.Diagnostics.Process.Start("TextWatermark.pptx");}}}
【】
Imports Spire.PresentationImports Spire.Presentation.DrawingImports System.DrawingImports System.Windows.FormsNamespace TextWatermark2Class ProgramPrivate Shared Sub Main(args As String())'加载PPT文档Dim ppt As New Presentation()ppt.LoadFromFile("test.pptx")'获取需要添加的水印的幻灯片（第一张幻灯片）Dim slide As ISlide = ppt.Slides(0)'创建水印文本Dim font As New Font("宋体", 20)Dim watermarkText As [String] = "内部资料"Dim size As SizeF = TextRenderer.MeasureText(watermarkText, font)'指定水印添加的起始坐标位置Dim x As Single = 50Dim y As Single = 80For i As Integer = 0 To 3For j As Integer = 0 To 3'绘制文本，设置文本格式Dim rect As New RectangleF(x, y, size.Width, size.Height)Dim shape As IAutoShape = slide.Shapes.AppendShape(Spire.Presentation.ShapeType.Rectangle, rect)shape.Fill.FillType = FillFormatType.Noneshape.ShapeStyle.LineColor.Color = Color.Whiteshape.Rotation = -45shape.Locking.SelectionProtection = Trueshape.Line.FillType = FillFormatType.Noneshape.TextFrame.Text = watermarkTextDim textRange As TextRange = shape.TextFrame.TextRangetextRange.Fill.FillType = FillFormatType.SolidtextRange.Fill.SolidColor.Color = Color.FromArgb(120, Color.HotPink)textRange.EastAsianFont = New TextFont(font.Name)textRange.FontHeight = font.Sizex += (100 + size.Width)Nextx = 30y += (100 + size.Height)Next'保存文档ppt.SaveToFile("TextWatermark.pptx", FileFormat.Pptx)System.Diagnostics.Process.Start("TextWatermark.pptx")End SubEnd ClassEnd Namespace
完成代码后，执行程序，生成结果文档。在结果文档中可查看水印添加效果，如下图：
其他关于C#操作PPT水印的方法可参考以下相关文章：
添加单一水印效果：C# 添加文本和图片水印到PPT
删除水印效果：C# 删除PPT中的水印
