Advanced usage QR Code renderers

1. Introduction to the "QR Code Renderers"
2. Overview of the different Renderers
   2.1. QRCode-Renderer in detail
   2.2. AsciiQRCode-Renderer in detail
   2.3. Base64QRCode-Renderer in detail
   2.4. BitmapByteQRCode-Renderer in detail
   2.5. PngByteQRCode-Renderer in detail
   2.6. SvgQRCode-Renderer in detail
   2.7. UnityQRCode-Renderer in detail
   2.8. XamlQRCode-Renderer in detail
   2.9. PostscriptQRCode-Renderer in detail
   2.10. PdfByteQRCode-Renderer in detail
   2.11. ArtQRCode-Renderer in detail

1. Introduction to the "QR Code Renderers"

As explained in the architectural overview, the QRCoder separates data/information from output/representation. So in data/core layer you create the QR Code information:

CodeGenerator qrGenerator = new QRCodeGenerator();
QRCodeData qrCodeData = qrGenerator.CreateQrCode("The payload aka the text which should be encoded.", QRCodeGenerator.ECCLevel.Q);

Now you have to bring this information into a representation you like - or better said - you have to convert this information into the output format you like. Therefore you can use the so called "QR Code renderers". This are classes of the QRCoder which help you to represent that QrCodeData the way you prefer. Each renderer-class has a function called "GetGraphic" which returns the graphical representation of the QR Code.

Before we have a look at each of the renderers, let's have a quick look onto the following comparison table which shows the benefits of each of the renderer classes.

2. Overview of the different Renderers

The following table gives an overview of which renderer is available on which target platforms and which datatype it generates.

Name	Output Format	.NET3.5+	.NET4.0+	.NET5.0	.NET5.0-windows	.NET6.0	.NET6.0-windows	.NETStandard1.3+	.NETStandard2.0+
QRCode	Bitmap-object (System.Drawing.Bitmap)	✔	✔	✔	✔	❌	✔	❌	✔
AsciiQrCode	String (QR Code encoded as ASCII chars)	✔	✔	✔	✔	✔	✔	✔	✔
Base64QRCode	String (QR Code encoded as Base64)	✔	✔	✔	✔	✔(1)	✔	❌	✔
BitmapByteQRCode	Byte-Array containing raw Bitmap	✔	✔	✔	✔	✔	✔	✔	✔
PngByteQRCode	Byte-Array containing raw PNG image	✔	✔	✔	✔	✔	✔	✔	✔
SvgQRCode	String (QR Coded as SVG vector graphic)	✔	✔	✔	✔	✔	✔	❌	✔
UnityQRCode (via QRCoder.Unity nuget-package)	Texture2D (UnityEngine.Texture2D)	✔	✔	❌	❌	❌	❌	❌	❌
XamlQRCode (via QRCoder.Xaml nuget-package)	DrawingImage (for usage in WPF, Silverlight, etc.)	✔	✔	❌	✔	❌	✔	❌	❌
PostscriptQRCode	String (QR code encoded as PS/EPS string.)	✔	✔	✔	✔	✔	✔	❌	✔
PdfByteQRCode	Byte-Array containing raw PDF document	✔	✔	✔	✔	❌	✔	❌	✔
ArtQRCode	Bitmap-object (System.Drawing.Bitmap)	✔	✔	✔	✔	❌	✔	❌	✔

⁽¹⁾ On platforms other than Windows only PNG is supported in Base64QRCode

2.1 QRCode-Renderer in detail

Classname/Classfile: QRCode/QRCode.cs

When to use?

Use it if you want a pixel-based image (=Bitmap) and if you are working with .NET Framework. Use it if you want to show the QR Code in your app, save the QR Code as image file or deliver the QR Code as download.

