RangeValidator

The RangeValidator component validates that user input falls within a specified range of values. This is useful for ensuring numeric values, dates, or strings are within acceptable bounds. Original Web Forms documentation is at: https://docs.microsoft.com/en-us/dotnet/api/system.web.ui.webcontrols.rangevalidator?view=netframework-4.8

Blazor Features Supported

• MinimumValue and MaximumValue range boundaries
• Data type validation: String, Integer, Double, Date, Currency
• CultureInvariantValues for culture-independent comparisons
• ErrorMessage display when validation fails
• Integration with EditForm validation

WebForms Features Not Supported

• Display property (Static, Dynamic, None) - Blazor handles rendering differently
• SetFocusOnError - Blazor has different focus management
• EnableClientScript - Blazor uses its own validation model

WebForms Syntax

<asp:RangeValidator
    ControlToValidate="string"
    CultureInvariantValues="True|False"
    Display="None|Static|Dynamic"
    EnableClientScript="True|False"
    Enabled="True|False"
    ErrorMessage="string"
    ForeColor="color name|#dddddd"
    ID="string"
    MaximumValue="string"
    MinimumValue="string"
    runat="server"
    SetFocusOnError="True|False"
    Text="string"
    Type="String|Integer|Double|Date|Currency"
    ValidationGroup="string"
    Visible="True|False"
/>

Blazor Syntax

<RangeValidator TValue="string"
    MinimumValue="1"
    MaximumValue="100"
    Type="ValidationDataType.Integer"
    ErrorMessage="Value must be between 1 and 100"
    @ref="myValidator" />

Usage Notes

The RangeValidator is a generic component that takes a type parameter TValue. It inherits from BaseCompareValidator which provides the core comparison logic.

Example: Validating a Numeric Range

<EditForm Model="@model">
    <InputNumber @bind-Value="model.Quantity" />
    <RangeValidator TValue="int"
        MinimumValue="1"
        MaximumValue="999"
        Type="ValidationDataType.Integer"
        ErrorMessage="Quantity must be between 1 and 999" />
</EditForm>

Example: Validating a Date Range

<EditForm Model="@model">
    <InputDate @bind-Value="model.BirthDate" />
    <RangeValidator TValue="DateTime"
        MinimumValue="1/1/1900"
        MaximumValue="12/31/2010"
        Type="ValidationDataType.Date"
        ErrorMessage="Birth date must be between 1900 and 2010" />
</EditForm>

Supported Data Types

Type	Description
String	Alphabetical string comparison
Integer	Whole number range validation
Double	Decimal number range validation
Date	Date range validation
Currency	Currency value range validation

Behavior Notes

• Empty or null values pass validation (use RequiredFieldValidator in combination if the field is required)
• Whitespace-only values pass validation
• Both MinimumValue and MaximumValue boundaries are inclusive