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Converting HTML to images enables the transformation of dynamic web content-such as text, graphics, and layouts-into static formats like PNG or JPEG. This process is ideal for capturing web pages for documentation, generating thumbnails, or ensuring visually consistent content across platforms, providing both accuracy and versatility.
In this article, you'll learn how to convert HTML files and strings to images using C# with Spire.Doc for .NET.
Install Spire.Doc for .NET
To begin with, you need to add the DLL files included in the Spire.Doc for .NET package as references in your .NET project. The DLL files can be either downloaded from this link or installed via NuGet.
PM> Install-Package Spire.Doc
Convert an HTML File to Image in C#
Using Spire.Doc for .NET, you can directly load an HTML file by utilizing the Document.LoadFromFile() method. Once loaded, you can convert the document into Bitmap images with the Document.SaveToImages() method. Afterward, you can loop through the generated images and save each one in widely-used image formats such as PNG, JPG, or BMP.
The following are the steps to convert an HTML file to images using Spire.Doc in C#:
- Create a Document object.
- Load an HTML file using the Document.LoadFromFile() method.
- Adjust properties such as margins, which will affect the output image's layout.
- Call the Document.SaveToImages() method to convert the loaded document into an array of Bitmap images.
- Iterate through the images and save each one to your desired output format.
- C#
using Spire.Doc;
using Spire.Doc.Documents;
using System.Drawing;
using System.Drawing.Imaging;
namespace ConvertHtmlFileToPng
{
class Program
{
static void Main(string[] args)
{
// Create a Document object
Document document = new Document();
// Load an HTML file
document.LoadFromFile(@"C:\Users\Administrator\Desktop\MyHtml.html", FileFormat.Html, XHTMLValidationType.None);
// Get the first section
Section section = document.Sections[0];
// Set the page margins
section.PageSetup.Margins.All = 2;
// Convert the document to an array of bitmap images
Image[] images = document.SaveToImages(ImageType.Bitmap);
// Iterate through the images
for (int index = 0; index < images.Length; index++)
{
// Specify the output file name
string fileName = string.Format(@"C:\Users\Administrator\Desktop\Output\image_{0}.png", index);
// Save each image as a PNG file
images[index].Save(fileName, ImageFormat.Png);
}
// Dispose resources
document.Dispose();
}
}
}
Convert an HTML String to Image in C#
In certain scenarios, you might need to convert an HTML string directly into an image. This approach is especially beneficial for handling dynamically generated content or when you prefer not to depend on external HTML files.
Here is how you can convert an HTML string to images using Spire.Doc in C#:
- Create a Document object.
- Add a section and a paragraph to the document.
- Adjust properties such as margins, which will affect the output image's layout.
- Read the HTML string from a file or define it directly in the script.
- Use the Paragraph.AppendHTML() method to render the HTML content in the document.
- Call the Document.SaveToImages() method to convert the document into an array of Bitmap images.
- Iterate through the images and save each one to your desired output format.
- C#
using Spire.Doc;
using Spire.Doc.Documents;
using System.Drawing;
using System.Drawing.Imaging;
namespace ConvertHtmlStringToPng
{
class Program
{
static void Main(string[] args)
{
// Create a Document object
Document document = new Document();
// Add a section to the document
Section section = document.AddSection();
// Set the page margins
section.PageSetup.Margins.All = 2;
// Add a paragraph to the section
Paragraph paragraph = section.AddParagraph();
// Read HTML string from a file
string htmlFilePath = @"C:\Users\Administrator\Desktop\Html.html";
string htmlString = File.ReadAllText(htmlFilePath, System.Text.Encoding.UTF8);
// Append the HTML string to the paragraph
paragraph.AppendHTML(htmlString);
// Convert the document to an array of bitmap images
Image[] images = document.SaveToImages(ImageType.Bitmap);
// Iterate through the images
for (int index = 0; index < images.Length; index++)
{
// Specify the output file name
string fileName = string.Format(@"C:\Users\Administrator\Desktop\Output\image_{0}.png", index);
// Save each image as a PNG file
images[index].Save(fileName, ImageFormat.Png);
}
// Dispose resources
document.Dispose();
}
}
}
Apply for a Temporary License
If you'd like to remove the evaluation message from the generated documents, or to get rid of the function limitations, please request a 30-day trial license for yourself.
Excel's Find and Replace feature is an indispensable tool for users when editing large Excel spreadsheets. It allows users to search for specific values within a worksheet or cell range and update them with new values quickly and accurately. With this feature, users don't need to perform manual searches, which significantly improves their working efficiency. In this article, we will introduce how to programmatically find and replace data in Excel in C# and VB.NET using Spire.XLS for .NET library.
- Find and Replace Data in a Worksheet in Excel
- Find and Replace Data in a Specific Cell Range in Excel
Install Spire.XLS for .NET
To begin with, you need to add the DLL files included in the Spire.XLS for .NET package as references in your .NET project. The DLL files can be either downloaded from this link or installed via NuGet.
PM> Install-Package Spire.XLS
Find and Replace Data in a Worksheet in Excel in C# and VB.NET
Spire.XLS for .NET offers the Worksheet.FindAllString(string stringValue, bool formula, bool formulaValue) method which enables you to find the cells containing specific data values in an Excel worksheet. Once the cells are found, you can use the CellRange.Text property to update their values with new values. The detailed steps are as follows:
- Initialize an instance of the Workbook class.
- Load an Excel file using the Workbook.LoadFromFile(string fileName) method.
- Get a specific worksheet of the file using the Workbook.Worksheets[int index] property.
- Find the cells containing a specific value in the worksheet using the Worksheet.FindAllString(string stringValue, bool formula, bool formulaValue) method.
- Iterate through the found cells.
- Update the value of each cell with another value using the CellRange.Text property.
- Set a background for the cell so you can easily find the updated cells using the CellRange.Style.Color property.
- Save the result file to a specific location using the Workbook.SaveToFile(string fileName, ExcelVersion version) method.
- C#
- VB.NET
using Spire.Xls;
using System.Drawing;
namespace ReplaceDataInWorksheet
{
internal class Program
{
static void Main(string[] args)
{
//Initialize an instance of the Workbook class
Workbook workbook = new Workbook();
//Load an Excel file
workbook.LoadFromFile(@"Sample.xlsx");
//Get the first worksheet
Worksheet worksheet = workbook.Worksheets[0];
//Find the cells with the specific string value “Total” in the worksheet
CellRange[] cells = worksheet.FindAllString("Total", true, true);
//Iterate through the found cells
foreach (CellRange cell in cells)
{
//Replace the value of the cell with another value
cell.Text = "Sum";
//Set a background color for the cell
cell.Style.Color = Color.Yellow;
}
//Save the result file to a specific location
workbook.SaveToFile("ReplaceDataInWorksheet.xlsx", ExcelVersion.Version2016);
workbook.Dispose();
}
}
}
Find and Replace Data in a Specific Cell Range in Excel in C# and VB.NET
You can find the cells containing a specific value in a cell range using the CellRange.FindAllString(string stringValue, bool formula, bool formulaValue) method. Then you can update the value of each found cell with another value using the CellRange.Text property. The detailed steps are as follows:
- Initialize an instance of the Workbook class.
- Load an Excel file using the Workbook.LoadFromFile(string fileName) method.
- Get a specific worksheet of the file using the Workbook.Worksheets[int index] property.
- Get a specific cell range of the worksheet using the Worksheet.Range[string rangeName] property.
- Find the cells with a specific value in the cell range using the CellRange.FindAllString(string stringValue, bool formula, bool formulaValue) method.
- Iterate through the found cells.
- Update the value of each found cell to another value using the CellRange.Text property.
- Set a background for the cell so you can easily find the updated cells using the CellRange.Style.Color property.
- Save the result file to a specific location using the Workbook.SaveToFile(string fileName, ExcelVersion version) method.
- C#
- VB.NET
using Spire.Xls;
using System.Drawing;
namespace ReplaceDataInCellRange
{
internal class Program
{
static void Main(string[] args)
{
//Initialize an instance of the Workbook class
Workbook workbook = new Workbook();
//Load an Excel file
workbook.LoadFromFile(@"Sample.xlsx");
//Get the first worksheet
Worksheet worksheet = workbook.Worksheets[0];
//Get a specific cell range
CellRange range = worksheet.Range["A1:C9"];
//Find the cells with the specific value "Total" in the cell range
CellRange[] cells = range.FindAllString("Total", true, true);
//Iterate through the found cells
foreach (CellRange cell in cells)
{
//Replace the value of the cell with another value
cell.Text = "Sum";
//Set a background color for the cell
cell.Style.Color = Color.Yellow;
}
//Save the result file to a specific location
workbook.SaveToFile("ReplaceDataInCellRange.xlsx", ExcelVersion.Version2016);
workbook.Dispose();
}
}
}
Apply for a Temporary License
If you'd like to remove the evaluation message from the generated documents, or to get rid of the function limitations, please request a 30-day trial license for yourself.
Textboxes in Excel are versatile tools that allow users to add annotations, labels, or any additional information to their spreadsheets. Whether you want to highlight important data, provide explanations, or create visually appealing reports, managing textboxes is essential.
In this article, you will learn how to add a textbox, extract content from an existing textbox, and remove a textbox in Excel using C# and Spire.XLS for .NET.
