Most applications define dialog templates in resource files rather than constructing template data structures in memory at run time. The dialog resource file defines the size and style of the dialog-window frame and specifies each dialog item.

The dimensions and position of each dialog item are specified in dialog coordinates, which are based on the size of the system font. A horizontal unit is one-fourth the average width of the characters in the system font; a vertical unit is one-eighth the average height of the characters in the system font. The origin of the dialog template is the lower-left corner of the dialog window. The operating system provides the WinMapDlgPoints function for converting dialog coordinates into window coordinates.