1. What are the Windows Common Dialogs and how do I use them?
Microsoft have made available some predefined dialogs (windows) for common tasks. These can be
used without needing further programming:
- OpenFileDialog() - Displays dialog to open a file.
- OpenFolderDialog() - Displays dialog to open a folder.
- SaveAsDialog() - Displays dialog to save a file with a new name.
- PrintDialog() - Displays dialog to print a file.
- FontDialog() - Displays dialog to choose a font.
- ColourDialog() - Displays dialog to choose pretty colours.
To use these dialogs just call the function. The dialog is then loaded, shown and unloaded
automatically without further programming. Note that the open, save and print dialogs get the
information needed to carry out the command but do not actually do the reading, saving or printing
of files. Windows cannot carry out the actual tasks of saving, printing etc because it does not
have the data to save/print, nor does it know how to save/print it.
2. What other Common Dialogs are available?
This table shows all the common dialogs available to your programs. The table also includes
dialogs which are similar to the common dialogs, such as built-in modal windows like Msgbox,
and other dialogs like the Aboutdialog which are in separate add-on classes:
| Description |
Function name |
Details |
| About (program information) |
AboutDialog |
Display a modal dialog with some information about the program, and an optional logo. This
dialog is in the Commdlgs class, and Commdlgs must be included in the uses
clause to enable it. |
| Color selection |
ColorDialog / ColourDialog |
Display a modal dialog for selecting a color value - both UK English and American English
spellings are allowed. This dialog is in the System class and is included
automatically. |
| Find text |
FindDialog, FindNext |
Display a modal dialog with a field for entering a search string and options such as
case-sensitive searching. FindNext is a companion dialog that repeats the last search. These
dialogs are in the Commdlgs class, and Commdlgs must be included in the uses
clause to enable them. |
| Font selection |
FontDialog |
Display a modal dialog for choosing a font. You can choose the font name, the point size, and
the bold and italic state. This dialog is in the System class and is included
automatically. |
| Input some text |
InputBox |
Display a modal dialog with a single entry field for typing in some text. This dialog is in the
System class and is included automatically. |
| List of items |
ListBox |
Display a modal dialog with a list of items. One of the items can be selected and is returned
by the dialog. This dialog is in the System class and is included automatically. |
| Message display |
MsgBox |
Display a modal dialog with some text and one or more buttons. When the dialog is closed, you
can detect which button was pressed. This dialog is in the System class and is included
automatically. |
| Open one or more files |
OpenFileDialog |
Display a modal dialog with a list of the files currently in a folder. You can navigate to
different folders, and select one or more files using the dialog. This dialog is in the
System class and is included automatically. |
| Open one or more folders |
OpenFolderDialog |
Display a modal dialog with a list of folders. You can navigate to different folders and
different disk drives, and select a folder using the dialog. This dialog is in the System
class and is included automatically. |
| Print (confirm details of print-out) |
PrintDialog |
Display a modal dialog with details of the selected printer and options to allow the printer
and the number of copies to be changed. This dialog is in the System class and is included
automatically. |
| Printer Setup (confirm printer to use) |
PrinterSetupDialog |
Display a modal dialog with a list of all connected printers, and return the selected printer.
If you don't want the Printdialog to be able to change the printer, this provides an alternate way
of doing the same thing. This dialog is in the Commdlgs class, and Commdlgs must be
included in the uses clause to enable it. |
| Replace text |
ReplaceDialog |
Display a modal dialog with a field for entering a search string and a replacement string, and
other options such as case-sensitive searching and global replacements. This dialog is in the
Commdlgs class, and Commdlgs must be included in the uses clause to enable
it. |
| Save file |
SaveAsDialog |
Display a modal dialog with a filename, and allow the filename and the location of the file to
be changed. This dialog is in the System class and is included automatically. |
3. How do I use the Windows MessageBox function?
Instead of MessageBox use MsgBox which is very similar, but allows extra buttons
with customized text on them. There are several similar dialogs: MsgBox, InputBox and
ListBox. These are shown using a single function call, and they don't need any extra setup
work using the dialog editor or objects or properties.
4. How do I tell if the user pressed Cancel in a common dialog?
The common dialogs don't raise exceptions if the user pressed Cancel. Instead you can tell from
the parameters returned by the dialog. If the dialog is closed or cancelled it returns empty
strings instead of useful information.
5. How do I select more than one file using the
OpenFileDialog?
Use the OPENDLG_MULTI flag, and the returned list of selected files (one or more) will be
returned in a multi line string. Use the following code to get the returned files:
files <- Openfiledialog("Open files", OPENDLG_MULTI, "*.*")
for i from 1 to Strcount(files)
file <- Strline(files,i)
file <- StrRtrimCrLf(file)
// use file here
end for
The call to Openfiledialog allows one or more files to be selected. If the user chose any
files and did not click the Cancel button, Strcount(files) will be greater than or equal to
one. The for loop reads each line in the returned multi line string, removes the end of line
characters from each line and copies it to the file variable. At this point the file
variable contains each selected path name and is ready for use.
6. How do I choose a directory or a folder?
Use OpenFolderDialog. If the user presses OK when closing the dialog, the returned
directory name is guaranteed to exist.
|
to test this page.