C# 处理PPT水印（一）——添加水印效果（文字水印、图片水印）

对文档添加水印可以有效声明和保护文档，是保护重要文件的方式之一。在PPT文档中同样也可以设置水印，包括文本水印和图片水印，本文将讲述如何通过Spire.Presentation for .NET来对PPT添加水印，下载安装Free Spire.Presentationfor .NET后，添加引用dll文件，参考下面的操作步骤，完成水印添加。

1.添加文本水印

步骤一：初始化Presentation类实例，并加载文档

Presentation ppt = new Presentation();
ppt.LoadFromFile(@"C:UsersAdministratorDesktopsample.pptx", FileFormat.Pptx2010);

步骤二：初始化一个Font类实例，并实例化字体格式

Font stringFont = new Font("Arial", 90);
Size size = TextRenderer.MeasureText("内部资料", stringFont);

步骤三：绘制一个shape并指定大小、填充颜色、边框颜色和旋转角度

RectangleF rect = new RectangleF((ppt.SlideSize.Size.Width - size.Width) / 2, (ppt.SlideSize.Size.Height - size.Height) / 2, size.Width, size.Height);
IAutoShape shape = ppt.Slides[0].Shapes.AppendShape(Spire.Presentation.ShapeType.Rectangle, rect);
shape.Fill.FillType = FillFormatType.None;
shape.ShapeStyle.LineColor.Color = Color.White;
shape.Rotation = -45;

步骤四：设定形状属性为保护属性

shape.Locking.SelectionProtection = true;
shape.Line.FillType = FillFormatType.None;

步骤五：设置文本大小、颜色

shape.TextFrame.Text = "内部资料";
TextRange textRange = shape.TextFrame.TextRange;
textRange.Fill.FillType = Spire.Presentation.Drawing.FillFormatType.Solid;
textRange.Fill.SolidColor.Color = Color.FromArgb(120, Color.Gray);
textRange.FontHeight = 45;

步骤六：保存文档

ppt.SaveToFile("TextWatermark.pptx", FileFormat.Pptx2010);

完成以上代码步骤后，调试运行项目程序，生成文件（可在该项目文件中bin>Debug中查看），如下图所示：

 

全部代码：

using System;
using System.Text;
using Spire.Presentation;
using System.Drawing;
using Spire.Presentation.Drawing;
using System.Windows.Forms;

namespace InsertWatermark_PPT
{
    class Program
    {
        static void Main(string[] args)
        {
            //初始化一个Presentation类实例并加载文档
            Presentation ppt = new Presentation();
            ppt.LoadFromFile(@"C:UsersAdministratorDesktopsample.pptx", FileFormat.Pptx2010);

            //初始化一个Font类字体实例并实例化字体格式
            Font stringFont = new Font("Arial", 90);
            Size size = TextRenderer.MeasureText("内部资料", stringFont);

            //绘制一个Shape并指定大小、填充颜色、边框颜色和旋转度
            RectangleF rect = new RectangleF((ppt.SlideSize.Size.Width - size.Width) / 2, (ppt.SlideSize.Size.Height - size.Height) / 2, size.Width, size.Height);
            IAutoShape shape = ppt.Slides[0].Shapes.AppendShape(Spire.Presentation.ShapeType.Rectangle, rect);
            shape.Fill.FillType = FillFormatType.None;
            shape.ShapeStyle.LineColor.Color = Color.White;
            shape.Rotation = -45;

            //设定形状属性为保护属性
            shape.Locking.SelectionProtection = true;
            shape.Line.FillType = FillFormatType.None;

            //设置文本大小、颜色
            shape.TextFrame.Text = "内部资料";
            TextRange textRange = shape.TextFrame.TextRange;
            textRange.Fill.FillType = Spire.Presentation.Drawing.FillFormatType.Solid;
            textRange.Fill.SolidColor.Color = Color.FromArgb(150, Color.LightBlue);
            textRange.FontHeight = 90;

            //保存文档
            ppt.SaveToFile("TextWatermark.pptx", FileFormat.Pptx2010);
        }
    }

2.添加图片水印

步骤一：初始化一个Presentation类实例并加载文档

Presentation ppt = new Presentation();
ppt.LoadFromFile(@"C:UsersAdministratorDesktopsample.pptx", FileFormat.Pptx2010);

步骤二: 为第一张幻灯片设置背景图片类型和样式

ppt.Slides[0].SlideBackground.Type = Spire.Presentation.Drawing.BackgroundType.Custom;
ppt.Slides[0].SlideBackground.Fill.FillType = FillFormatType.Picture;
ppt.Slides[0].SlideBackground.Fill.PictureFill.FillType = PictureFillType.Stretch;

步骤三：加载图片并为第一张幻灯片设置水印

Image img = Image.FromFile(@"C:UsersAdministratorDesktopimages1.jpg");
IImageData image = ppt.Images.Append(img);
ppt.Slides[0].SlideBackground.Fill.PictureFill.Picture.EmbedImage = image;

步骤四：保存文档

 ppt.SaveToFile("ImageWatermark1.pptx", FileFormat.Pptx2010);

全部代码：

using System;
using System.Drawing;
using Spire.Presentation;
using Spire.Presentation.Drawing;

namespace ImageWatermark_PPT
{
    class Program
    {
        static void Main(string[] args)
        {
            //初始化一个Presentation类实例并加载文档
            Presentation ppt = new Presentation();
            ppt.LoadFromFile(@"C:UsersAdministratorDesktopsample.pptx", FileFormat.Pptx2010);

            //为第一张幻灯片设置背景图片类型和样式
            ppt.Slides[0].SlideBackground.Type = Spire.Presentation.Drawing.BackgroundType.Custom;
            ppt.Slides[0].SlideBackground.Fill.FillType = FillFormatType.Picture;
            ppt.Slides[0].SlideBackground.Fill.PictureFill.FillType = PictureFillType.Stretch;

            //加载图片并为第一张幻灯片设置水印效果
            Image img = Image.FromFile(@"C:UsersAdministratorDesktopimages1.jpg");
            IImageData image = ppt.Images.Append(img);
            ppt.Slides[0].SlideBackground.Fill.PictureFill.Picture.EmbedImage = image;

            //保存文档
            ppt.SaveToFile("ImageWatermark1.pptx", FileFormat.Pptx2010);
        }
    }
}

以上是对PPT添加水印的代码操作，希望该方法能提供帮助，感谢阅读！