How to use it - simple way

QRCodeGenerator qrGenerator = new QRCodeGenerator();
QRCodeData qrCodeData = qrGenerator.CreateQrCode("The text which should be encoded.", QRCodeGenerator.ECCLevel.Q);
QRCode qrCode = new QRCode(qrCodeData);
Bitmap qrCodeImage = qrCode.GetGraphic(20);

Parameter table

There are four different overloads:

Overload 1 (Return type: Bitmap)

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel size each b/w module is drawn

Overload 2 (Return type: Bitmap)

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel size each b/w module is drawn
darkColor	Color		The color of the dark/black modules
lightColor	Color		The color of the light/white modules
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code

Overload 3 (Return type: Bitmap)

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel size each b/w module is drawn
darkColorHtmlHex	string		The color of the dark/black modules in hex (e.g. #000000) representation
lightColorHtmlHex	string		The color of the light/white modules in hex (e.g. #ffffff) representation
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code

Overload 4 (Return type: Bitmap)

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel size each b/w module is drawn
darkColor	Color		The color of the dark/black modules
lightColor	Color		The color of the light/white modules
icon	Bitmap	null	If null, then ignored. If set, the Bitmap is drawn in the middle of the QR Code
iconSizePercent	int	15	Value from 1-99. Sets how much % of the QR Code will be covered by the icon
iconBorderWidth	int	6	Width of the border which is drawn around the icon. Minimum: 1
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code
iconBackgroundColor	Color?	null	Defines the background color of the icon. If null(=default) the value of lightColoris used. (Icon background is only rendered and thus iconBackgroundColor is only used, if parameter icon != null and iconBorderWidth > 0.)

Good to know

This renderer is the way to go, if you want to draw an icon onto the QR Code.In most cases this renderer fits the needs very well.

2.2 AsciiQRCode-Renderer in detail

Classname/Classfile: ASCIIQRCode / ASCIIQRCode.cs

When to use?

Useful for web-, retro- and console-environments. By use of this encoder you get a QR code encoded as string just build out of chars. By default UTF-8 block symbols are used.

Trivia: The renderer is called Ascii renderer, although it uses characters from the Utf-8 character set by default. The idea behind this is that the renderer uses a text-based graphical representation that is reminiscent of classic Ascii art. Naming it Utf8QrCode was rejected in the design phase, as it would be difficult to deduce from this name what type of return value the renderer has.

How to use it - simple way

QRCodeGenerator qrGenerator = new QRCodeGenerator();
QRCodeData qrCodeData = qrGenerator.CreateQrCode("The text which should be encoded.", QRCodeGenerator.ECCLevel.Q);
AsciiQRCode qrCode = new AsciiQRCode(qrCodeData);
string qrCodeAsAsciiArt = qrCode.GetGraphic(1);

Parameter table

There are three different overloads:

Overload 1 (Return type: string)

Parameter name	Type	Default	Description
repeatPerModule	int		Number of repeated darkColorString/whiteSpaceString per module. (Must be 1 or greater.)
darkColorString	string	██	String for use as dark color modules. In case of string make sure whiteSpaceString has the same length.
whiteSpaceString	string		String for use as white modules (whitespace). In case of string make sure darkColorString has the same length.
drawQuietZones	bool	true	If true a white border is "drawn" around the whole QR Code
endOfLine	string	\n	End of line separator.

Overload 2 (Functionname: GetLineByLineGraphic, Return type: string[])

Parameter name	Type	Default	Description
repeatPerModule	int		Number of repeated darkColorString/whiteSpaceString per module.
darkColorString	string	██	String for use as dark color modules. In case of string make sure whiteSpaceString has the same length.
whiteSpaceString	string		String for use as white modules (whitespace). In case of string make sure darkColorString has the same length.
drawQuietZones	bool	true	If true a white border is "drawn" around the whole QR Code.

Overload 3 (Functionname: GetGraphicSmall, Return type: string)

Parameter name	Type	Default	Description
drawQuietZones	bool	true	If true a border is "drawn" around the whole QR Code.
invert	bool	false	If set to true, light- and dark color will be switched.
endOfLine	string	\n	End of line separator.

Good to know

If you set darkColorString or whiteSpaceString you have to ensure that they are both of the same length. Also you should keep in mind that this type of rendering only works when shown in a so called "Monospace" font. If you need a smaller representation than GetGraphic with repeatPerModule: 1, use GetGraphicSmall which compresses two module lines into one character line each.

2.3 Base64QRCode-Renderer in detail

Classname/Classfile: Base64QRCode / Base64QRCode.cs

When to use?

Usually very helpful in web and database environments. You can embed the Base64 images into html code, easily trafer them via HTTP requests or write them into databases without any hassle.

