Computer-Aided Process Planning (CAPP) designs the processing methods and manufacturing processes of a product based on information provided by the product design. It serves as a bridge and link between Computer-Aided Design (CAD) and Computer-Aided Manufacturing (CAM) and is a crucial component of CIMS (Computer Integrated Manufacturing System). Since its emergence in the late 1960s, CAPP has evolved over 30 years, developing various systems with different design methodologies: retrieval-based systems, derivative systems, generative systems, and hybrid systems. This paper discusses a screw pump CAPP system that primarily employs two process customization modes: retrieval-based and interactive card-filling. The retrieval-based system mainly enables the retrieval and management of mature process specifications, as well as the querying and accessing of existing process documents, suitable for manufacturing repetitive parts, common parts, or standardized products produced in rotation. This paper primarily introduces the research and development process of the interactive card-filling module. 1. Principles and Characteristics of the Interactive Card-Filling Module The design philosophy of the screw pump CAPP system is based on practicality and takes into account the actual application of enterprises. Its interactive card-filling module is designed to overcome the shortcomings of the retrieval-based module in terms of inheritance and flexibility. This allows process designers to flexibly input and edit process information based on their rich experience and the current situation of the enterprise. It also allows for selective loading of relevant resources based on the resource information database and enables appropriate modifications as needed. Interactive refers to the system automatically loading relevant resources from the database based on the user's selected fields when filling in information, allowing the user to choose and use them. 2 Key Technologies for Interactive Card-Filling Module Development 2.1 Establishment of Process Card Templates For most enterprises, their process cards have a certain fixed format (generally, process cards can be divided into three parts according to information content and layout: card header information, main card content information, and table footer information). Therefore, the process card template can be established using the graphics operation functions in VC++ (mainly using MFC). Using the CDC class (simply put, the CDC class mainly completes the drawing function and environment establishment), the card template is established in the OnDraw() function. The effect after running is shown in Figure 1. 2.2 Interactive Entry of Process Information 2.2.1 Automatic Loading of Overall Part Information During Initialization After the CAD personnel complete and submit the design of the product parts, the CAPP personnel obtain necessary overall information about the parts (such as part name, drawing number, material, etc.) from the PDM database. When the relevant card template is opened, the system automatically connects to the server's database, loads this information, and displays it in the card. The result after running is shown in Figure 2. 2.2.2 Loading of Process Drawings The system connects to the server via FTP programming, downloads the process drawings of relevant parts to the designated port on the local machine, and then loads the process drawings into the process card and displays them. This system establishes an FTP connection with the server and downloads relevant information, requiring the use of functions from the CInternet Session and CFtp Connection classes. Specific code can be found in relevant books and will not be detailed here. The display of process drawings mainly relies on the built-in browser and the 4ntoVueX control. The result after running is shown in Figure 3. 2.2.3 Interactive Input of Text Information This CAPP system mainly uses two methods to achieve interactive input of text information. 1) Input of text information based on resource tree. This is mainly based on the characteristics of card information content being divided into 3 parts (header information, main card content information, and tail information). The specific implementation process is as follows: (1) Input of card header and tail information. This is achieved by dynamically creating a derived class CmyRichEdit based on CrichEditCtrl in each fill-in item space. The structure of the class is as follows: The specific implementation steps are: First, calculate the vertex coordinates of each fill-in item space and store them in two static two-dimensional arrays. Then, in the processing function of the WM_RBUTTONDOWN message, determine the position based on the coordinates of the right mouse click point and dynamically create an edit box control to realize information input. Some code segments are excerpted below: (2) Input of main card content information. In addition to inputting information using the same methods as the card header and tail, given the large amount and high level of specialization of information in the main card content section, which is suitable for database construction, an option has been added to retrieve and input information by accessing database resources. The specific method is as follows: first, right-click to select the blank space for the form (same as inputting information in the card header and tail). The left working window determines the required content item based on the coordinates of the mouse click point, loads the resource tree from the database, and then double-clicks the node on the resource tree loaded in the left working window. The content is automatically loaded onto the right process card. The effect after running is shown in Figure 4. 2) The information input method based on the editing dialog box is similar in function to the first method, but the implementation technology is different. The idea is to treat the information to be filled in as a graphic. When a blank item in the table is clicked with the left mouse button, the information is inserted at the click point. This can be done by selecting the item (represented by adding small solid rectangles to the edges of the selected area, see Figure 5) and moving it to the appropriate position. MFCE; has encapsulated an OLE class CrectTracker that can implement this function, which was directly adopted. This saves a lot of code and improves the program's running efficiency. 3. Implementation of the Interactive Card-Filling Module The development environment for the interactive card-filling module is VC++ 6.0, and the database used is MS SQL SERVER2000. The running effect is shown in Figure 6. 4. Conclusion Through the above introduction, we have learned the specific details and methods of developing an interactive card-filling module in a screw pump LAPP system using the object-oriented development tool VC++. The research and development of this module has certain practical value. Further functional improvements and enhancements will undoubtedly significantly improve the efficiency of process customization in actual production, saving substantial manpower and resources. Its application prospects are promising.