`ToBase64String`

Sometimes it is helpful to have a text string representation of a binary file like an image. This text could be stored in a database, or directly on a web page.

With the Convert class, we have many helpful conversion utility methods. And ToBase64String helps us convert a byte array into a string with base-64 encoding.

To begin, we include the System.IO namespace—this is for the File.ReadAllBytes function. The Convert class is part of the System namespace, which is part of every VB.NET program.

Step 1 We specify the path of a binary file—in this program, we are using an image. Then we read in the file with File.ReadAllBytes.

Step 2 We invoke the ToBase64String function, which receives a byte array and returns a String.

Imports System.IO

Module Module1
    Sub Main()

        ' Step 1: specify the path of the image, and read all bytes from it.
        Dim image = "programs/adobe.png"
        Dim data = File.ReadAllBytes(image)

        ' Step 2: Call Convert.ToBase64String function.
        Dim result = Convert.ToBase64String(data)
        Console.WriteLine(result)

    End Sub
End ModuleiVBORw0KGgoAAA
...
AABJRU5ErkJggg==

Data URIs

On web pages (HTML documents) we can specify data URIs in the place of external HTTPS links. And the data returned by ToBase64String works inside these data URIs.

With .NET, we have many powerful features built into our languages, including base-64 encoding. There is no need in VB.NET to use an external library to encode images into text strings.