How to use it - simple way

QRCodeGenerator qrGenerator = new QRCodeGenerator();
QRCodeData qrCodeData = qrGenerator.CreateQrCode("The text which should be encoded.", QRCodeGenerator.ECCLevel.Q);
Base64QRCode qrCode = new Base64QRCode(qrCodeData);
string qrCodeImageAsBase64 = qrCode.GetGraphic(20);

Parameter table

There are four different overloads:

Overload 1 (Return type: string)

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel size each b/w module is drawn

Overload 2 (Return type: string)

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel size each b/w module is drawn
darkColor	Color		The color of the dark/black modules
lightColor	Color		The color of the light/white modules
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code
imgType	Base64QRCode.ImageType	Base64QRCode.ImageType.Png	Sets the image format of the image which is encoded in the Base64 string

Overload 3 (Return type: string)

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel size each b/w module is drawn
darkColorHtmlHex	string		The color of the dark/black modules in hex (e.g. #000000) representation
lightColorHtmlHex	string		The color of the light/white modules in hex (e.g. #ffffff) representation
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code
imgType	Base64QRCode.ImageType	Base64QRCode.ImageType.Png	Sets the image format of the image which is encoded in the Base64 string

Overload 4 (Return type: string)

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel size each b/w module is drawn
darkColor	Color		The color of the dark/black modules
lightColor	Color		The color of the light/white modules
icon	Bitmap	null	If null, then ignored. If set, the Bitmap is drawn in the middle of the QR Code
iconSizePercent	int	15	Value from 1-99. Sets how much % of the QR Code will be covered by the icon
iconBorderWidth	int	6	Width of the border which is drawn around the icon. Minimum: 1
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code
imgType	Base64QRCode.ImageType	Base64QRCode.ImageType.Png	Sets the image format of the image which is encoded in the Base64 string

Good to know

The string returned by the GetGraphic-method just contains the image as Base64 string. It does not contain any HTML tags, etc. If you like to embed the image for example, you have to add the img-tag. E.g.

//...
var imgType = Base64QRCode.ImageType.Jpeg;
Base64QRCode qrCode = new Base64QRCode(qrCodeData);
string qrCodeImageAsBase64 = qrCode.GetGraphic(20,Color.Black, Color.White, true, imgType);
var htmlPictureTag =  $"<img alt=\"Embedded QR Code\" src=\"data:image/{imgType.ToString().ToLower()};base64,{qrCodeImageAsBase64}\" />";

2.4 BitmapByteQRCode-Renderer in detail

Classname/Classfile: BitmapByteQRCode / BitmapByteQRCode.cs

When to use?

When using the PCL version of the QRCoder (e.g. in mobile projects) this is, besides PngByteQRCode, the only available renderer. It returns the QR code as byte-array which contains a Bitmap graphic. Since many of the platforms where the PCL library is available have different implementations of Bitmap class, but nearly any platform can create an image from byte[], this is some way of dealing with images cross-platforms.

How to use it - simple way

QRCodeGenerator qrGenerator = new QRCodeGenerator();
QRCodeData qrCodeData = qrGenerator.CreateQrCode("The text which should be encoded.", QRCodeGenerator.ECCLevel.Q);
BitmapByteQRCode qrCode = new BitmapByteQRCode(qrCodeData);
byte[] qrCodeAsBitmapByteArr = qrCode.GetGraphic(20);

//From here on, you can implement your platform-dependent byte[]-to-image code 

//e.g. Windows 10 - Full .NET Framework
Bitmap bmp;
using (var ms = new MemoryStream(qrCodeAsBitmapByteArr))
{
    qrCodeImage = new Bitmap(ms);
}

//e.g. Windows 10 Universal App (UAP)
using (InMemoryRandomAccessStream stream = new InMemoryRandomAccessStream())
{
    using (DataWriter writer = new DataWriter(stream.GetOutputStreamAt(0)))
    {
        writer.WriteBytes(qrCodeImage);
        await writer.StoreAsync();
    }
    var image = new BitmapImage();
    await image.SetSourceAsync(stream);

    imageViewer.Source = image;
}

Parameter table

There are two overloads:

Overload 1 (Return type: byte[])

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel size each b/w module is drawn

Overload 2 (Return type: byte[])

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel size each b/w module is drawn
darkColorRgba	byte[]		The color of the dark modules, as RGB array
lightColorRgba	byte[]		The color of the light modules, as RGB array

Good to know

Since this method shall be 100% platform independent the Bitmap in the byte[] is created manually byte by byte. So this renderer doesn't offer any fancy parameters right now. If you are an Bitmap expert feel free to improve the code. If you aren't but want a cool QR code, use the QR code module matrix and create your own renderer.

