How to Display SQLite BLOB Images in a .NET Reporting Application

Displaying images stored as BLOBs in an SQLite database within a .NET reporting application can be challenging without the right approach. Whether you're working with invoices, product catalogs, or other data-driven reports, seamlessly integrating image data enhances report clarity and usability. In this guide, we’ll explore how to retrieve and display SQLite BLOB images in a .NET reporting application, ensuring your reports present visual data effectively. Let’s dive into the steps needed to extract, convert, and embed images into your reports with ease.

We'll go over how to display such images in your .NET reports created with ActiveReports.NET.

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We will use the SQLite Data Provider, which was introduced in ActiveReports.NET 16, to bind to our employees.sqlite database: 

We'll add a dataset as usual. Please see this page if you're unfamiliar with data binding in ActiveReports.NET. 

At this point, all you must do is set the following properties for the image control:

• Source: Database
• Value: =Fields!employeeImage.Value

If, however, you are using a prior version of ActiveReports.NET (v15 or earlier), we need a bit of code to convert the BLOB image from your SQLite database. Here's a sample code:

Public Function BlobToByte(ByVal x) As Byte()
    Dim str As String = BlobToString(x)
    Return System.Text.Encoding.Default.GetBytes(str)    
End Function
 
Public Function BlobToString(ByVal x) As String    
    Dim str As String = HexToString(x.Substring(2, x.Length - 3)) 'remove envelope sqlite 
    Return str.Substring(78, str.Length - 79) ' remove header Bitmap Image Paint.Picture
End Function
 
Function HexToString(ByVal hex As String) As String
    Dim text As New System.Text.StringBuilder(hex.Length \ 2)
    For i As Integer = 0 To hex.Length - 2 Step 2
        text.Append(Chr(Convert.ToByte(hex.Substring(i, 2), 16)))
    Next
    Return text.ToString
End Function

Place this code in the “Script” section of our RDL report:

Select the Image control on the design surface, and change its “Value” Property to:

=code.BlobToByte(Fields!Picture.Value)

This expression tells the RDL report to look in the Script section for a Function named BlobToByte, which takes the BLOB image as a parameter.

Here's how the report looks in the preview:

To see the complete implementation, download the zip file here: SqliteBlob.zip