coolvalidator by Mike

<PackageReference Include="coolvalidator" Version="1.0.3" />

.NET API 11,264 bytes

formValidator

public static class formValidator

public static List<Errors> ValidateObject(this Form form, object entity)

public static List<TextBox> ValidateTextBox(this Form form, ValidateType type = 1, Action method = null, Func<TextBox, bool> predicate = null)