C#/VB.NET: Replace a Picture in Excel
Sometimes after you have finished an Excel workbook, you may need to replace some of the existing pictures with better ones for the purpose of making the workbook more appealing and persuasive. In this tutorial, you will learn how to replace a picture in Excel using 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 DLLs files can be either downloaded from this link or installed via NuGet.
- Package Manager
PM> Install-Package Spire.XLS
Replace a Picture in Excel
The following are the detailed steps to replace a picture with another one using Spire.XLS for .NET.
- Create a Workbook object.
- Load a sample file using Workbook.LoadFromFile() method.
- Use Workbook.Worksheets[0] to get the first worksheet.
- Use Worksheet.Pictures[0] property to get the first picture from the first worksheet
- Use Image.FromFile() method to load an image from the specified file, and set it as a new value of ExcelPicture.Picture property. To do so, the original picture will be replaced with the new one.
- Save the document using Workbook.SaveToFile() method.
- C#
- VB.NET
using Spire.Xls;
using Spire.Xls.Collections;
namespace ReplacePictureinExcel
{
class Program
{
static void Main(string[] args)
{
//Create a Workbook instance
Workbook workbook = new Workbook();
//Load the Excel file
workbook.LoadFromFile("input.xls");
//Get the first sheet
Worksheet sheet = workbook.Worksheets[0];
//Get Excel picture collection
PicturesCollection pictureCollection = sheet.Pictures;
//Get the first picture from the collection
ExcelPicture excelPicture = pictureCollection[0];
// Creates an Image from the specified file.
excelPicture.Picture = System.Drawing.Image.FromFile("input.png");
//Save the document
workbook.SaveToFile("ReplaceImage.xlsx", ExcelVersion.Version2013);
}
}
}
Imports Spire.Xls
Imports Spire.Xls.Collections
Imports System.Drawing
Namespace ReplacePictureinExcel
Class Program
Private Shared Sub Main(args As String())
'Create a Workbook instance
Dim workbook As New Workbook()
'Load the Excel file
workbook.LoadFromFile(Input.xls)
'Get the first sheet
Dim sheet As Worksheet = workbook.Worksheets(0)
'Get Excel picture collection
Dim pictureCollection As PicturesCollection = sheet.Pictures
'Get the first picture from the collection
Dim excelPicture As ExcelPicture = pictureCollection(0)
' Creates an Image from the specified file.
excelPicture.Picture = Image.FromFile(image)
'Save the document
workbook.SaveToFile("ReplaceImage.xlsx", ExcelVersion.Version2013)
End Sub
End Class
End Namespace
The original file:

The generated file:

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.
Java: Add Data Bars in Excel
Data bars are a type of conditional formatting Microsoft Excel offers for visualizing the values in Excel cells. They can help you compare the values quickly because a cell with a longer bar represents a larger value, while a cell with a shorter bar represents a smaller value. This article will introduce how to add data bars in a range of cells using Spire.XLS for Java.
Install Spire.XLS for Java
First of all, you're required to add the Spire.Xls.jar file as a dependency in your Java program. The JAR file can be downloaded from this link. If you use Maven, you can easily import the JAR file in your application by adding the following code to your project's pom.xml file.
<repositories>
<repository>
<id>com.e-iceblue</id>
<name>e-iceblue</name>
<url>https://repo.e-iceblue.com/nexus/content/groups/public/</url>
</repository>
</repositories>
<dependencies>
<dependency>
<groupId>e-iceblue</groupId>
<artifactId>spire.xls</artifactId>
<version>16.4.1</version>
</dependency>
</dependencies>
Add Data Bars in Excel
The following are steps to add data bars in a range of Excel cells through conditional formatting:
- Create a Workbook instance.
- Load an Excel file using Workbook.loadFromFile() method.
- Get the worksheets collection using Workbook.getWorksheets() method, and then get the first worksheet using WorksheetsCollection.get() method.
- Get a specific cell range using Worksheet.getCellRange() method.
- Add a new conditional formatting to the cell range using ConditionalFormats. addCondition(), and then set the type of the new conditional formatting to DataBar using ConditionalFormatWrapper.setFormatType() method.
- Set the color of the data bar using DataBar.setBarColor() method.
- Save the document to another file using Workbook.saveToFile() method.
- Java
import com.spire.xls.*;
import com.spire.xls.core.IConditionalFormat;
import com.spire.xls.core.spreadsheet.collections.XlsConditionalFormats;
import java.awt.*;
public class applyDataBars {
public static void main(String[] args) {
//Create a Workbook instance
Workbook workbook = new Workbook();
//Load an Excel file
workbook.loadFromFile("C:\\Users\\Administrator\\Desktop\\test.xlsx");
//Get the first worksheet.
Worksheet sheet = workbook.getWorksheets().get(0);
//Add a conditional formatting and specify ranges
XlsConditionalFormats conditional = sheet.getConditionalFormats().add();
conditional.addRange(sheet.getCellRange("B2:B13"));
//Add the conditional formatting of data bars
IConditionalFormat format = conditional.addCondition();
format.setFormatType( ConditionalFormatType.DataBar);
//Set color for the data bars
format.getDataBar().setBarColor( Color.GREEN);
//Save to file
workbook.saveToFile("ApplyDataBars.xlsx", ExcelVersion.Version2013);
}
}

