Blazor - Get Started with CheckBox

Blazor - Get Started with Smart.CheckBox

Setup The Project

Follow the Getting Started guide to set up your Blazor Application with Smart UI.

Setup Basic CheckBox

Smart.CheckBox is a custom checkbox element with built-in features such as animations, image support and checkMode.
It is recommended to use Smart.CheckBox in forms with multiple options and Smart.SwitchButton in single settings option.

  1. Add the CheckBox component to the Pages/Index.razor file
  2. Optionally, set the label, value and check state of the CheckBox:
    <CheckBox Name="Interests" Value="Music" Checked="true">Music</CheckBox>
Basic CheckBox

Check Mode

Check Mode determines the behavior of the element when clicking on the input and the label. When CheckMode is set to Both - it can be selected by both parts of the component. In the example below, the checkbox can only be selected by clicking on the label:

<CheckBox Name="Subscribe" Value="newsletter" Checked="true" CheckMode="CheckMode.Label">Subscribe to newsletter?</CheckBox>
CheckBox check mode

CheckBox with Image

Smart.CheckBox supports applying custom images with CSS:

  smart-check-box.heart .smart-input {
    background-image: url(;
    background-repeat: no-repeat;
    border-color: transparent;
    background-color: transparent;	

  smart-check-box.heart .smart-input::after {
    content: '';

  smart-check-box.heart .smart-overlay {

  smart-check-box.heart[checked] .smart-input {
    background-image: url(;
    background-repeat: no-repeat;
    color: var(--smart-error);

  smart-check-box.heart[checked="null"] .smart-input {
    background-image: url(;
    background-repeat: no-repeat;
<CheckBox Name="Interests" Value="Music" Checked="true" Class="heart">Music</CheckBox>
<CheckBox Name="Interests" Value="Books" Checked="true"Class="heart">Books</CheckBox>
CheckBox with images

CheckBox Events

Smart.CheckBox provides multiple events that can help you expand the component's functionality.
Each event object has unique event.detail parameters.

  • OnChange - triggered when the widget is checked/unchecked.
    Event Details: dynamic value, dynamic oldValue, dynamic changeType
  • OnCheckValue - triggered when the component is checked.
    Event Details: dynamic changeType
  • OnUncheckValue - triggered when the component is unchecked.
    Event Details: dynamic changeType

The demo below uses the OnCheckValue Event to log every time the checkbox is checked:

<CheckBox Name="Subscribe" Checked="true" OnCheckValue="OnCheckValue">Subscribe to newsletter?</CheckBox>

    string message = "";
    private void OnCheckValue(Event ev){
        message += "Checked!, ";
CheckBox OnCheckValue event

Two-way Value Binding

The CheckBox component also supports two-way value binding:

<CheckBox @bind-Checked="@CheckBoxValue">Subscribe to newsletter?</CheckBox>

    public bool CheckBoxValue = true;
CheckBox value binding