This topic provides technical details on embedding license information into your applications. This is a special resource that must be present in every application that uses the data provider.

Note   License information discussed in this topic is not same thing as license for using dotConnect Universal. License purchased on our site allows you (Single license) or your company (Site license) to use dotConnect Universal. For information on how to purchase license for using dotConnect Universal please refer to topic Ordering.

The article consists of following sections:

• General Information
• Adding License Automatically
• Adding License Manually
• Class Libraries Support
• Licensing ASP.NET Applications
• Licensing Compact Framework Projects
• DbProviderFactory Notes
• Compiling License Manually
• Licensing Mono Projects
• Troubleshooting

General Information

dotConnect Universal uses .NET component licensing. To build an application dotConnect Universal requires valid license. If no license is available, dotConnect Universal does not work.

License information is a specially formed embedded resource. Usually you do not have to care about embedding the license in your application. When you install the Data Provider, the system is configured so that licensing is done transparently.

Note that end-users of your software do not require any additional license.

dotConnect Universal includes License Wizard that helps you configure license information. The wizard analyzes the current project, informs you about problems found, and performs some actions needed to fix the problems.

To invoke the wizard choose Tools | Universal | License Information menu item. Then click on Fix buttons in the dialog and follow the wizard's instructions. In most cases this is enough to configure .NET component licensing.

The following table helps get started quickly with dotConnect Universal licensing. Find your type of application and follow links to corresponding sections of the article.

Diagram	Explanation
	This is general case of licensed .NET Framework application. Whatever the type of application you develop, read carefully sections Adding License Automatically and Adding License Manually.
	These two diagrams show how you can use dotConnect Universal through a class library. In addition to Adding License Automatically and Adding License Manually please read section Class Libraries Support.
	These are two modes of accessing dotConnect Universal within ASP.NET application. In addition to Adding License Automatically and Adding License Manually please read section Licensing ASP.NET Applications.
	Some applications that have no licensing information embedded, and use DbProviderFactory to operate dotConnect Universal, require the product installed on the computer. Refer to section DbProviderFactory Notes for more information.

Adding License Automatically

License is automatically added to project when you drop a UniConnection component from Toolbox onto a form designer.

Under .NET Compact Framework, in the moment of compilation license information is automatically added if the dotConnect Universal addin for Visual Studio is running.

Adding License Manually

You may be required to manually add license. It is necessary for console applications, class libraries and existing projects initially built with dotConnect Universal 3.00. In this case perform the following steps:

• Create a file named licenses.licx, if this file does not exist yet.
• Open the file with a text editor and place this line inside:
  Devart.Data.Universal.UniConnection, Devart.Data.Universal
• Save the file and add it to your project.
• Make sure it is embedded as a resource.

If IDE fails to compile the license automatically you can do it yourself as described in section Compiling License Manually.

Note: if you use other Devart products (dotConnect for Oracle, dotConnect for MySQL, dotConnect for PostgreSQL, dotConnect for SQLite) as underlying data provider, you have to include license information for this data provider as well.

Note: Professional edition of dotConnect Universal is shipped with built-in data providers for Oracle, MySQL, SQLite, and PostgreSQL servers. If you use the bundled data providers you don't need any additional license information.

Class Libraries Support

In case where it is impossible to put the license information straight to executable file, dotConnect Universal allows to create class libraries that can be used with certain executable files. To do this perform the following steps:

1. Create and setup file named licenses.licx as described above.
2. Create a text file named licenses.config and place it next to licenses.licx.
3. In this file enumerate names of executable files that will work with the library, every file name on separate line, for example:
   
   MyApplication.exe
   MyAnotherApp.exe
   ExtraTool.exe

You do not have to add the file licenses.config to project.

Licensing Web Projects

There are two types of web projects depending on the type of licensing.

1. First, Web Application Project (Web Forms, MVC, Web API, etc.) are compiled entirely, so that web server does not perform any compilation on demand. In this case licensing web applications is same as licensing common Class Library applications.
2. Second, there are Web Site Projects, when source files are uploaded to server, where they are compiled on user request. In this case you should deploy a special assembly App_Licenses.dll to the Bin directory of your site for the Web Site projects. To create this assembly, right-click the licenses.licx file in the Solution Explorer view and then click Build Runtime Licenses. The required assembly will be created automatically. Note that the corresponding shortcut menu command is available when the licenses.licx file is located in the root folder of the site.

Licensing Compact Framework Projects

For .NET Compact Framework the Visual Studio addin automatically embeds all required information into every assembly that uses Devart.Data.Universal.dll library. Class libraries are supported automatically.

