ColorJsonConverter

Namespace: Wisej.Web.Ext.ChartJS4.Serialization

Assembly: Wisej.Web.Ext.ChartJS4 (4.1.0.0)

JSON converter for Color objects. Converts colors to RGBA format for Chart.js.

C#

public class ColorJsonConverter : JsonConverter<Color>

VB.NET

Public Class ColorJsonConverter
    Inherits JsonConverter(Of Color)

Colors are written as "rgba(r, g, b, a)" strings, with the alpha channel expressed as a value between 0 and 1 formatted with two decimals using the invariant culture. Empty and fully transparent colors are written as null. When reading, both the rgba(…) format and any HTML color (e.g. "#FF0000" or "red") are accepted.

Example:

var options = new JsonSerializerOptions();
options.Converters.Add(new ColorJsonConverter());
var json = JsonSerializer.Serialize(Color.FromArgb(128, 255, 0, 0), options);
// json == "\"rgba(255, 0, 0, 0.50)\""

Constructors

ColorJsonConverter()

Initializes a new instance of ColorJsonConverter.

Methods

Read(reader, typeToConvert, options)

Reads a Color from a JSON string value.

Parameter	Type	Description
reader	Utf8JsonReader	The reader positioned on the JSON string token.
typeToConvert	Type	The type to convert (Color).
options	JsonSerializerOptions	The serializer options in use.

Returns: Color. The parsed Color, or Empty if the value is null or empty.

Values in the rgba(r, g, b, a) format are parsed directly (the alpha value is scaled from 0–1 to 0–255); any other value is parsed with FromHtml.

Example:

var options = new JsonSerializerOptions();
options.Converters.Add(new ColorJsonConverter());
var color = JsonSerializer.Deserialize<Color>("\"rgba(0, 128, 255, 1)\"", options);

Write(writer, value, options)

Writes a Color to JSON in RGBA format.

Parameter	Type	Description
writer	Utf8JsonWriter	The writer to write the value to.
value	Color	The color to write.
options	JsonSerializerOptions	The serializer options in use.

Writes a string in the rgba(r, g, b, a) format, with the alpha channel as a 0–1 value with two decimals formatted using the invariant culture. Empty and colors with an alpha of 0 are written as null.

Example:

var options = new JsonSerializerOptions();
options.Converters.Add(new ColorJsonConverter());
var json = JsonSerializer.Serialize(Color.SteelBlue, options);
// json == "\"rgba(70, 130, 180, 1.00)\""