2.5 PngByteQRCode-Renderer in detail

Classname/Classfile: PngByteQRCode / PngByteQRCode.cs

When to use?

When using the PCL version of the QRCoder (e.g. in mobile projects) this is, besides BitmapByteQRCode, the available renderer. It returns the QR code as byte-array which contains a PNG graphic. Since many of the platforms where the PCL library is available have different implementations of Imaging classes, but nearly any platform can create an image from byte[] (or write a byte-array to file), this is some way of dealing with images cross-platforms.

How to use it - simple way

QRCodeGenerator qrGenerator = new QRCodeGenerator();
QRCodeData qrCodeData = qrGenerator.CreateQrCode("The text which should be encoded.", QRCodeGenerator.ECCLevel.Q);
PngByteQRCode qrCode = new PngByteQRCode(qrCodeData);
byte[] qrCodeAsPngByteArr = qrCode.GetGraphic(20);

//From here on, you can implement your platform-dependent byte[]-to-image code 

//e.g. Windows 10 - Full .NET Framework
Bitmap bmp;
using (var ms = new MemoryStream(qrCodeAsPngByteArr))
{
    qrCodeImage = new Bitmap(ms);
}

//e.g. Windows 10 Universal App (UAP)
using (InMemoryRandomAccessStream stream = new InMemoryRandomAccessStream())
{
    using (DataWriter writer = new DataWriter(stream.GetOutputStreamAt(0)))
    {
        writer.WriteBytes(qrCodeAsPngByteArr);
        await writer.StoreAsync();
    }
    var image = new BitmapImage();
    await image.SetSourceAsync(stream);

    imageViewer.Source = image;
}

Parameter table

There are two overloads:

Overload 1 (Return type: byte[])

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel size each b/w module is drawn
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code

Overload 2 (Return type: byte[])

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel size each b/w module is drawn
darkColorRgba	byte[]		The color of the dark modules, as RGB(A) array
lightColorRgba	byte[]		The color of the light modules, as RGB(A) array
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code

Good to know

Since this method shall be 100% platform independent the Png in the byte[] is created manually byte by byte. So this renderer doesn't offer any fancy parameters right now. If you are an Png expert feel free to improve the code. If you aren't but want a cool QR code, use the QR code module matrix and create your own renderer.

2.6 SvgQRCode-Renderer in detail

Classname/Classfile: SvgQRCode / SvgQRCode.cs

When to use?

Use this if you want to print the QR code in a huge size or when dealing with scalable (in sense of screensize) web applications. The SvgQRCode returns a scalable vector graphic which never gets blurry by its nature.

How to use it - simple way

QRCodeGenerator qrGenerator = new QRCodeGenerator();
QRCodeData qrCodeData = qrGenerator.CreateQrCode("The text which should be encoded.", QRCodeGenerator.ECCLevel.Q);
SvgQRCode qrCode = new SvgQRCode(qrCodeData);
string qrCodeAsSvg = qrCode.GetGraphic(20);

Parameter table

There are six overloads:

Overload 1 (Return type: string)

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel per b/w QR code module. This x module count = ViewBox size

Overload 2 (Return type: string)

Parameter name	Type	Default	Description
viewBox	Size		Size of the SVG viewbox
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code
sizingMode	SizingMode	SizingMode.WidthHeightAttribute	Changes how the size attributes of main <svg>-tag are created. Either width="xxx" height="xxx" (=SizingMode.WidthHeightAttribute) or viewBox="0 0 xxx xxx" (=SizingMode.ViewBoxAttribute) is used.
logo	SvgLogo	null	An optional logo (svg or bitmap) to be rendered on the QR code

Overload 3 (Return type: string)

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel per b/w QR code module. This x module count = ViewBox size
darkColor	Color		The color of the dark/black modules
lightColor	Color		The color of the light/white modules
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code
sizingMode	SizingMode	SizingMode.WidthHeightAttribute	Changes how the size attributes of main <svg>-tag are created. Either width="xxx" height="xxx" (=SizingMode.WidthHeightAttribute) or viewBox="0 0 xxx xxx" (=SizingMode.ViewBoxAttribute) is used.
logo	SvgLogo	null	An optional logo (svg or bitmap) to be rendered on the QR code

