Data exchange When GIS360 requires and external EXE to display it will first prepare two text files which pass data to the EXE. DataIn.dat – This is a UTF-8 encoded XML file which contains the values for all fields in the current record for the current database. ExtInfo.txt – This file is used to pass information about access dates/times, and the current GPS position and quality In the examples, these files are loaded and interpreted by the “LoadDataFromGIS360” method. . The example code places the “ExtInfo” data in an “ExtInfo” object. Once the user has updated the fields and clicked OK in the external EXE Form, the EXE should create a file called “DataOut.dat” in the same folder as itself. “DataOut.dat” should be a UTF-8 encoded XML file containing the data for the fields edited in the EXE. For the examples, this file would contain data similar to this… PointID 123 textbox DataIndex 7639 textbox Once the output data is saved, the EXE should send a “SlaveToMasterCodes.OK” message to GIS360 and then hide itself. If the user Cancels the form, then the EXE does not need to prepare a “DataOut.dat” file, it just needs to send a “SlaveToMasterCodes.Cancel” message to GIS360 and then hide itself. Examples of these operations can be found in the “pictureBoxOK_Click” and “pictureBoxCancel_Click” methods in the examples. Managing external Databases In some applications the data to be maintained will be in an external database rather than from GIS360’s internal data structure. The external database could be large and performance would suffer if this had to be loaded every time the external EXE form was displayed. This is reason why the external EXE should operate by simply hiding itself and staying resident in memory when it is not displayed. Handling external databases will depend on the format of the database so is not covered in the example programmes. There are two skeleton methods in the examples to indicate where the external database should be loaded and saved. These are the “LoadExternalDatabase()” and “SaveExternalDatabase()” methods. GIS & GNSS map creation tools 153

Carlson gis360 v4 manual