Blazor-Color-Picker

Sometimes HTML5 colorpicker doesn't suit me for an application. I prefer to offer the user a predefined color palette

DEMO : https://tossnet.github.io/Blazor-Color-Picker/

Opens a palette with the Material colors

Installation

[!WARNING] The implementation has been improved: version 4.0 uses a service declared via dependency injection

Latest version in here:

To Install

Install-Package BlazorColorPicker

or

dotnet add package BlazorColorPicker

For client-side and server-side Blazor - add script section to index.html or _Host.cshtml (head section)

<link href="_content/BlazorColorPicker/colorpicker.css" rel="stylesheet" />

In program.cs, declare

builder.Services.AddColorPicker();

ColorPicker are rendered by the <BlazorColorPicker.ColorPicker />. This component needs to be added to the main layout of your application/site. You typically do this in the MainLayout.razor file at the end of the

section.

Usage

@page "/" @using BlazorColorPicker @inject IColorPickerService ColorPickerService <button class="btn btn-primary" @onclick="OpenModal"> <div style="background-color:@color" class="buttonColor"></div> Select a Color </button> @code { private string color = "#F1F7E9"; private async Task OpenModal() { var parameters = new ColorPickerParameters { ColorSelected = color, }; color = await ColorPickerService.ShowColorPicker(parameters); } }

Find Closest Color

When the selected color doesn't exist in the palette, you can enable automatic matching to the closest available color using the FindClosestIfNotFound parameter:

var parameters = new ColorPickerParameters { ColorSelected = "#8B4513", // SaddleBrown - not in the default palette FindClosestIfNotFound = true, }; color = await ColorPickerService.ShowColorPicker(parameters);

The algorithm uses a weighted Euclidean distance in RGB color space, which accounts for human color perception (green differences are more noticeable than red or blue).

[!NOTE] Color comparison is case-insensitive: #ec407a will match #EC407A in the palette.

Release Notes

Version 4.2.0

• New feature: FindClosestIfNotFound parameter - when the selected color is not in the palette, automatically highlights the closest matching color
• Color comparison is now case-insensitive (#ec407a matches #EC407A)
• Uses weighted Euclidean distance algorithm for perceptually accurate color matching

Version 4.1.1

• Performance & memory optimization: default colors are now static and shared across all instances
• Fixed memory leak in OnParametersSet() that caused unbounded list growth
• Zero allocations when using default color palette

Version 4.0.2

>- Added AddColorPicker() to simplify declaration

Version 4.0.1

>- increase the z-index to 9999

Version 4.0.0

>- the implementation has been improved: version 4.0 uses a service declared via dependency injection

⚠️ Breaking changes ⚠️

Version 3.1.0

>- you can customise the size of the palette using your CSS styles >- A red colour of the first column was not correct >- Re-addition of .NET7 compatibility

Version 2.2.0

• Remove the internal use of IJSRuntime

Version 2.1.0

• no need to declare the _content/BlazorColorPicker/colorpicker.js file