Overload 4 (Return type: string)

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel per b/w QR code module. This x module count = ViewBox size
darkColorHtmlHex	string		The color of the dark/black modules in hex (e.g. #000000) representation
lightColorHtmlHex	string		The color of the light/white modules in hex (e.g. #ffffff) representation
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code
sizingMode	SizingMode	SizingMode.WidthHeightAttribute	Changes how the size attributes of main <svg>-tag are created. Either width="xxx" height="xxx" (=SizingMode.WidthHeightAttribute) or viewBox="0 0 xxx xxx" (=SizingMode.ViewBoxAttribute) is used.
logo	SvgLogo	null	An optional logo (svg or bitmap) to be rendered on the QR code

Overload 5 (Return type: string)

Parameter name	Type	Default	Description
viewBox	Size		Size of the SVG viewbox
darkColor	Color		The color of the dark/black modules
lightColor	Color		The color of the light/white modules
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code
sizingMode	SizingMode	SizingMode.WidthHeightAttribute	Changes how the size attributes of main <svg>-tag are created. Either width="xxx" height="xxx" (=SizingMode.WidthHeightAttribute) or viewBox="0 0 xxx xxx" (=SizingMode.ViewBoxAttribute) is used.
logo	SvgLogo	null	An optional logo (svg or bitmap) to be rendered on the QR code

Overload 6 (Return type: string)

Parameter name	Type	Default	Description
viewBox	Size		Size of the SVG viewbox
darkColorHtmlHex	string		The color of the dark/black modules in hex (e.g. #000000) representation
lightColorHtmlHex	string		The color of the light/white modules in hex (e.g. #ffffff) representation
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code
sizingMode	SizingMode	SizingMode.WidthHeightAttribute	Changes how the size attributes of main <svg>-tag are created. Either width="xxx" height="xxx" (=SizingMode.WidthHeightAttribute) or viewBox="0 0 xxx xxx" (=SizingMode.ViewBoxAttribute) is used.
logo	SvgLogo	null	An optional logo (svg or bitmap) to be rendered on the QR code

Good to know

The string returned just contains the plain SVG. You can save it to file via StreamWriter-class or File.WriteAllText-method or you can embed into a website. But don't forget to write the correct tags around the SVG string. (Have a look here.)

2.7 UnityQRCode-Renderer in detail

Classname/Classfile: (external) See QRCoder.Unity-repository

When to use?

Use this renderer if you are working on an Unity-based app or game. This renderer return a Texture2D object for easier handling. It saves you some time, compared to the other renders.

How to use it - simple way

Install via Nuget: PM> Install-Package QRCoder.Unity
(QRCoder.Unity@nuget)

QRCodeGenerator qrGenerator = new QRCodeGenerator();
QRCodeData qrCodeData = qrGenerator.CreateQrCode("The text which should be encoded.", QRCodeGenerator.ECCLevel.Q);
UnityQRCode qrCode = new UnityQRCode(qrCodeData);
Texture2D qrCodeAsTexture2D = qrCode.GetGraphic(20);

Parameter table

There are 3 overloads:

Overload 1 (Return type: Texture2D)

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel size each b/w module is drawn

Overload 2 (Return type: Texture2D)

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel size each b/w module is drawn
darkColorHtmlHex	string		The color of the dark/black modules in hex (e.g. #000000) representation
lightColorHtmlHex	string		The color of the light/white modules in hex (e.g. #ffffff) representation

Overload 3 (Return type: Texture2D)

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel size each b/w module is drawn
darkColor	UnityEngine.Color		The color of the dark/black modules
lightColor	UnityEngine.Color		The color of the light/white modules

Good to know

This renderer is some kind of experimental. There are some reports that it sometimes is buggy on iOS devices, whilst Android, Windows and Linux should be working fine. So please test your project in an appropriate manner when using this renderer.

2.8 XamlQRCode-Renderer in detail

Classname/Classfile: XamlQRCode / XamlQRCode.cs

When to use?

Use this if you want to print the QR code in an XAML application (e.g. WPF, Silverlight). The XamlQRCode returns a scalable vector XAML object tree which never gets blurry by its nature.

