地理信息系统开发工具gisdk使用手册英文版第二部分calling_gisdk_functions

地理信息系统开发工具gisdk使用手册英文版第二部分calling_gisdk_functions内容摘要：

t it means... viewname|setname The named view and selection set setname The named selection set in the current view viewname| All records in the named view null All records in the current view Identifying Fonts Some GISDK functions require a font as an argument. In Caliper Script, a font specification is a string of the form: font_family_name|font_size font_family_name|Bold|font_size font_family_name|Italic|font_size font_family_name|Bold|Italic|font_size 6 Font sizes are expressed in points and can be real numbers, as in Times New Roman|Bold|. Font family names must exactly match the names returned by GetFontNames(). Identifying Windows When you call a GISDK function that can be used on all types of windows (., MinimizeWindow()), you must specify the window type as well as the window name, as in Map|My First Map or Editor|Sales Data. To use one of these GISDK functions with the TransCAD program window, call the GISDK function with Frame| as the argument (., MaximizeWindow(Frame|)). Identifying Fields As described in more detail in Tables and Views, GISDK uses both field names and field specs (specifications) to identify fields in a view. Some GISDK functions require field names, while others require field specs. In general, GISDK functions that operate on a single view (., GetFirstRecord()) take field names. GISDK functions that operate on a layer (., CreateTheme()) or on any view (., JoinViews()) take field specs. Refer to the documentation of an individual GISDK function to determine whether it takes field names or field specs. Using Boolean Values Many GISDK functions take boolean values (True or False) as arguments. Others return boolean values. When passing a boolean value to a GISDK function, either as a parameter or as the value of an option, pass a string containing the word True or False. In general, a GISDK function that returns a boolean value returns a string, either True or False, but there are some GISDK functions that return a different value, such as On or Off. Refer to the documentation for an individual GISDK function to determine its possible return values. Using Options Arrays Many GISDK functions take an array of options as a parameter. Each element in an options array is an array of two (or more) elements. The first element in each subarray is a string specifying the 7 name of the option. The second (and subsequent) elements of a subarray give the values for the option. For example, the following options array contains two options (Layer Name and Label) and their associated values: options_array = { {Layer Name, Counties} {Label, Counties of the Northeast} } You can use a dot notation to get, set, add, and remove options in options arrays. For more information, see Options Arrays and Dot Notation in Arrays. If you don39。 t need to pass any options to a GISDK function, you can pass null for the options array. Some GISDK functions also return options arrays. In general, you should not rely on the order in which options appear in a returned options array. Instead, to locate specific options within an options array, use the GISDK functions: GISDK Function Summary FindOption() Finds a particular option and its setting in an array of namevalue pairs FindOptionValue() Finds the value of a particular option in an options array In addition, some GISDK functions, like AddAnnotation() and GetAnnotation() accept or return information in the same format as an options array. You can use these same GISDK functions to manipulate these arrays. 2 Using GISDK Functions This section contains overviews of how you use GISDK functions to work with windows, maps, layers, editors, tables, and views, well as overviews GISDK functions for geographic data and analysis, works, routes systems, matrices, and other tasks. Also addressed are the key differences between the terminology used in TransCAD and the terminology used in GISDK. For more information, see... Windows Maps Geographic Data and Analysis Tables and Views Networks Route Systems 8 Matrices Other GISDK Functions Windows GISDK lets you create, manipulate, and close windows of five different types. You can control the location, size, and other settings for each window, save the contents of a window to a file, or open a file and create a window from its contents. You can also attach menus and toolbars to each and every window, and create macros that run automatically either when a user clicks in a window to activate it, or when a user closes the window. These capabilities let you separately customize the interface for each window in your application. The Standard Interface, however, has only one menu system for all windows, and only one toolbar for each window type. GISDK supports five types of windows: maps, editors (including dataviews), figures, layouts, and a special type of window called the frame. The frame is the TransCAD program window as it appears when no maps, editors, figures, or layouts are open. Every map, editor, figure, and layout has a name that distinguishes it from all other windows of the same type. For example, your application could have six different windows as shown in the table: Window Type Name 1 Map US Streets 2 Map States 3 Map US Streets:1 4 Editor US Streets 5 Editor State Data 6 Layout Untitled No two maps, editors, figures, or layouts can have the same name, although as indicated in the above example, a window of one type can have the same name as a window of another type. The windows in GISDK are also identified by name, where the window name is of the form window type|window name. For example, Map|US Streets, Editor|State Data, and Layout|Untitled are all valid window names in the abo。