# Differences from the .NET 1.x Version

This topic enlists the changes in this version that are not compatible with the 1.x versions.

## Content



Please note that some changes in this version are not compatible with the 1.x versions and may require (minimal) changes to the source code.

Changes from the .NET 1.x version include the following:

*   C1Input 2.x does not reference or need the C1Common assembly.
*   Flag properties, such as **FormatInfo**, **MaskInfo**, **PreValidatation**, and **PostValidation**, do not show the Inherit flags at design time since those flags are set automatically.
*   Most complex properties can now be reset to the default value in the designer.
*   The **CopyWithLiterals** property was removed from [C1TextBox](/componentone/api/win/online-input/dotnet-framework-api/C1.Win.C1Input.4.8/C1.Win.C1Input.C1TextBox.html) as it is duplicated in [MaskInfo](/componentone/api/win/online-input/dotnet-framework-api/C1.Win.C1Input.4.8/C1.Win.C1Input.MaskInfo.html).
*   The **AllowDbNull** property was removed from C1TextBox and is only available as a sub-property of the [PostValidation](/componentone/api/win/online-input/dotnet-framework-api/C1.Win.C1Input.4.8/C1.Win.C1Input.C1TextBox.PostValidation.html) property.
*   [C1DropDownControl](/componentone/api/win/online-input/dotnet-framework-api/C1.Win.C1Input.4.8/C1.Win.C1Input.C1DropDownControl.html) now allows the option to specify custom images for its buttons via the new [ButtonImages](/componentone/api/win/online-input/dotnet-framework-api/C1.Win.C1Input.4.8/C1.Win.C1Input.ButtonImages.html) Properties.