How to use it - simple way

Install via Nuget: PM> Install-Package QRCoder.Xaml
(QRCoder.Xaml@nuget)

QRCodeGenerator qrGenerator = new QRCodeGenerator();
QRCodeData qrCodeData = qrGenerator.CreateQrCode("The text which should be encoded.", QRCodeGenerator.ECCLevel.Q);
XamlQRCode qrCode = new XamlQRCode(qrCodeData);
DrawingImage qrCodeAsXaml = qrCode.GetGraphic(20);

Parameter table

There are five overloads:

Overload 1 (Return type: System.Windows.Media.DrawingImage)

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel per b/w QR code module. This x module count = ViewBox size

Overload 2 (Return type: System.Windows.Media.DrawingImage)

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel per b/w QR code module. This x module count = ViewBox size
drawQuietZones	bool		If true a white border is drawn around the whole QR Code

Overload 3 (Return type: System.Windows.Media.DrawingImage)

Parameter name	Type	Default	Description
viewBox	Size		Size of the SVG viewbox
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code

Overload 4 (Return type: System.Windows.Media.DrawingImage)

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel per b/w QR code module. This x module count = ViewBox size
darkColorHex	string		The color of the dark/black modules in hex (e.g. #000000) representation
lightColorHex	string		The color of the light/white modules in hex (e.g. #ffffff) representation
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code

Overload 5 (Return type: System.Windows.Media.DrawingImage)

Parameter name	Type	Default	Description
viewBox	Size		Size of the SVG viewbox
darkBrush	Brush		The brush of the dark/black modules
lightBrush	Brush		The brush of the light/white modules
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code

Good to know

The object tree returned can be assigned to an System.Windows.Controls.Image (<Image> in XAML) element's Source property. In the MVVM approach, the Source property can be bound to a model's string property and QR generation code can be implemented as an IValueConverter to convert a string value to QR code and return the System.Windows.Media.DrawingImage generated.

The <Image> element uses anti-aliased rendering by default, which makes the readability of a QR code worse. In order to display it with aliased rendering, set the RenderOptions.EdgeMode attached property to "Aliased".

2.9 PostscriptQRCode-Renderer in detail

Classname/Classfile: PostscriptQRCode / PostscriptQRCode.cs

When to use?

Use this if you want to print the QR code on a postscript printer or if you want to create a pdf file.

How to use it - simple way

QRCodeGenerator qrGenerator = new QRCodeGenerator();
QRCodeData qrCodeData = qrGenerator.CreateQrCode("The text which should be encoded.", QRCodeGenerator.ECCLevel.Q);
PostscriptQRCode qrCode = new PostscriptQRCode(qrCodeData);
string qrCodeAsPostscript = qrCode.GetGraphic(20);

Parameter table

There are six overloads:

Overload 1 (Return type: string)

Parameter name	Type	Default	Description
pointsPerModule	int		The point per b/w QR code module. This x module count = ViewBox size
epsMode	bool	false	If true, create the file as Encapsulated Postscript (EPS)

Overload 2 (Return type: string)

Parameter name	Type	Default	Description
viewBox	Size		Size of the Postscript viewbox
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code
epsMode	bool	false	If true create the file as Encapsulated Postscript (EPS)

Overload 3 (Return type: string)

Parameter name	Type	Default	Description
pointsPerModule	int		The point per b/w QR code module. This x module count = ViewBox size
darkColor	Color		The color of the dark/black modules
lightColor	Color		The color of the light/white modules
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code
epsMode	bool	false	If true create the file as Encapsulated Postscript (EPS)

Overload 4 (Return type: string)

Parameter name	Type	Default	Description
pointsPerModule	int		The point per b/w QR code module. This x module count = ViewBox size
darkColorHtmlHex	string		The color of the dark/black modules in hex (e.g. #000000) representation
lightColorHtmlHex	string		The color of the light/white modules in hex (e.g. #ffffff) representation
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code
epsMode	bool	false	If true create the file as Encapsulated Postscript (EPS)

Overload 5 (Return type: string)

Parameter name	Type	Default	Description
viewBox	Size		Size of the Postscript viewbox
darkColor	Color		The color of the dark/black modules
lightColor	Color		The color of the light/white modules
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code
epsMode	bool	false	If true create the file as Encapsulated Postscript (EPS)

Overload 6 (Return type: string)

Parameter name	Type	Default	Description
viewBox	Size		Size of the Postscript viewbox
darkColorHtmlHex	string		The color of the dark/black modules in hex (e.g. #000000) representation
lightColorHtmlHex	string		The color of the light/white modules in hex (e.g. #ffffff) representation
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code
epsMode	bool	false	If true create the file as Encapsulated Postscript (EPS)

Good to know

The string returned just contains the plain Postscript. You can save it to file via StreamWriter-class or File.WriteAllText-method.

