MDL has been a powerful development tool since MicroStation 4.0, and it dates back to the early 1990s. At that time, MDL was the abbreviation of MicroStation Development Language, which was an extended language of Bentley based on the C language, and the compiler and linker were provided by Bentley. The final program extension is  .ma, which is the abbreviation of the MicroStation Application. We call this development method PureMDL. You only need a source code editor to develop PureMDL, and other tools (compiler, linker, and debugger) are provided by Bentley.

As time went by, MDL was also advanced. Today MDL can be developed based on C++, so we can use Microsoft Visual Studio as a development tool to generate native code DLLs. At the same time, in order to retain some of the features of MDL (such as command tables, MDL-specific resources, etc.), we still need to generate a .ma file. We call this new MDL, NativeCode MDL, where the MDL is no longer MicroStation Development Language but MicroStation Development Library. Native code MDL enables you to write code using object-oriented programming, and also enables you to directly call any function that can be called in VC++.

Bentley released a brand new MicroStation CONNECT version (Mstn CE) software in August 2015, which has the following updates:

• 64-bit applications, make full use of memory space
• Brand new Ribbon interface
• Enhanced dynamic view-Drawing Boundary and Named Boundary
• Enhanced Explorer-Added Item, Resource, and Sheet Index pages
• Parametric Modeling-Parametric Modeling (replaces the original Feature Modeling and DDD)
• User-defined attributes-Item Types (replaces the original Tag and TagSet)
• Can directly publish and open .imodel
• New features-Labels, Reports, and Tables
• Loadable ContextCapture (formerly Acute3D) 3D models created from pictures*.3MX/*.3SM
• Latest technology Scalable Mesh: 3SM file format (3SM-Demo.dgn)
• Other: WorkSet, Help, Search Ribbon

From a development perspective, the changes in the Mstn CE MicroStation SDK are even greater. Almost all functions have been repackaged with C++ classes. We can almost no longer call the old C functions for programming. This is what we have been hoping for and finally achieved. But at the same time, because it is a new C ++ package, it also brings a lot of learning burden to our development. This article is intended to lead everyone to learn this new MDL C++ programming. Although most of the original C functions are still supported, it is highly recommended that new C++ classes be used for new application development. MicroStation CE Update 14 version is used at the time of this writing, so all future code will be written based on this version. When you read these articles, there may be newer versions released, so please follow the instructions in the latest version to make appropriate adjustments.

Installation Process:

To develop an MDL application under MicroStation CE, follow these steps to install the development environment:

1.Install Visual Studio
   During the installation process, you must choose to install VC ++ (the default installation may not have this option selected), and you must also choose to install the Windows 10 SDK components.
2. Install MicroStation CONNECT 
3. Install MicroStation CONNECT SDK 

     

If you do not already have the MicroStation software and its development kit (SDK), you need to join the Bentley Developer Network (BDN) to obtain them. For more information about joining BDN, please contact Bentley's BDN team (bdn@bentley.com).

Since MicroStation CE is a 64-bit program, it must be installed on 64-bit Windows. The default installation locations of MicroStation and its development kit are as follows:

• MicroStation directory: C:\Program Files\Bentley\MicroStation CONNECT Edition\MicroStation
• Configuration file (including workspace): C:\ProgramData\Bentley\MicroStation CONNECT Edition\Configuration
• SDK directory: C:\Program Files\Bentley\MicroStationCONNECTSDK

SDK Components:

The following describes the components of the SDK one by one:

• bin: This folder contains the executables needed to generate the final application and batch files to launch the development environment. The following execution program is mainly responsible for generating the resource part of the final application. The compilation and linking of C ++ code invoke cl.exe and link.exe in VS.
• Documentation: The development help documents are present in 'chm' format in this folder, from which we will use MicroStationApi.chm (MDL C++ help documentation). The other help documents are for developing MSTN applications with C#.
  • Readme: SDK Readme is in web format. Double-click the index.html file under it to open it in your browser. It contains the changes of each SDK version, how to install the SDK, and precautions for developers, etc.
  • Migration tools: Some upgrade guides for upgrading V8i to CE.
• examples: This folder contains a lot of MDL C++ or C # sample code. Some of them are old and some are newly written (for example, when the command writing tool is used, if it is a function of the mdlState_xxx class that is called, it must be an old example. The one derived from the DgnTool class should be new of). Following the new examples are recommended.
• include: This folder contains C++ header files
• library: This folder contains C ++ library files
• MigrationTools: Some tools to help you migrate from V8i code to CE code. Mainly through the Python program to map some keywords. You can manually modify the contents of the file 0811to1000Published.remap to extend this mapping library.
• mki: Contains make file header files (make include). Some system files that serve the mke files.
• eula.pdf: Bentley Software End User License Agreement. Numerous legal provisions state which acts are prohibited by law.
• MicroStationDeveloperShell.bat: A batch file that launches the development environment.

Next: [[Building a simple MDL Application]]