Common Dialog Control

Using the Open/Save Dialog

You can use the open dialog to allow the user to select a file, which your application can then open, or analyse etc. Below are the most common parameters you will need to set before displaying the Open Dialog Box.

Parameter Changes...
DialogTitle the Title displayed in the Dialog Box
Filter the File Types displayed in the file type list.
FilterIndex the default file type
Flags custom settings such as hide read-only files
CancelError whether an error occurs when the dialog box is cancelled.

The following code displays an open Dialog, with read-only files hidden. The extension list is set to allow Word Documents (*.doc) and Excel Spreadsheets (*.xls). The dialog will not allow you to select files that do not exist.

' Sets the Dialog Title to Open File
CommonDialog1.DialogTitle = "Open File"

' Sets the File List box to Word documents and Excel documents
CommonDialog1.Filter = "Word Documents (*.doc)|*.doc|Excel Spreadsheets (*.xls)|*.xls"

' Set the default files type to Word Documents
CommonDialog1.FilterIndex = 1

' Sets the flags - File must exist and Hide Read only
CommonDialog1.Flags = cdlOFNFileMustExist + cdlOFNHideReadOnly

' Set dialog box so an error occurs if the dialogbox is cancelled
CommonDialog1.CancelError = True

' Enables error handling to catch cancel error
On Error Resume Next
' display the dialog box
CommonDialog1.ShowOpen
If Err Then
    ' This code runs if the dialog was cancelled
    Msgbox "Dialog Cancelled"
    Exit Sub
End If
' Displays a message box.
Msgbox "You selected " & CommonDialog1.FileName

The Filter property is a string using the following format:

"FileTypeText1 |FileTypeExtension1 | FileTypeText2 | FileTypeExtension2"

The FileName property stores the selected file's path and name. The FileTitle property stores just the filename, you could use this to set a dialogbox's title:

Form1.Caption = "Text From : " & CommonDialog1.FileTitle

The following code displays an save Dialog. The extension list is set to allow Text File (*.txt) and All Files (*.*). It hides readonly files, prompts if you want to overwrite the existinf files, and only allows the file to be saved in a folder that already exists

' Sets the Dialog Title to Save File
CommonDialog1.DialogTitle = "Save File"

' Sets the File List box to Text File and All Files
CommonDialog1.Filter = "Text File (*.txt)|*."|AllFiles (*.*)|*.*"

' Set the default files type to Text File
CommonDialog1.FilterIndex = 1

' Sets the flags - Hide Read only, prompt to overwrite, and path must exist
CommonDialog1.Flags = cdlOFNHideReadOnly + cdlOFNOverwritePrompt _
+ cdlOFNPathMustExist

' Set dialog box so an error occurs if the dialogbox is cancelled
CommonDialog1.CancelError = True

' Enables error handling to catch cancel error
On Error Resume Next
' display the dialog box
CommonDialog1.ShowSave
If Err Then
    ' This code runs if the dialog was cancelled
    Msgbox "Dialog Cancelled"
    Exit Sub
End If

' Displays a message box.
Msgbox "You saved the files as  " & CommonDialog1.FileName

If you just want to display the open and save dialogs, what's the point of having a control with extra code you don't need? VB Web has the solution! Take a look at our Open/Save Dlg Control (with multi-file select support)

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