65.9K
CodeProject is changing. Read more.
Home

Make a Countdown Timer Add-in for Powerpoint - Part 2

Wayne Jin
starIconstarIconstarIconstarIcon
emptyStarIcon
starIcon

4.33/5 (3 votes)

Oct 12, 2022

CPOL

2 min read

viewsIcon

6001

downloadIcon

154

A walkthrough to create a VSTO CountDown Timer Add-in for Powerpoint

Download

Introduction

Recently, I wrote an article titled "Make a Countdown Timer Add-in for Powerpoint - Part 1". In Part 1, I used only VBA to create the add-in. Now in Part 2, I am going to use C# to create a VSTO add-in for Powerpoint.

Background

Visual Studio Tools for Office (VSTO) is a set of development tools available in the form of a Visual Studio add-in (project templates) and a runtime. It greatly simplifies the development process of Office Add-in. I am going to build the same CountDown Timer add-in with Visual Studio 2019 now.

Using the Code

  1. First let's create a new project:

    Please select "Powerpoint VSTO Add-in" project template, and C#, click "Next".

  2. Key in project name as "CountDown", keep the rest as default, then click "Create".

  3. Below is the skeleton created by the system:

  4. Add Ribbon (Visual Designer):

    Select "CountDown" Project in the Solution Explorer Pane, right click the mouse, on Pop up menu, select "Add\New Items".

    Select Add Ribbon (Visual Designer) and click Add.

    Note: Alternatively, you can also select Add Ribbon (XML) and click Add, XML has more features to play around, however there is no GUI for XML, personally I prefer Visual Designer.

  5. Insert 8 buttons into the Ribbon:

  6. Customize 8 buttons:

  7. In the end, all the 8 buttons shall look like below:

  8. Add AboutBox:

  9. Customize AboutBox as per below: 

    using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Linq;
using System.Reflection;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace CountDown
{
    partial class frmAboutBox : Form
    {	    
        public frmAboutBox()
        {
            InitializeComponent();
            this.Text = String.Format("About {0}", AssemblyTitle);
            this.labelProductName.Text = AssemblyProduct;
            this.labelVersion.Text = String.Format("Version {0}", AssemblyVersion);
            this.labelCopyright.Text = AssemblyCopyright;
            this.labelCompanyName.Text = AssemblyCompany;
            this.textBoxDescription.Text = "This Utility is for user 
                        to add \"CountDown Timers\" in PPT slides.\n" +
                "It allows users to add any number of timers with 
                 different preset duration.\n" + 
                "How to use:\n" + 
                " 1. Find \"CountDown Tab\", then click on 
                     \"Install CountDown\"\n" + 
                " 2. Select a slide and click on \"Add Timer\"\n" + 
                " 3. To play the timer, in \"Slide Show\" mode, 
                     click on the Timer, it will start to count down, 
                     click again it reset.\n" + 
                " 4. To change the preset duration & TextEffect, 
                     select a Timer on a slide, then click on \"Edit Timer\"\n" + 
                " 5. To delete a timer, select a Timer on a slide, 
                     then click on \"Del Timer\"";
        }
    }
}
  10. Add frmDuration:

  11. Customize frmDuration as per below: 

    using Microsoft.VisualBasic;
using System;
using System.IO;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace CountDown
{
    public partial class frmDuration : Form
    {
        private int nDuration;
        public int Duration
        {
            get
            {
                return nDuration;
            }
            set
            {
                nDuration = value;
                cboDuration.Text = value.ToString();
            }
        }

        private int nTextEffectIdx;
        public int TextEffectIdx
        {
            get
            {
                return nTextEffectIdx;
            }
            set
            {
                nTextEffectIdx = value;
                cboTextEffect.Text = value.ToString();
            }
        }

        private string sSoundEffect;
        public string SoundEffect
        {
            get
            {
                return sSoundEffect;
            }
            set
            {
                sSoundEffect = value;
                cboSoundEffect.Text = value;
            }
        }

        public frmDuration()
        {
            InitializeComponent();

            ResetComboBox(cboDuration);
            ResetComboBox(cboSoundEffect);
            ResetComboBox(cboTextEffect);
        }

        private void ResetComboBox(ComboBox oComboBox)
        {
            if (oComboBox.Name == "cboDuration")
            {
                oComboBox.Items.Clear();
                oComboBox.Items.Add("1");
                oComboBox.Items.Add("2");
                oComboBox.Items.Add("3");
                oComboBox.Items.Add("4");
                oComboBox.Items.Add("5");
                oComboBox.Items.Add("10");
                oComboBox.Items.Add("15");
                oComboBox.Items.Add("30");
                oComboBox.Items.Add("45");
                oComboBox.Items.Add("60");
                oComboBox.Items.Add("90");
                oComboBox.Items.Add("120");
                oComboBox.Items.Add("150");
                oComboBox.Items.Add("180");
                oComboBox.Items.Add("210");
                oComboBox.Items.Add("240");
                oComboBox.Items.Add("300");
                oComboBox.SelectedIndex = 4;
            }
            else if (oComboBox.Name == "cboSoundEffect")
            {
                oComboBox.Items.Clear();
                oComboBox.Items.Add("None");

