Add text to slide

VSTO
Spire.Presentation
Download Sample Code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;
using PowerPoint = Microsoft.Office.Interop.PowerPoint;
using Office = Microsoft.Office.Core;
using System.Drawing;

namespace VSTO
{
    public partial class ThisAddIn
    {
        private void ThisAddIn_Startup(object sender, System.EventArgs e)
        {
            //Create empty presentation
            PowerPoint.Presentation ppt = this.Application.Presentations.Add();

            //Add a blank slide
            PowerPoint.Slide slide = ppt.Slides.Add(1, PowerPoint.PpSlideLayout.ppLayoutBlank);

            //Add a textbox
            PowerPoint.Shape shape = slide.Shapes.AddTextbox(Office.MsoTextOrientation.msoTextOrientationHorizontal, 100, 100, 300, 200);
            
            //Add text
            PowerPoint.TextRange textRange = shape.TextFrame.TextRange;
            textRange.Text = "Spire.Presentation for .NET";
           
            //Set text style
            textRange.Font.Color.RGB = 0x00CC3333;
            textRange.Font.Bold = Office.MsoTriState.msoTrue;
            textRange.Font.Size = 20;

            //Save the file
            ppt.SaveAs("AddedText.pptx");
        }

        private void ThisAddIn_Shutdown(object sender, System.EventArgs e)
        {
        }

        #region VSTO generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InternalStartup()
        {
            this.Startup += new System.EventHandler(ThisAddIn_Startup);
            this.Shutdown += new System.EventHandler(ThisAddIn_Shutdown);
        }
        
        #endregion
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Spire.Presentation;
using System.Drawing;
using Spire.Presentation.Drawing;


namespace Spire.Presentation
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create ppt document
            Presentation ppt = new Presentation();
            
            //Add a shape
            IAutoShape shape = ppt.Slides[0].Shapes.AppendShape(ShapeType.Rectangle, new Rectangle(100, 100, 300, 200));

            //Make the shape invisible 
            shape.Fill.FillType = FillFormatType.None;
            shape.Line.FillType = FillFormatType.None;
            
            //Add text
            TextRange textRange=shape.TextFrame.TextRange;
            textRange.Text="Spire.Presentation for .NET";
            
            //Set text style           
            textRange.Format.Fill.FillType = FillFormatType.Solid;
            textRange.Format.Fill.SolidColor.Color = Color.Blue ;
            textRange.FontHeight=20;
            textRange.Format.IsBold = TriState.True;
            
            //Save and Launch
            ppt.SaveToFile("AddedText.pptx", FileFormat.Pptx2010);
            System.Diagnostics.Process.Start("AddedText.pptx");
            
        }
    }
}

AddText.zip