Common Dialog Control
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The Common Dialog Control provides a standard interface
for operations such as opening, saving, and printing files or selecting
colours and fonts using the Microsoft Windows dynamic link
library COMMDLG.DLL. The Control is visible on the form as an icon
at design-time but not at run-time. The icon cannot be resized on
the form and it's not possible to specify where the Dialog will
be displayed when opened. To use a Common Dialog Control,
add "Microsoft Common Dialog Control" from the
"Project", "Components" menu item. The
three-letter mnemonic for a Common Dialog Control is "cdl".
The Control's Methods are used to determine which dialog is displayed.
The ShowColor method is used to display the Colour
The Color property is used to determine which colour was selected.
picPallette.FillColor = cdlColour.Color
Alternatively, you may wish to break out the long number into
its "Red", "Green" and "Blue" parts.
|Dim Red As Long, Green As Long, Blue As
Red = cdlColour.Color And &HFF
Green = (cdlColour.Color \ &H100) And &HFF
Blue = cdlColour.Color \ &H10000
The ShowFont method is used to display a list of fonts
that are available. Before the ShowFont method can be displayed,
the Flags property must be set to one of the following constants
or a Message Box is displayed with a message of "There are
no fonts installed", and a run-time error occurs.
|' Set default values for Font
cdlFont.FontName = lblSurname.FontName
cdlFont.FontSize = lblSurname.FontSize
cdlFont.Flags = cdlCFScreenFonts
lblSurname.FontName = cdlFont.FontName
lblSurname.FontSize = cdlFont.FontSize
The ShowHelp method is used to display a Windows Help
File. You can write your own help files using the "Help
Workshop" and display them with the Common Dialog
Control's ShowHelp method. The HelpFile and HelpCommand
properties must be set in order for the Help file to be displayed.
Help files are compiled files that are run using Winhlp32.exe.
The Help Workshop that is part of the Visual Studio suite
can be used to create Help files. The topics are written as Rich
Text Format .rtf files. These are linked with other resources
such as bitmaps into a single help file. The Help Workshop
enables you to edit the project and contents files, and compile
and test the help files.
The contents file is an ASCII text file, extension .cnt,
that provides the instructions for the Contents tab in the Help
Topics dialog box, and directs WinHelp to display the keywords of
specified Help files on the Index and Find tabs. The contents file
specifies the Headings, Topics, and Commands.
Headings contain a group of related topics and other Headings and
is shown as a Book Icon. Topics display a topic of execute
a macro and is shown as a page icon. The Commands specify the name
of the default help file, title, the names of help files to be included
on the Find tab and the names of help files containing keywords
for KLink and ALink macros.
|cdlHelp.HelpFile = "c:\juicystudio\tutorial.hlp"
cdlHelp.HelpCommand = cdlHelpContents
The ShowOpen method is used to display the dialog to open files.
The FileName Property is used to determine the name of the
file the user selected.
The Filter Property is used to determine the types of file
to be shown. A Pipe symbol, |, is used to separate the description
|cdlOpen.Filter = "Text (*.txt)|*.txt"
Further filters may be specified on the same line separated by
the Pipe symbol.
The following example uses a Common Dialog Control to
allow either Text or Picture files to be selected.
|Dim pattern As String
pattern = "Text (*.txt)|*.txt"
pattern = pattern & "|Pictures (*.bmp;*.gif;*.jpg)"
pattern = pattern & "|*.bmp;*.gif;*.jpg"
cdlOpen.Filter = pattern
picViewer.Picture = LoadPicture(cdlOpen.FileName)
The ShowPrinter method is used to display the dialog
to open files.
The following example uses the ShowPrinter method
with the Printer object to set the number of copies and page orientation.
Printer.Copies = cdlPrinter.Copies
Printer.Orientation = cdlPrinter.Orientation
The ShowSave method looks exactly the same as the ShowOpen
method, except the default title is "Save As"
rather than "Open".
The following example uses the ShowSave method
with the FSO to write the URL http://www.juicystudio.com to a text
file specified by the user.
|Dim fso As New FileSystemObject
Dim txtStream As TextStream
Set txtStream = fso.CreateTextFile(cdlSave.fileName, True)
Set txtStream = Nothing
Set fso = Nothing
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