2.10 PdfByteQRCode-Renderer in detail

Classname/Classfile: PdfByteQRCode / PdfByteQRCode.cs

When to use?

This renderer returns the QR code as byte-array which contains a PDF document. It is available on all platforms that support System.Drawing (e.g. .NET Framework >= 3.5, .NET Standard 2.0, ...) but isn't supported in .NET Standard 1.1 environments. Since many of the platforms have different implementations of PDF classes, but any platform can write a byte[] into a file, this is some way of dealing with PDFs cross-platforms.

How to use it - simple way

QRCodeGenerator qrGenerator = new QRCodeGenerator();
QRCodeData qrCodeData = qrGenerator.CreateQrCode("The text which should be encoded.", QRCodeGenerator.ECCLevel.Q);
PdfByteQRCode qrCode = new PdfByteQRCode(qrCodeData);
byte[] qrCodeAsPdfByteArr = qrCode.GetGraphic(20);

//From here on, you can implement your platform-dependent byte[]-to-(PDF-)file code 

Parameter table

There are two overloads:

Overload 1 (Return type: byte[])

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel size each b/w module is drawn

Overload 2 (Return type: byte[])

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel size each b/w module is drawn
darkColorHtmlHex	string		The color of the dark modules, as hex string e.g. #000000
lightColorHtmlHex	string		The color of the light modules, as hex string e.g. #ffffff
dpi	int	150	DPI (dots per inch) resolution of the PDF document
jpgQuality	long	85	Quality of the QR code graphic inside the PDF. From 1 (bad) to 100 (perfect).

Good to know

n/a

2.11 ArtQRCode-Renderer in detail

Classname/Classfile: QRCode/ArtQRCode.cs

When to use?

Use it if you want a pixel-based image (=Bitmap) with a more "artistic" style. You can set background images and define how the module are rendered. (As default they will be rendered as dots/circular).

How to use it - simple way

QRCodeGenerator qrGenerator = new QRCodeGenerator();
QRCodeData qrCodeData = qrGenerator.CreateQrCode("The text which should be encoded.", QRCodeGenerator.ECCLevel.Q);
ArtQRCode qrCode = new ArtQRCode(qrCodeData);
Bitmap qrCodeImage = qrCode.GetGraphic(10);

Parameter table

There are three different overloads:

Overload 1 (Return type: Bitmap)

Parameter name	Type	Default	Description
pixelsPerModule	int		Amount of px each dark/light module of the QR code shall take place in the final QR code image

Overload 2 (Return type: Bitmap)

Parameter name	Type	Default	Description
backgroundImage	Bitmap	null	A bitmap object that will be used as background picture

Overload 3 (Return type: Bitmap)

Parameter name	Type	Default	Description
pixelsPerModule	int		The pixel size each b/w module is drawn
darkColor	Color		Color of the dark modules
lightColor	Color		Color of the light modules
backgroundColor	Color		Color of the background
backgroundImage	Bitmap	null	A bitmap object that will be used as background picture
pixelSizeFactor	double	1.0	Value between 0.0 to 1.0 that defines how big the module dots are. The bigger the value, the less round the dots will be.
drawQuietZones	bool	true	If true a white border is drawn around the whole QR Code
quietZoneRenderingStyle	QuietZoneStyle	QuietZoneStyle.Dotted	Defines how the quiet zones shall be rendered. (Dotted or flat/filled.)
backgroundImageStyle	BackgroundImageStyle	BackgroundImageStyle.DataAreaOnly	Style of the background image (if set). Fill=spanning complete graphic; DataAreaOnly=Don't paint background into quietzone
finderPatternImage	Bitmap	null	Optional image that should be used instead of the default finder patterns

Good to know

This renderer allows the creation of visually appealing/beautiful QR codes, but it should be noted that the official QRCode standard does not provide for such a form. Depending on the background image used or if the pixelSizeFactor-value is too small, the QRCode may be recognized worse or not at all. This risk cannot be avoided and is the responsibility of the respective developer who includes the ArtQRCode in his/her application.