How to Convert HTML table to PowerPoint by Free API

Introduction

This article will explain in detail to convert HTML to Word, Excel and PowerPoint. It is easy to find the solution for the first two conversions on free resources site. But the solution for converting HTML to PowerPoint seems to be lack, while spending a lot of time and effort is still pretty lucky to find a solution for converting HTML table to PowerPoint. Hope this article helps other developers. In this solution, two free apis(Html Agility Pack and Spire.Presentation) are used, below will introduce it in detail.

Application Overview

public DataTable ConvertHTMLTableToDataTable(string htmlfile)
{
//Create an HTMLDocument
var doc = new HtmlAgilityPack.HtmlDocument();
//Load an html file
doc.Load(htmlfile);
//Get the nodes of tags<table>
var nodes = doc.DocumentNode.SelectNodes("//table/tr");
//Create an DataTable and named it as MyTable
var table = new DataTable("MyTable");
//Get the nodes of the tags<th>
var headers = nodes[0].Elements("th").Select(th => th.InnerText.Trim());
//Add columns for dataTable
foreach (var header in headers)
{
table.Columns.Add(header);
}
//Get the nodes of the tags<td>
var rows = nodes.Skip(1).Select(tr => tr.Elements("td").Select(td => td.InnerText.Trim()).ToArray());
//Add rows for dataTable
foreach (var row in rows)
{
table.Rows.Add(row);
}
return table;
}

Next, load a html file to call ConvertHTMLtoDataTable method to get its dataTable.

DataTable dt = ConvertHTMLtoDataTable("C:\\test.html");

The screenshot for DataTable:

The second stage, Spire.Presentation is used to create a PPTX document with the data in above dataTable, detailed as follows.

//Create a PowerPoint document
Presentation presentation = new Presentation();
//Define column width
Double[] widths = new double[] { 100,80, 80, 80, 80 };
//Define row height
Double[] heights = new double[] { 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15 };
//Add new table to PPT
ITable table = presentation.Slides[0].Shapes.AppendTable(presentation.SlideSize.Size.Width
/ 2 - 220, 80, widths, heights);
//Add header of table
for (int j = 0; j < dt.Columns.Count; j++)
{
table[j, 0].TextFrame.Text = dt.Columns[j].ToString();
}
//Fill the table with data in dataTable
for (int i = 1; i <= dt.Rows.Count; i++)
{
for (int j = 0; j < dt.Columns.Count; j++)
{
table[j, i].TextFrame.Text = dt.Rows[i - 1][j].ToString();
//set the Font
table[j,i].TextFrame.Paragraphs[0].TextRanges[0].LatinFont = new TextFont("Arial Narrow");
}
}
//set the style of table
table.StylePreset = TableStylePreset.None;
//save thedocument
presentation.SaveToFile("table.pptx", FileFormat.Pptx2010);

The screenshot for PPTX document: