Required Field Validator

Write something Name is required. Not a 5 digit number. Not a 5 digit number with 0-3.
Bold Bullet List with HeaderText
Lime List
Italic Single Paragraph
ShowMessageBox (Migration Compatibility)

The ShowMessageBox property is accepted for migration compatibility with Web Forms <asp:ValidationSummary ShowMessageBox="true">. In Blazor, validation messages are displayed inline.

Code:

<RequiredFieldValidator Type="string" ControlRef="@Name" Text="Name is required." ErrorMessage="Name is required but in summary!" />
<RegularExpressionValidator ValidationExpression="^[0-9]{5}$" ControlRef="@Name" Text="Not a 5 digit number." />
<AspNetValidationSummary Font_Bold="true" DisplayMode="BulletList" HeaderText="Please fix these errors:" />