Add multiple watermarks in presentation slides

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

namespace WatermarkDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a PPT document and load file
            Presentation presentation = new Presentation();
            presentation.LoadFromFile("Sample.pptx");

            //Get the size of the watermark string
            Font font = new Font("Arial", 20);
            String watermarkText = "E-iceblue";
            SizeF size = TextRenderer.MeasureText("E-iceblue", font);
            float x = 30;
            float y = 80;
            for (int i = 0; i < 3; i++)
            {
                for (int j = 0; j < 3; j++)
                {
                    //Define a rectangle range
                    RectangleF rect = new RectangleF(x, y, size.Width, size.Height);

                    //Add a rectangle shape with a defined range
                    IAutoShape shape = presentation.Slides[0].Shapes.AppendShape(Spire.Presentation.ShapeType.Rectangle, rect);

                    //Set the style of the shape
                    shape.Fill.FillType = FillFormatType.None;
                    shape.ShapeStyle.LineColor.Color = Color.White;
                    shape.Rotation = -45;
                    shape.Locking.SelectionProtection = true;
                    shape.Line.FillType = FillFormatType.None;

                    //Add text to the shape
                    shape.TextFrame.Text = watermarkText;
                    TextRange textRange = shape.TextFrame.TextRange;
                    //Set the style of the text range
                    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);
            }

            //Save the document
            presentation.SaveToFile("Watermark_result.pptx", FileFormat.Pptx2010);

        }
    }
}

Imports Spire.Presentation
Imports Spire.Presentation.Drawing
Imports System
Imports System.Drawing
Imports System.Windows.Forms

Namespace WatermarkDemo
    
    Class Program
        
        Private Shared Sub Main(ByVal args() As String)
            'Create a PPT document and load file
            Dim presentation As Presentation = New Presentation
            presentation.LoadFromFile("Sample.pptx")
            'Get the size of the watermark string
            Dim font As Font = New Font("Arial", 20)
            Dim watermarkText As String = "E-iceblue"
            Dim size As SizeF = TextRenderer.MeasureText("E-iceblue", font)
            Dim x As Single = 30
            Dim y As Single = 80
            Dim i As Integer = 0
            Do While (i < 3)
                Dim j As Integer = 0
                Do While (j < 3)
                    'Define a rectangle range
                    Dim rect As RectangleF = New RectangleF(x, y, size.Width, size.Height)
                    'Add a rectangle shape with a defined range
                    Dim shape As IAutoShape = presentation.Slides(0).Shapes.AppendShape(Spire.Presentation.ShapeType.Rectangle, rect)
                    'Set the style of the shape
                    shape.Fill.FillType = FillFormatType.None
                    shape.ShapeStyle.LineColor.Color = Color.White
                    shape.Rotation = -45
                    shape.Locking.SelectionProtection = true
                    shape.Line.FillType = FillFormatType.None
                    'Add text to the shape
                    shape.TextFrame.Text = watermarkText
                    Dim textRange As TextRange = shape.TextFrame.TextRange
                    'Set the style of the text range
                    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 = (x + (100 + size.Width))
                    j = (j + 1)
                Loop
                
                x = 30
                y = (y + (100 + size.Height))
                i = (i + 1)
            Loop
            
            'Save the document
            presentation.SaveToFile("Watermark_result.pptx", FileFormat.Pptx2010)
        End Sub
    End Class
End Namespace