【正文】 for example, what would be CreateCircle() is just Circle() ?? Functions that would begin with Convert or Compute have that dropped as well。 for example, what would be ConvertRealToInt() is just RealToInt() ?? Boolean functions take the form of a declaration rather than a mand, such as CoordInMap() In addition, the following abbreviations are used: Term Abbreviation Integer Int Geography Geo Minimum Min Maximum Max Database DB (for geographic files only) Dialog Box Dbox Description Desc Information Info For more information, see... Passing Null to Represent a Default Value 4 Identifying Maps, Layers, and Selection Sets Identifying Views and Sets Identifying Fonts Identifying Windows Identifying Fields Using Boolean Values Using Options Arrays Passing Null to Represent a Default Value Many GISDK functions interpret a null value for an argument to indicate that a default value should be used. For example, most GISDK functions that take a map name as an argument interpret null to mean the current map. The same applies to GISDK functions that take an editor name, a layout name, or a layer name. GISDK functions that affect display characteristics interpret null to mean no change. For example, calling SetIconColor() on a selection set with a null value for the color indicates that the color of features in the set should not be changed from the default for the layer. Identifying Maps, Layers, and Selection Sets GISDK functions that change layer styles accept several types of strings that identify the map, layer, and selection set to be modified. These strings use a vertical bar to separate the different parts of the string. Any of the following is acceptable: Syntax... What it means... mapname|layername|setname Modify the style of features in the named map, layer, and selection set layername|setname Modify the style of features in the named layer and selection set in the current map setname Modify the style of features in the named selection set for the current layer in the current map layername| Modify the style of features in the named layer in the current map null Modify the style of features in the current layer in the current map A similar set of options is available for setting the style of a theme class. The following are acceptable: 5 Syntax... What it means... layername|themename|class_id Modify the style of features in the named layer, theme and class themename|class_id Modify the style of features in the named theme and class on the current layer Some display characteristics affect an entire layer and cannot be used on individual selection sets. For example, SetLayerVisibility() determines whether a layer is drawn in a map or not. For layerwide display GISDK functions, you specify the map and layer you are changing in one of three ways: Syntax... What it means... mapname|layername Modify the named layer in the named map layername Modify the named layer in the current map null Modify the current layer in the current map Identifying Views and Sets Many GISDK functions work with views and sets. For example, GetFirstRecord() gets the first record in a particular set in a particular view. You specify which view and set you are using with a string that can have one of four formats: Syntax... What 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