Golang : How to generate Code 39 barcode?




Additional tutorial on how to use https://github.com/boombuler/barcode package to generate code 39 barcode. Code adapted from previous codabar tutorial.

Here you go :

 package main

 import (
 "fmt"
 "github.com/boombuler/barcode"
 "github.com/boombuler/barcode/code39"
 "github.com/disintegration/imaging"
 "github.com/llgcode/draw2d"
 "image"
 "image/color"
 "image/draw"
 "os"
 )

 func main() {

 code := "SOCKETLOOP PORT 443"

 fmt.Println("Generating code39 barcode for : ", code)

 // see https://godoc.org/github.com/boombuler/barcode/code39
 bcode, err := code39.Encode(code, false, false)

 if err != nil {
 fmt.Printf("String %s cannot be encoded\n", code)
 os.Exit(1)
 }

 // scale to 300x20
 bcode, err = barcode.Scale(bcode, 300, 20)

 if err != nil {
 fmt.Println("Code39 scaling error : ", err)
 os.Exit(1)
 }

 // now we want to append the code at the bottom
 // of the Codabar

 // Create an new image with text data
 // From https://github.com/llgcode/draw2d.samples/tree/master/helloworld
 // Set the global folder for searching fonts
 draw2d.SetFontFolder(".")

 // Initialize the graphic context on an RGBA image
 img := image.NewRGBA(image.Rect(0, 0, 250, 50))

 // set background to white
 white := color.RGBA{255, 255, 255, 255}
 draw.Draw(img, img.Bounds(), &image.Uniform{white}, image.ZP, draw.Src)

 gc := draw2d.NewGraphicContext(img)

 gc.FillStroke()

 // Set the font Montereymbi.ttf
 gc.SetFontData(draw2d.FontData{"Monterey", draw2d.FontFamilyMono, draw2d.FontStyleBold | draw2d.FontStyleItalic})
 // Set the fill text color to black
 gc.SetFillColor(image.Black)

 gc.SetFontSize(14)
 gc.FillStringAt(code, 50, 20)

 // create a new blank image with white background
 newImg := imaging.New(400, 200, color.NRGBA{255, 255, 255, 255})

 //paste the codabar to new blank image
 newImg = imaging.Paste(newImg, bcode, image.Pt(20, 50))

 //paste the text to the new blank image
 newImg = imaging.Paste(newImg, img, image.Pt(50, 90))

 err = draw2d.SaveToPngFile("./code39.png", newImg)

 if err != nil {
 fmt.Println(err)
 os.Exit(1)
 }

 // everything ok
 fmt.Println("Code39 barcode generated and saved to code39.png")

 }

Sample output :

code 39 barcode golang

References :

http://en.wikipedia.org/wiki/Code_39

  See also : Golang : Generate Codabar





By Adam Ng

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