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.
Add Multiline Watermarks to PowerPoint in Java
This article demonstrates how to add multiline watermarks to a PowerPoint slide using Spire.Presentation for Java. To add watermarks to all slides, use one more for loop outside the two for loops in the following code snippet.
import com.spire.presentation.*;
import com.spire.presentation.Presentation;
import com.spire.presentation.drawing.*;
import java.awt.*;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
//Create a Presentation object
Presentation presentation = new Presentation();
//Load the sample PowerPoint file
presentation.loadFromFile("C:\\Users\\Administrator\\Desktop\\Spire.Presentation.pptx");
//Specify watermark text
String watermarkText = "E-iceblue";
//Get the size of the watermark text
Image image = new BufferedImage(1, 1, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = (Graphics2D) image.getGraphics();
Font font = new Font("Arial", Font.BOLD, 20);
g2d.setFont(font);
FontMetrics fm = g2d.getFontMetrics();
Rectangle2D strSize = fm.getStringBounds(watermarkText, g2d);
//Initialize x and y coordinate
float x = 30;
float y = 80;
for (int rowNum = 0; rowNum < 4; rowNum++) {
for (int colNum = 0; colNum < 5; colNum++) {
//Add a rectangle shape
Rectangle2D rect = new Rectangle2D.Float(x, y, (float) strSize.getWidth() + 10, (float) strSize.getHeight());
IAutoShape shape = presentation.getSlides().get(0).getShapes().appendShape(ShapeType.RECTANGLE, rect);
//Set the style of the shape
shape.getFill().setFillType(FillFormatType.NONE);
shape.getShapeStyle().getLineColor().setColor(new Color(1, 1, 1, 0));
shape.setRotation(-45);
shape.getLocking().setSelectionProtection(true);
shape.getLine().setFillType(FillFormatType.NONE);
//Add watermark text to the shape
shape.getTextFrame().setText(watermarkText);
PortionEx textRange = shape.getTextFrame().getTextRange();
//Set the style of the text range
textRange.getFill().setFillType(FillFormatType.SOLID);
textRange.getFill().getSolidColor().setColor(Color.pink);
textRange.setLatinFont(new TextFont(font.getName()));
textRange.setFontMinSize(font.getSize());
x += (100 + strSize.getWidth());
}
x = 30;
y += (100 + strSize.getHeight());
}
//Save the document
presentation.saveToFile("output/Watermark.pptx", FileFormat.PPTX_2013);

Convert Shapes and SmartArt in Excel to Image in C#, VB.NET
This article demonstrates how to convert shapes and SmartArt graphics in Excel to Image in C# using Spire.XLS for .NET.
The input Excel file:

using Spire.Xls;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;
namespace Convert_Shapes_and_SmartArt_to_Image
{
class Program
{
static void Main(string[] args)
{
//Create a Workbook object
Workbook workbook = new Workbook();
//Load the Excel file
workbook.LoadFromFile("Sample.xlsx");
//Get the first worksheet
Worksheet sheet = workbook.Worksheets[0];
//Create a SaveShapeTypeOption object
SaveShapeTypeOption shapelist = new SaveShapeTypeOption();
//Save shapes and SmartArt graphics in the worksheet to images
List<Bitmap> images = sheet.SaveShapesToImage(shapelist);
//Save images to file
int index = 0;
foreach (Image img in images)
{
img.Save("Image/" + "toImage" + index + ".Png", ImageFormat.Png);
index++;
}
}
}
}
Imports Spire.Xls
Imports System.Collections.Generic
Imports System.Drawing.Imaging
Namespace Convert_Shapes_and_SmartArt_to_Image
Friend Class Program
Private Shared Sub Main(ByVal args As String())
'Create a Workbook object
Dim workbook As Workbook = New Workbook()
'Load the Excel file
workbook.LoadFromFile("Sample.xlsx")
'Get the first worksheet
Dim sheet As Worksheet = workbook.Worksheets(0)
'Create a SaveShapeTypeOption object
Dim shapelist As SaveShapeTypeOption = New SaveShapeTypeOption()
'Save shapes and SmartArt graphics in the worksheet to images
Dim images As List(Of Bitmap) = sheet.SaveShapesToImage(shapelist)
'Save images to file
Dim index As Integer = 0
For Each img As Image In images
img.Save("Image/" & "toImage" & index & ".Png", ImageFormat.Png)
index += 1
Next
End Sub
End Class
End Namespace
Converted images:

Verify If a Word Document is Password Protected in Java
This article demonstrates how to verify if a Word document is password protected or not using Spire.Doc for Java.
The following image shows that the input Word document is protected with password:

import com.spire.doc.Document;
public class DetectIfWordIsPasswordProtected {
public static void main(String []args){
//Detect if the Word document is password protected
boolean isPasswordProtected = Document.isEncrypted("C:\\Users\\Administrator\\Desktop\\Sample.docx");
if(isPasswordProtected)
{
System.out.println("The document is password protected.");
}
else
{
System.out.println("The document is not password protected.");
}
}
}
Output:

Compress High-resolution Images in PDF in Java
This article demonstrates how to compress high-resolution images of a PDF document using Spire.PDF for Java. Images in low-resolution will not be compressed anymore.
public static void main(String[] args) throws Exception {
//Load the sample PDF document
PdfDocument doc = new PdfDocument("C:\\Users\\Administrator\\Desktop\\Images.pdf");
//Set IncrementalUpdate to false
doc.getFileInfo().setIncrementalUpdate(false);
//Declare a PdfPageBase variable
PdfPageBase page;
// Create the PdfImageHelper object
PdfImageHelper imageHelper = new PdfImageHelper();
//Loop through the pages
for (int i = 0; i < doc.getPages().getCount(); i++) {
//Get the specific page
page = doc.getPages().get(i);
if (page != null) {
if(page.getImagesInfo() != null){
//Loop through the images in the page
for (PdfImageInfo info : imageHelper.getImagesInfo(page))
//Use tryCompressImage method the compress high-resolution images
info.tryCompressImage();
}
}
}
//Save to file
doc.saveToFile("output/Compressed.pdf");
}

Extract Files from PDF Portfolio in Java
This article demonstrates how to extract files from a PDF portfolio in Java using Spire.PDF for Java.
The input PDF:

import com.spire.pdf.PdfDocument;
import com.spire.pdf.attachments.PdfAttachment;
import java.io.*;
public class ReadPortfolio {
public static void main(String []args) throws IOException {
//Create a PdfDocument instance
PdfDocument pdf = new PdfDocument();
//Load the PDF file
pdf.loadFromFile("Portfolio.pdf");
//Loop through the attachments in the file
for(Object obj : pdf.getAttachments()) {
PdfAttachment attachment = (PdfAttachment) obj;
//Extract files
String fileName = attachment.getFileName();
OutputStream fos = new FileOutputStream("extract/" + fileName);
fos.write(attachment.getData());
}
pdf.dispose();
}
}
Output:

C#/VB.NET: Add or Remove Digital Signatures in PowerPoint
A digital signature is a modern alternative to signing documents manually on paper with pen. It uses an advanced mathematical technique to check the authenticity and integrity of digital documents, which guarantees that the contents in a digital document comes from the signer and has not been altered since then. Sometimes PowerPoint documents that contain confidential information may require a signature. In this article, you will learn how to programmatically add or remove digital signatures in PowerPoint using Spire.Presentation for .NET.
- Add a Digital Signature to PowerPoint in C# and VB.NET
- Remove All Digital Signatures from PowerPoint in C# and VB.NET
Install Spire.Presentation for .NET
To begin with, you need to add the DLL files included in the Spire.Presentation 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.Presentation
Add a Digital Signature to PowerPoint in C# and VB.NET
To add a digital signature, you'll need to have a valid signature certificate first. Then you can digitally sign a PowerPoint document with the certificate using Presentation.AddDigitalSignature (X509Certificate2 certificate, string comments, DateTime signTime) method. The detailed steps are as follows.
- Create a Presentation instance.
- Load a sample PowerPoint document using Presentation.LoadFromFile() method.
- Initializes an instance of X509Certificate2 class with the certificate file name and password.
- Add a digital signature to the PowerPoint document using Presentation.AddDigitalSignature (X509Certificate2 certificate, string comments, DateTime signTime) method.
- Save result document using Presentation.SaveToFile() method.
- C#
- VB.NET
using Spire.Presentation;
using System;
namespace AddDigitalSignature
{
class Program
{
static void Main(string[] args)
{
//Create a Presentation instance
Presentation ppt = new Presentation();
//Load a PowerPoint document
ppt.LoadFromFile("Input.pptx");
//Add a digital signature
ppt.AddDigitalSignature("gary.pfx", "e-iceblue", "test", DateTime.Now);
//Save the result document
ppt.SaveToFile("AddDigitalSignature_result.pptx", FileFormat.Pptx2010);
System.Diagnostics.Process.Start("AddDigitalSignature_result.pptx");
//Dispose
ppt.Dispose();
}
}
}