                string sFileName;
                string sExt;
                string sFolderPath = "c:\\Windows\\Media\\";
                foreach (string sPath in Directory.GetFiles(sFolderPath))
                {
                    sFileName = Path.GetFileName(sPath);
                    sExt = Path.GetExtension(sPath).ToLower();
                    if (sExt == ".wav" || sExt == ".mid" || sExt == ".mp3")
                    {
                        if (Strings.InStr(sFileName, "Windows") == 0)
                        {
                            oComboBox.Items.Add(sFileName);
                        }
                    }
                }
                oComboBox.SelectedIndex = 0;
            }
            else if (oComboBox.Name == "cboTextEffect")
            {
                int i;
                oComboBox.Items.Clear();
                for (i = 0; i <= 49; i++)
                    oComboBox.Items.Add(Strings.Format(i, "00"));
                oComboBox.SelectedIndex = 29;
                nTextEffectIdx = 29;
            }
        }

        private void btnOK_Click(object sender, EventArgs e)
        {
            bool bIsDurationValid = false;
            try
            {
                int nNum =int.Parse(cboDuration.Text);
                bIsDurationValid = true;
            }
            catch (Exception)
            {
                bIsDurationValid = false;
            }

            if (bIsDurationValid & cboSoundEffect.Text != "" & 
                                   cboTextEffect.Text != "")
            {
                nDuration = int.Parse(cboDuration.Text);
                sSoundEffect = cboSoundEffect.Text;
                nTextEffectIdx = int.Parse(cboTextEffect.Text);
                this.DialogResult = DialogResult.OK;
                this.Hide();
            }
            else
            {
                string sErrMsg = "";
                if (!bIsDurationValid)
                {
                    sErrMsg += "Please select a valid duration" + 
                                Constants.vbCrLf;
                }
                if (cboSoundEffect.Text == "")
                {
                    sErrMsg += "Please select a SoundEffect" + Constants.vbCrLf;
                }
                if (cboTextEffect.Text == "")
                {
                    sErrMsg += "Please select a TextEffect" + Constants.vbCrLf;
                }
                Interaction.MsgBox(sErrMsg);
            }
        }

        private void cboDuration_TextChanged(object sender, EventArgs e)
        {
            int nValue;
            if (int.TryParse(cboDuration.Text, out nValue))
            {
                nDuration = nValue;
            }
        }

        private void cboSoundEffect_SelectionChangeCommitted
                (object sender, EventArgs e)
        {
            if (this.cboSoundEffect.Text != "None")
            {
                Utilities.ReloadMediaFile(this.cboSoundEffect.Text);
                Utilities.StartPlayingMediaFile();
                Interaction.MsgBox("Click to OK to stop playing sound effect");
                Utilities.ReloadMediaFile(sSoundEffect);
            }
        }

        private void cboTextEffect_SelectedIndexChanged
                     (object sender, EventArgs e)
        {
            int nIdx = int.Parse(cboTextEffect.Text);
            Image oImage = ImageList1.Images[nIdx];
            picDisplay.Image = oImage;
        }
    }
}
  12. Add Utilities static Class:

    Add all the utilities functions in this class as static, so they can be used without declaration.

    Below are some code snippet of the Utilities class, please refer to the source code for full version.

    using Microsoft.Office.Interop.PowerPoint;
using Microsoft.Vbe.Interop;
using Microsoft.VisualBasic;
using System;
using System.IO;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;

namespace CountDown
{
    public static class Utilities
    {
        public const string m_sCountDownShapeName = "CountDown";
        public const string m_sCountDownInstPrjName = "CountDownAddinInstPrj";

        public const string sCountDownShapeName = "CountDown";
        public const string sCountDownSymbolShapeName = "CountDownSymbol";
        public const string sCountDownGroupName = "grpCountDown";
        public const string sCountDownInstPrjName = "CountDownAddinInstPrj";
        public const string sCountDownFontName = "Amasis MT Pro Black";
        public const string sCountDownSymbolFontName = 
                            "Segoe UI Emoji"; //"WingDings"


        [DllImport("winmm.dll", EntryPoint = "mciSendStringA")]
        private static extern long mciSendString
                (string lpstrCommand, string lpstrReturnString, 
                 long uReturnLength, long hwndCallback);

        private static bool bSoundIsPlaying;

        public static bool IsAccess2VBOMTrusted()
        {
            bool bIsTrusted;
            string sName;
            try
            {
                sName = Globals.ThisAddIn.Application.
                        ActivePresentation.VBProject.Name;
                bIsTrusted = true;

