Insert Images Dynamically Leave feedback

Overview

GroupDocs.Assembly for .NET allows you to insert images dynamically into documents using image tags. Images can be loaded from file paths, URLs, streams, byte arrays, or Base64-encoded strings, making it easy to include dynamic images in your reports.

The main classes involved are:

DocumentAssembler - assembles documents
DataSourceInfo - wraps data sources

Here are the steps to insert images dynamically:

Add a textbox to your template at the location where you want the image
Set the textbox size and appearance to match desired image dimensions
Insert an image tag <<image [expression]>> within the textbox
Provide image data from file path, URL, stream, or byte array
Assemble the document

Note
Image tags are replaced with actual images during document assembly. The textbox acts as a placeholder and container for the image.

Insert Image from File Path

Insert an image from a file path:

using GroupDocs.Assembly;

public class Product
{
    public string Name { get; set; }
    public string ImagePath { get; set; }
}

public static void InsertImageFromFilePath()
{
    // Sample data with image path
    var product = new Product
    {
        Name = "Laptop",
        ImagePath = @"C:\Images\laptop.jpg"
    };
    
    // Assemble document
    DocumentAssembler assembler = new DocumentAssembler();
    assembler.AssembleDocument("ImageTemplate.docx", "ImageOutput.docx", 
        new DataSourceInfo(product, "product"));
    
    Console.WriteLine("Image inserted from file path successfully.");
}

Template Structure for Images

In your template (ImageTemplate.docx):

Insert a textbox where you want the image
Set the textbox size (width and height)
Add the image tag inside the textbox:

Product: <<[product.Name]>>

[Textbox with image tag:]
<<image [product.ImagePath]>>

Insert Image from URL

Insert an image from a URL:

using GroupDocs.Assembly;

public class Product
{
    public string Name { get; set; }
    public string ImageUrl { get; set; }
}

public static void InsertImageFromUrl()
{
    var product = new Product
    {
        Name = "Laptop",
        ImageUrl = "https://example.com/images/laptop.jpg"
    };
    
    DocumentAssembler assembler = new DocumentAssembler();
    assembler.AssembleDocument("ImageTemplate.docx", "ImageOutput.docx", 
        new DataSourceInfo(product, "product"));
    
    Console.WriteLine("Image inserted from URL successfully.");
}

Template:

Product: <<[product.Name]>>

[Textbox:]
<<image [product.ImageUrl]>>

Insert Image from Byte Array

Insert an image from binary data:

using GroupDocs.Assembly;
using System.IO;

public class Product
{
    public string Name { get; set; }
    public byte[] ImageData { get; set; }
}

public static void InsertImageFromByteArray()
{
    // Load image into byte array
    byte[] imageBytes = File.ReadAllBytes(@"C:\Images\laptop.jpg");
    
    var product = new Product
    {
        Name = "Laptop",
        ImageData = imageBytes
    };
    
    DocumentAssembler assembler = new DocumentAssembler();
    assembler.AssembleDocument("ImageTemplate.docx", "ImageOutput.docx", 
        new DataSourceInfo(product, "product"));
    
    Console.WriteLine("Image inserted from byte array successfully.");
}

Template:

Product: <<[product.Name]>>

[Textbox:]
<<image [product.ImageData]>>

Insert Image from Stream

Insert an image from a stream:

using GroupDocs.Assembly;
using System.IO;

public class Product
{
    public string Name { get; set; }
    public Stream ImageStream { get; set; }
}

public static void InsertImageFromStream()
{
    using (FileStream imageStream = new FileStream(@"C:\Images\laptop.jpg", FileMode.Open))
    {
        var product = new Product
        {
            Name = "Laptop",
            ImageStream = imageStream
        };
        
        DocumentAssembler assembler = new DocumentAssembler();
        assembler.AssembleDocument("ImageTemplate.docx", "ImageOutput.docx", 
            new DataSourceInfo(product, "product"));
        
        Console.WriteLine("Image inserted from stream successfully.");
    }
}

Image Sizing Options

Control how images are sized within textboxes:

using GroupDocs.Assembly;

public static void InsertImageWithSizing()
{
    var product = new Product
    {
        Name = "Laptop",
        ImagePath = @"C:\Images\laptop.jpg"
    };
    
    DocumentAssembler assembler = new DocumentAssembler();
    assembler.AssembleDocument("ImageTemplate.docx", "ImageOutput.docx", 
        new DataSourceInfo(product, "product"));
    
    Console.WriteLine("Image inserted with sizing options.");
}

Template sizing options:

<<image [product.ImagePath]>> - Stretch to fill textbox (default)
<<image [product.ImagePath] -keepRatio>> - Keep aspect ratio within textbox
<<image [product.ImagePath] -fitHeight>> - Fit to textbox height
<<image [product.ImagePath] -fitWidth>> - Fit to textbox width
<<image [product.ImagePath] -fitSize>> - Resize textbox to image size
<<image [product.ImagePath] -fitSizeLim>> - Resize textbox up to image size

Insert Multiple Images from Collection

Insert images for each item in a collection:

using GroupDocs.Assembly;
using System.Collections.Generic;

public static void InsertImagesFromCollection()
{
    List<Product> products = new List<Product>
    {
        new Product { Name = "Laptop", ImagePath = @"C:\Images\laptop.jpg" },
        new Product { Name = "Mouse", ImagePath = @"C:\Images\mouse.jpg" }
    };
    
    DocumentAssembler assembler = new DocumentAssembler();
    assembler.AssembleDocument("ImagesTemplate.docx", "ImagesOutput.docx", 
        new DataSourceInfo(products, "products"));
    
    Console.WriteLine("Images inserted from collection successfully.");
}

Template with foreach:

<<foreach [in products]>>
Product: <<[Name]>>

[Textbox:]
<<image [ImagePath]>>

<</foreach>>

Warning
If an image expression returns a stream, the stream is automatically closed by the assembler after the image is loaded. Do not dispose the stream manually.

Advanced Usage Topics

To learn more about image formatting, Base64-encoded images, image optimization, and advanced image handling, please refer to the advanced usage section.

More resources

GitHub Examples

You may easily run the code above and see the feature in action in our GitHub examples:

Free Online Apps

Along with the full-featured .NET library, we provide simple but powerful free online apps.

To assemble documents from templates and data sources, you can use the online apps from the GroupDocs.Assembly App Product Family.

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