DxMaskedInput<T>.ValueChanging Event

Fires when the Masked Input’s value is being modified. Use this event to validate/cancel user input.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v25.2.dll

NuGet Package: DevExpress.Blazor

Declaration

[Parameter]
public Action<ParameterValueChangingEventArgs<T>> ValueChanging { get; set; }

Event Data

The ValueChanging event's data class is ParameterValueChangingEventArgs<T>. The following properties provide information specific to this event:

Property	Description
NewValue	Gets or sets the new value being assigned to the parameter.
OldValue	Gets the current parameter value.

Remarks

The ValueChanging event fires before a new value is applied to the editor (before the ValueChanged event). You can use this event to validate/cancel user input.

The following code snippet applies the Currency mask and handles the ValueChanging event to limit the value range (0 - 1000). The current value is updated via two-way binding (@bind-Value).

<DxMaskedInput @bind-Value="@Amount"
               ValueChanging="@OnValueChanging"
               Mask="@NumericMask.Currency">
</DxMaskedInput>

<div class="mt-2">
    <span>Current amount: @Amount.ToString("C")</span>
</div>

@code {
    decimal Amount { get; set; }

    private void OnValueChanging(ParameterValueChangingEventArgs<decimal> e) {
        if (e.NewValue < 0 || e.NewValue > 1000) {
            e.NewValue = e.OldValue;
        }
    }
}