            }
            catch (Exception)
            {
                bIsTrusted = false;
            }
            return bIsTrusted;
        }

        public static bool IsCountDownInstalled()
        {
            return IsComponentExist("modCountDown");
        }

        public static bool IsProjectProtected()
        {
            bool bIsProtected = false;
            if (Globals.ThisAddIn.Application.VBE.
            ActiveVBProject.Protection == vbext_ProjectProtection.vbext_pp_locked)
            {
                bIsProtected = true;
            }
            return bIsProtected;
        }

        public static bool IsComponentExist(string sModuleName)
        {
            bool bExist = false;
            foreach (VBComponent oComponent in Globals.ThisAddIn.
                     Application.VBE.ActiveVBProject.VBComponents)
            {
                if (oComponent.Name == sModuleName)
                {
                    bExist = true;
                    break;
                }
            }
            return bExist;
        }
    }
}
  13. Add AddInUtilities Class for COM interface: 
    using Microsoft.Office.Interop.PowerPoint;
using System.Runtime.InteropServices;
namespace CountDown
{
    [ComVisible(true)]
    public interface IAddInUtilities
    {
        void ToggleSoundEx(Shape oShapeSymbol);
        void CountDownEx(Shape oShape);
    }
    [ComVisible(true)]
    [ClassInterface(ClassInterfaceType.None)]
    public class AddInUtilities: IAddInUtilities
    {
        public void ToggleSoundEx(Shape oShapeSymbol)
        {
            Utilities.ToggleSoundEx(oShapeSymbol);
        }
        public void CountDownEx(Shape oShape)
        {
            Utilities.CountDownEx(oShape);
        }
    }
}
  14. Add last piece of COM interface code snippet into ThisAddin class: 
    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;

namespace CountDown
{
    public partial class ThisAddIn
    {
        private AddInUtilities utilities;
        protected override object RequestComAddInAutomationService()
        {
            if (utilities == null)
                utilities = new AddInUtilities();

            return utilities;
        }

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

        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
    }
}

Points of Interest

VSTO Add-in is quite different from the VBA Add-in, besides the knowledge from Part 1, below are some additional learnings in Part 2.

  1. VBA in PPT to call function in VSTO Addin:

    "CountDown" is a sub inserted in the PPT, and "CountDownEx" is a sub defined in the VSTO Add-in.

    "ToggleSound" is a sub inserted in the PPT, and "ToggleSoundEx" is a sub defined in the VSTO Add-in.

    Public Sub ToggleSound(oShapeSymbol As Shape)
    Dim oAddIn As COMAddIn
    Dim oAddinUtility As Object
    Set oAddIn = Application.COMAddIns("CountDown")
    Set oAddinUtility = oAddIn.Object
    oAddinUtility.ToggleSoundEx oShapeSymbol
    Set oAddinUtility = Nothing
    Set oAddIn = Nothing
End Sub

Public Sub CountDown(oShape As Shape)
    Dim oAddIn As COMAddIn
    Dim oAddinUtility As Object
    Set oAddIn = Application.COMAddIns("CountDown")
    Set oAddinUtility = oAddIn.Object
    oAddinUtility.CountDownEx oShape
    Set oAddinUtility = Nothing
    Set oAddIn = Nothing
End Sub
  2. Windows API used in C#: 
            [DllImport("winmm.dll", EntryPoint = "mciSendStringA")]
        private static extern long mciSendString(string lpstrCommand, 
        string lpstrReturnString, long uReturnLength, long hwndCallback);
  3. CreateObject C# Version: 
            public static string GetBase64FromBytes(byte[] varBytes) {
            Type DomDocType = Type.GetTypeFromProgID("MSXML2.DomDocument");
            dynamic DomDocInst = Activator.CreateInstance(DomDocType);
            DomDocInst.DataType = "bin.base64";
            DomDocInst.nodeTypedValue = varBytes;
            return Strings.Replace
            (DomDocInst.Text, Constants.vbLf, Constants.vbCrLf);
        }

        public static byte[] GetBytesFromBase64(string varStr)
        {
            Type DomDocType = Type.GetTypeFromProgID("MSXML2.DomDocument");
            dynamic DomDocInst = Activator.CreateInstance(DomDocType);
            dynamic Elm = DomDocInst.createElement("b64");
            Elm.DataType = "bin.base64";
            Elm.Text = varStr;
            return Elm.nodeTypedValue;
        }
  4. Invoke function from PPT Menu (Original Functions): 
            // Show ComAddinsDialog
        private void btnComAddIns_Click(object sender, RibbonControlEventArgs e)
        {
            Globals.ThisAddIn.Application.CommandBars.ExecuteMso("ComAddInsDialog");
        }
        
        // Show VisualBasic Editor
        private void btnVisualBasic_Click(object sender, RibbonControlEventArgs e)
        {
            Globals.ThisAddIn.Application.CommandBars.ExecuteMso("VisualBasic");
        }
        
        // Show MacroSecurity Dialog
        Globals.ThisAddIn.Application.CommandBars.ExecuteMso("MacroSecurity");
  5. To use the VBA MsgBox: 
                using Microsoft.VisualBasic;
            Interaction.MsgBox (...)

History

  • 11th October, 2022: Initial version