如何在 C# 中向 Word 文件添加水印

IronWord

IronWord is a reliable and easy-to-use C# Docx library that allows developers to build and edit Word documents using C# without relying on traditional dependencies such as Microsoft Office or Word Interop.

Furthermore, it has extensive documentation and fully supports .NET 8, 7, 6, Framework, Core, and Azure. This makes it cross-platform compatible with most applications and flexible no matter the application you are dealing with.

License Key

Please remember that IronWord requires a licensing key for operation. You can get a key as part of a free trial by visiting this link.

// Replace the license key variable with the trial key you obtained
IronWord.License.LicenseKey = "REPLACE-WITH-YOUR-KEY";

// Replace the license key variable with the trial key you obtained
IronWord.License.LicenseKey = "REPLACE-WITH-YOUR-KEY";

' Replace the license key variable with the trial key you obtained
IronWord.License.LicenseKey = "REPLACE-WITH-YOUR-KEY"

After receiving a trial key, set this variable in your project.

Add Image Watermark to Word Document

Let's examine an example of adding an image watermark to a Word Document. We won't mention static void main to reduce repetitive code but will showcase only the main code.

We will use this image as the watermark image and add it to the Word document.

using IronWord;
using IronWord.Models;
using IronWord.Models.Enums;

// Set the license key
IronWord.License.LicenseKey = "YOUR-KEY";

// Create a new Word document
WordDocument doc = new WordDocument();

// Load the image to be used as a watermark
IronWord.Models.Image image = new IronWord.Models.Image("ironword.png");

// Set the width and height of the image
image.Width = 500; // In pixels
image.Height = 250; // In pixels

// Add the image as a watermark to the document
doc.AddImage(image);

// Save the document as a .docx file
doc.SaveAs("documentImageResized.docx");

using IronWord;
using IronWord.Models;
using IronWord.Models.Enums;

// Set the license key
IronWord.License.LicenseKey = "YOUR-KEY";

// Create a new Word document
WordDocument doc = new WordDocument();

// Load the image to be used as a watermark
IronWord.Models.Image image = new IronWord.Models.Image("ironword.png");

// Set the width and height of the image
image.Width = 500; // In pixels
image.Height = 250; // In pixels

// Add the image as a watermark to the document
doc.AddImage(image);

// Save the document as a .docx file
doc.SaveAs("documentImageResized.docx");

Imports IronWord
Imports IronWord.Models
Imports IronWord.Models.Enums

' Set the license key
IronWord.License.LicenseKey = "YOUR-KEY"

' Create a new Word document
Dim doc As New WordDocument()

' Load the image to be used as a watermark
Dim image As New IronWord.Models.Image("ironword.png")

' Set the width and height of the image
image.Width = 500 ' In pixels
image.Height = 250 ' In pixels

' Add the image as a watermark to the document
doc.AddImage(image)

' Save the document as a .docx file
doc.SaveAs("documentImageResized.docx")

1. We first create a new instance of the WordDocument. This is the document class from IronWord. In the next steps, we create a new variable called doc and add the picture watermark to it.
2. We load our input image from above into a new Image class.
3. We set the width and height of the image accordingly. This width and height property allows users to accomplish image watermark scaling. In our example, the width is set to 500, and the height is set to 250.
4. We add the image watermark to the document using AddImage.
5. Finally, we save and export the document documentImageResized as a Word file.

The output of the Word document is below.

Keep in mind that the dimensions set in the example are made to fit the whole Word document and display IronWord's capabilities.

In addition to adding the image, we can use the WrapText property to ensure that the image watermark stays behind the text in the background.

// Set the image to wrap behind the text
image.WrapText = WrapText.BehindText;

// Set the image to wrap behind the text
image.WrapText = WrapText.BehindText;

' Set the image to wrap behind the text
image.WrapText = WrapText.BehindText

Through this property, the image watermark should wrap behind the text, only showing in the background, allowing the text to be unhindered.

Furthermore, developers can try more customizations for the image watermark to make it unique. IronWord allows you to offset the dimensions of the image relative to the Word document and manage the position of the image watermark as well.

using IronWord;
using IronWord.Models;

// Set the license key
IronWord.License.LicenseKey = "YOUR-KEY";

// Create a new Word document
WordDocument doc = new WordDocument();

// Load the image to be used as a watermark
IronWord.Models.Image image = new IronWord.Models.Image("ironword.png");

// Create an ElementPosition object to set the position
ElementPosition elementPosition = new ElementPosition();
elementPosition.SetXPosition(50);
elementPosition.SetYPosition(50);

// Set the dimensions of the image
image.Width = 50; // In pixels
image.Height = 50; // In pixels

// Set the image position using the ElementPosition object
image.Position = elementPosition;

// Offset the image from each side by 100 pixels
image.DistanceFromTop = 100;
image.DistanceFromBottom = 100;
image.DistanceFromLeft = 100;
image.DistanceFromRight = 100;

using IronWord;
using IronWord.Models;

// Set the license key
IronWord.License.LicenseKey = "YOUR-KEY";

// Create a new Word document
WordDocument doc = new WordDocument();

// Load the image to be used as a watermark
IronWord.Models.Image image = new IronWord.Models.Image("ironword.png");

// Create an ElementPosition object to set the position
ElementPosition elementPosition = new ElementPosition();
elementPosition.SetXPosition(50);
elementPosition.SetYPosition(50);

// Set the dimensions of the image
image.Width = 50; // In pixels
image.Height = 50; // In pixels

// Set the image position using the ElementPosition object
image.Position = elementPosition;

// Offset the image from each side by 100 pixels
image.DistanceFromTop = 100;
image.DistanceFromBottom = 100;
image.DistanceFromLeft = 100;
image.DistanceFromRight = 100;

Imports IronWord
Imports IronWord.Models

' Set the license key
IronWord.License.LicenseKey = "YOUR-KEY"

' Create a new Word document
Dim doc As New WordDocument()

' Load the image to be used as a watermark
Dim image As New IronWord.Models.Image("ironword.png")

' Create an ElementPosition object to set the position
Dim elementPosition As New ElementPosition()
elementPosition.SetXPosition(50)
elementPosition.SetYPosition(50)

' Set the dimensions of the image
image.Width = 50 ' In pixels
image.Height = 50 ' In pixels

' Set the image position using the ElementPosition object
image.Position = elementPosition

' Offset the image from each side by 100 pixels
image.DistanceFromTop = 100
image.DistanceFromBottom = 100
image.DistanceFromLeft = 100
image.DistanceFromRight = 100

Similar to the code above, we set the dimensions of the image's x and y locations to 50. We also offset the dimensions from each side by 100px to create a margin around it.