Indeterminate (tri-state) Checkbox for Blazor

Add nuget:

dotnet add package IndeterminateCheckboxBlazor

You don't need to register any service or do anything else in Program or Startup class. Value used for checkbox must be of type bool?.

@using IndeterminateCheckboxBlazor

<label> <IndeterminateCheckbox @bind-Value="_value" /> Checkbox </label>

@code {
    private bool? _value = false;
}

It's possible to set style and class with Style and Class properties:

<IndeterminateCheckbox @bind-Value="_value" Style="" Class="" />

To change behavior set ChangeMode property:

<IndeterminateCheckbox @bind-Value="_value" ChangeModel="ChangeMode.CheckedIndeterminateUnchecked" />

This property affects how checkbox value is changed when user clicks on it:

public enum ChangeMode
{
    CheckedUncheckedIndeterminate,
    CheckedIndeterminateUnchecked,
    CheckedUnchecked
}

See IndeterminateCheckboxBlazor.TestApp project for more usage examples.