Install Spire.XLS for .NET
To begin with, you need to add the DLL files included in the Spire.XLS for .NET package as references in your .NET project. The DLL files can be either downloaded from this link or installed via NuGet.
PM> Install-Package Spire.XLS
Add a Textbox to Excel in C#
A textbox can be added to a worksheet using the Worksheet.TextBoxes.AddTextBox() method. This method returns an ITextBoxShape object, which contains properties such as Text, HAlignment, and Fill, for configuring the text and formatting of the textbox.
The steps to add a textbox with customized text and formatting to Excel are as follows:
- Create a Workbook object.
- Load an Excel file from the specified file path.
- Get a specific worksheet from the workbook.
- Add a textbox to the worksheet at the specified location using Worksheet.TextBoxes.AddTextBox() method.
- Set the text of the textbox using ITextBoxShape.Text property.
- Customize the appearance of the textbox using other properties of the ITextBoxShape object.
- Save the workbook to a different Excel file.
- C#
using Spire.Xls;
using Spire.Xls.Core;
using System.Drawing;
namespace AddTextbox
{
class Program
{
static void Main(string[] args)
{
// Create a Workbook object
Workbook workbook = new Workbook();
// Load an Excel document
workbook.LoadFromFile("C:\\Users\\Administrator\\Desktop\\Input.xlsx");
// Get a specific sheet
Worksheet sheet = workbook.Worksheets[0];
// Add a textbox to the specified location
ITextBoxShape textBoxShape = sheet.TextBoxes.AddTextBox(3, 3, 60, 200);
// Set text of the textbox
textBoxShape.Text = "This is a text box, with sample text.";
// Create a font
ExcelFont font = workbook.CreateFont();
font.FontName = "Calibri";
font.Size = 14;
font.Color = Color.Red;
// Apply font to the text
textBoxShape.RichText.SetFont(0, textBoxShape.Text.Length - 1, font);
// Set horizontal alignment
textBoxShape.HAlignment = CommentHAlignType.Left;
// Set the fill color of the shape
textBoxShape.Fill.FillType = ShapeFillType.SolidColor;
textBoxShape.Fill.ForeColor = Color.LightGreen;
// Save the Excel file
workbook.SaveToFile("output/AddTextBox.xlsx", ExcelVersion.Version2010);
// Dispose resources
workbook.Dispose();
}
}
}
Extract Text from a Textbox in Excel in C#
A specific textbox can be accessed using the Worksheet.TextBoxes[index] property. Once retrieved, the textbox's text can be accessed through the ITextBox.Text property.
The steps to extract text from a textbox in Excel are as follows:
- Create a Workbook object.
- Load an Excel file from the specified file path.
- Get a specific worksheet from the workbook.
- Get the text of a specific textbox using Worksheet.TextBoxes[index] property.
- Get the text of the textbox using ITextBox.Text property.
- C#
using Spire.Xls;
using Spire.Xls.Core;
namespace ExtractTextFromTextbox
{
class Program
{
static void Main(string[] args)
{
// Create a Workbook object
Workbook workbook = new Workbook();
// Load an Excel file
workbook.LoadFromFile("C:\\Users\\Administrator\\Desktop\\TextBox.xlsx");
// Get a specific worksheet
Worksheet sheet = workbook.Worksheets[0];
// Get a specific textbox
ITextBox textBox = sheet.TextBoxes[0];
// Get text from the textbox
String text = textBox.Text;
// Print out result
Console.WriteLine(text);
}
}
}
Remove a Textbox from Excel in C#
To remove a specific textbox from a worksheet, use the Worksheet.TextBoxes[index].Remove() method. To clear all textboxes, retrieve the count with the Worksheet.TextBoxes.Count property and iterate through the collection, removing each textbox individually.
The steps to remove a textbox from Excel are as follows:
- Create a Workbook object.
- Load an Excel file from the specified file path.
- Get a specific worksheet from the workbook.
- Remove a specific textbox using Worksheet.TextBoxes[index].Remove() method.
- Save the workbook to a different Excel file.
- C#
using Spire.Xls;
namespace RemoveTextbox
{
class Program
{
static void Main(string[] args)
{
// Create a Workbook object
Workbook workbook = new Workbook();
// Load an Excel file
workbook.LoadFromFile("C:\\Users\\Administrator\\Desktop\\TextBox.xlsx");
// Get a specific worksheet
Worksheet sheet = workbook.Worksheets[0];
// Remove a specific textbox
sheet.TextBoxes[0].Remove();
// Save the updated document to a different Excel file
workbook.SaveToFile("output/RemoveTextbox.xlsx", ExcelVersion.Version2016);
// Dispose resources
workbook.Dispose();
}
}
}
Apply for a Temporary License
If you'd like to remove the evaluation message from the generated documents, or to get rid of the function limitations, please request a 30-day trial license for yourself.