If the license fails to be added to project, you can add and compile it manually. Note that there is no license compiler from Microsoft for .NET Compact Framework. You can request the compiler from Devart support team.

There is a known problem with the .NET Compact Framework. A "License not found" exception can be thrown by UniDataAdapter.Fill method in case when UniConnection had never been opened. To avoid the problem just open (or open and close) any connection before calling the UniDataAdapter.Fill method.

DbProviderFactory Notes

Applications that call dotConnect Universal through DbProviderFactory require registration in DbProviderFactory. This registration can be performed either by launching installer of dotConnect Universal with Minimal install type (the licenses.licx file is not required in this case), or manually as it is described in the Deployment topic.

Compiling License Manually

The license resource cannot be compiled automatically when your project does not have reference to Devart.Data.Universal.dll or dotConnect Universal is not installed on your build server. This section describes how to compile the required resource manually.

Generate licensing resource file using following command line:
"%Compiler Path%\lc.exe" /target:MyApplication.exe /complist:licenses.licx /i:"%Assembly Path%\Devart.Data.Universal.dll"
Where

• %Compiler Path% is a path to appropriate lc.exe file (for example, C:\Program Files\Microsoft Visual Studio 8\SDK\v2.0\Bin in case of .NET Framework 2.0);
• MyApplication.exe is name of your target executable file;
• licenses.licx is a text file described earlier in this topic;
• %Assembly Path% is location of Devart.Data.Universal.dll assembly

Substitute these arguments with actual values. If license compiler fails with error, try adding full assembly specification to licenses.licx file, for example:
Devart.Data.Universal.UniConnection, Devart.Data.Universal, Version=3.0.1.0, Culture=neutral, PublicKeyToken=09af7300eec23701

License compiler will generate 'MyApplication.exe.licenses' resource file. You should add this file to your project as an embedded resource. Note that you should not add licenses.licx to the project because the *.licenses file already includes all the necessary license information. If the default namespace of your project is not an empty string it must be the same as target assembly name (in this case - 'MyApplication'). IDE adds the default namespace to resource name when building the application, so you have to rename 'MyApplication.exe.licenses' to 'exe.licenses' before adding it to the project. If the default namespace of your project is not set (is empty string) you do not have to rename the resource file before adding it to the project.

Licensing Mono Projects

Since automatic license generation and embedding is not possible with Mono you have to add and compile license manually as described above.

Troubleshooting

When something's wrong with license information you get one of the following exceptions on connecting to server:

Exception text	Possible reasons and what to do
License not found...	This generally indicates that license information could not be found, or you try to apply it in some way that does not suit the kind of application. For example: File licenses.licx, required for dotConnect Universal to function properly, could not be found. File licenses.licx is not added as embedded resource. File App_Licenses.dll not found in ASP.NET 2.0 applications. To fix the problem determine type of your application and read corresponding section in this topic. This exception can be thrown by UniDataAdapter.Fill method under .NET Compact Framework, in case when UniConnection had never been opened. To avoid the problem just open (or open and close) any connection before calling the UniDataAdapter.Fill method.
License not valid...	This means that license information was found but it is incorrect. It usually happens in the following cases: The project was earlier compiled with old or trial version of data provider. File licenses.config used by a class library does not refer to launched executable. The App_Licenses.dll belongs to other application or needs to be recompiled. Something's wrong with the operating system or installation of dotConnect Universal. You are building your project on a computer with no dotConnect Universal installed (for example, it is not installed on your build server), and the compiled license resource is not added to the project. If you encounter one of these problems, do the following (the numbers of actions correspond to the numbers of the problems in the above list): Delete all files from the bin and obj folders and rebuild the project. Specify the executable in the licenses.config file. Rebuild App_Licenses.dll for the current application. Perform the following steps: uninstall dotConnect Universal; remove all Devart.* and policy.*.Devart.* files from the GAC; clear the Program Files\Devart\dotConnect and Program Files\Common Files\Devart\dotConnect folders; re-install dotConnect Universal. There are two ways to solve the problem: Install dotConnect Universal on the computer where you build your project. Compile the license resource (*.licx file) on a computer, where dotConnect Universal is installed, and then add the result file (*.licenses) to your project as an embedded resource. After this you can build your project on a computer with no dotConnect Universal installed. If this does not help, send a small compiled binary with sources to our support address, so we can investigate the problem in more details.
Sorry, your trial period has expired...	This exception indicates that you used trial version of dotConnect Universal, and the 30 days trial period is expired. To continue using dotConnect Universal register it or uninstall from your machine. You can also see this message if the application was compiled with registered version of dotConnect Universal, but deployed with trial assembly Devart.Data.Universal.dll. If this is the case, replace old files with latest assemblies.