Remove All Digital Signatures from PowerPoint in C# and VB.NET
At some point you may need to remove the digital signatures from a PowerPoint document. Spire.Presentation for .NET provides the Presentation.RemoveAllDigitalSignatures() method to remove all digital signatures at once. The detailed steps are as follows:
- Create a Presentation instance.
- Load a sample PowerPoint document using Presentation.LoadFromFile() method.
- Determine if the document contains digital signatures using Presentation.IsDigitallySigned property.
- Remove all digital signatures from the document using Presentation.RemoveAllDigitalSignatures() method.
- Save the result document using Presentation.SaveToFile() method.
- C#
- VB.NET
using Spire.Presentation;
namespace RemoveDigitalSignature
{
class Program
{
static void Main(string[] args)
{
//Create a Presentation instance
Presentation ppt = new Presentation();
//Load a PowerPoint document
ppt.LoadFromFile("AddDigitalSignature.pptx");
//Detect if the document is digitally signed
if (ppt.IsDigitallySigned == true)
{
//Remove all digital signatures
ppt.RemoveAllDigitalSignatures();
}
//Save the result document
ppt.SaveToFile("RemoveDigitalSignature.pptx", FileFormat.Pptx2013);
}
}
}

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.
Download PDF Document from URL in C#/VB.NET
This article shows you how to download a PDF document from an URL using Spire.PDF with C# and VB.NET.
using System.IO;
using System.Net;
using Spire.Pdf;
namespace DownloadPdfFromUrl
{
class Program
{
static void Main(string[] args)
{
//Create a PdfDocument object
PdfDocument doc = new PdfDocument();
//Create a WebClient object
WebClient webClient = new WebClient();
//Download data from URL and save as memory stream
using (MemoryStream ms = new MemoryStream(webClient.DownloadData("https://www.e-iceblue.com/article/toDownload.pdf")))
{
//Load the stream
doc.LoadFromStream(ms);
}
//Save to PDF file
doc.SaveToFile("result.pdf", FileFormat.PDF);
}
}
}
Imports System.IO
Imports System.Net
Imports Spire.Pdf
Namespace DownloadPdfFromUrl
Class Program
Shared Sub Main(ByVal args() As String)
'Create a PdfDocument object
Dim doc As PdfDocument = New PdfDocument()
'Create a WebClient object
Dim webClient As WebClient = New WebClient()
'Download data from URL and save as memory stream
Dim pdfData As Byte() = webClient.DownloadData(""https://www.e-iceblue.com/article/toDownload.pdf"")
Using ms As New MemoryStream(pdfData)
'Load the stream
doc.LoadFromStream(ms)
End Using
'Save to PDF file
doc.SaveToFile(""result.pdf"", FileFormat.PDF)
End Sub
End Class
End Namespace

Java remove the formulas but keep the values on Excel worksheet
This article will demonstrate how to use Spire.XLS for Java to remove the formulas but keep the values on the Excel worksheet.
Firstly, view the original Excel:

String inputFile = "Sample.xlsx";
String outputFile="output/removeFormulasButKeepValues_result.xlsx";
//Create a workbook.
Workbook workbook = new Workbook();
//Load the file from disk.
workbook.loadFromFile(inputFile);
//Loop through worksheets.
for (Worksheet sheet : (Iterable<? extends Worksheet>) workbook.getWorksheets())
{
//Loop through cells.
for (CellRange cell : (Iterable<? extends CellRange>) sheet.getRange())
{
//If the cell contains formula, get the formula value, clear cell content, and then fill the formula value into the cell.
if (cell.hasFormula())
{
Object value = cell.getFormulaValue();
cell.clear(ExcelClearOptions.ClearContent);
cell.setValue(value.toString());
}
}
}
//Save to file
workbook.saveToFile(outputFile, ExcelVersion.Version2013);
Output:
