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© 1999, by Que Education and Training, Appendix A, pages 769-776 of Introduction to Computer Programming with Visual Basic 6: A Problem-Solving Approach.

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Presentation on theme: "© 1999, by Que Education and Training, Appendix A, pages 769-776 of Introduction to Computer Programming with Visual Basic 6: A Problem-Solving Approach."— Presentation transcript:

1 © 1999, by Que Education and Training, Appendix A, pages of Introduction to Computer Programming with Visual Basic 6: A Problem-Solving Approach Adding Common Dialog Control n Not on standard Toolbox n To add this custom control, select Components from Project menu

2 © 1999, by Que Education and Training, Appendix A, pages of Introduction to Computer Programming with Visual Basic 6: A Problem-Solving Approach Common Dialog Control n Custom control that allows VB program to use dialog boxes provided with Windows ColorFileFontPrint n Hungarian notation: dlgNameOfControl n Size of dialog box is controlled by Windows and cannot be changed by program n Only one control is needed to access all standard dialog boxes by the form

3 © 1999, by Que Education and Training, Appendix A, pages of Introduction to Computer Programming with Visual Basic 6: A Problem-Solving Approach Control Color: Common Dialog n Place common dialog control on form (it remains invisible during execution) n To allow the user to control the color aspect of one or more objects, write an event procedure (e.g., mnuEditColor_Click) with the following logic 1)Assign defaults to dialog box: dlgName.Flags = cdlCCRGBInit ‘ initialize dialog box dlgName.Color = frmName.BackColor ‘ assign backcolor on form 2)Display the desired standard dialog box to user: Call dlgName.ShowColor 3)Apply information from dialog box selected by user to program: frmName.BackColor = dlgName.Color lblNumber.ForeColor = dlgName.Color

4 © 1999, by Que Education and Training, Appendix A, pages of Introduction to Computer Programming with Visual Basic 6: A Problem-Solving Approach Control Font: Common Dialog n Place common dialog control on form (it remains invisible during execution) n To allow the user to control the font aspect of one or more objects, write an event procedure (e.g., mnuEditFont_Click) with the following logic 1)Assign defaults to dialog box: dlgName.FontBold = lblNumber.Font.Bold dlgName.Flags = cdlCFScreenFonts ‘ install fonts to show in list box ‘ see below to include color, strikethru & underline on font dialog dlgName.Flags = cdlCFEffects Or cdlCFScreenFonts 2)Display the desired standard dialog box to user: Call dlgName.ShowFont 3)Apply information from dialog box as selected by user to program: lblNumber.Font.Name = dlgName.FontName lblNumber.Font.Bold = dlgName.FontBold lblNumber.Font.Italic = dlgName.FontItalic lblNumber.ForeColor = dlgName.Color

5 © 1999, by Que Education and Training, Appendix A, pages of Introduction to Computer Programming with Visual Basic 6: A Problem-Solving Approach Control File Access: Common Dialog n Place common dialog control on form (it remains invisible during execution) n Example: mnuOpenPicture_Click lets user pick image 1)Optional: adjust window parameters to better inform user: dlgCommon.Flags = cdlOFNFileMustExist ' file must exist flag dlgCommon.DefaultExt = ".gif" ' default extension.gif dlgCommon.Filter = ”Picture (*.gif)| *.gif" ' filter show these files ' customize the title bar of the dialog box dlgCommon.DialogTitle = "OPEN--Please select picture file” 2)Display the desired standard dialog box to user: Call dlgName.ShowOpen 3)To use information from dialog box selected by user: imgFlag.Picture = LoadPicture(dlgName.FileName)

6 © 1999, by Que Education and Training, Appendix A, pages of Introduction to Computer Programming with Visual Basic 6: A Problem-Solving Approach Updated Colorful Hello World

7 © 1999, by Que Education and Training, Appendix A, pages of Introduction to Computer Programming with Visual Basic 6: A Problem-Solving Approach Updated Colorful Hello World n Allowing the user to change background colors ' Purpose: The Color Palette appears with the current options shown as ' defaults. Any changes made by the user appear on the form. Private Sub mnuEditChangeBackColor_Click() dlgCommon.Flags = cdlCCRGBInit ' initialize dialog box dlgCommon.Color = frmMain.BackColor ' assign backcolor on form Call dlgCommon.ShowColor frmMain.BackColor = dlgCommon.Color fraLanguage.BackColor = dlgCommon.Color optEnglish.BackColor = dlgCommon.Color optSpanish.BackColor = dlgCommon.Color optHindi.BackColor = dlgCommon.Color End Sub

8 © 1999, by Que Education and Training, Appendix A, pages of Introduction to Computer Programming with Visual Basic 6: A Problem-Solving Approach Updated Colorful Hello World n Allowing the user to change font styles ' Purpose: The Font dialog appears with the current options shown as defaults. ' Any changes made by the user are reflected in the message label. Private Sub mnuEditChangeFont_Click() dlgCommon.FontName = lblMessage.Font.Name dlgCommon.FontBold = lblMessage.Font.Bold dlgCommon.FontItalic = lblMessage.Font.Italic dlgCommon.FontSize = lblMessage.Font.Size dlgCommon.Color = lblMessage.ForeColor dlgCommon.FontStrikethru = lblMessage.Font.Strikethrough dlgCommon.FontUnderline = lblMessage.Font.Underline dlgCommon.Flags = cdlCFScreenFonts ' install fonts to show in list box ' see below to include color, strikethru & underline on font dialog dlgCommon.Flags = cdlCFEffects Or cdlCFScreenFonts Call dlgCommon.ShowFont lblMessage.Font.Name = dlgCommon.FontName lblMessage.Font.Bold = dlgCommon.FontBold lblMessage.Font.Italic = dlgCommon.FontItalic lblMessage.Font.Size = dlgCommon.FontSize lblMessage.ForeColor = dlgCommon.Color lblMessage.Font.Strikethrough = dlgCommon.FontStrikethru lblMessage.Font.Underline = dlgCommon.FontUnderline End Sub

9 © 1999, by Que Education and Training, Appendix A, pages of Introduction to Computer Programming with Visual Basic 6: A Problem-Solving Approach Updated Colorful Hello World n Allow the user to view a different picture ' Purpose: The File open dialog appears to allow the user to select a new ' image for the form. Private Sub mnuFileChangePicture_Click() dlgCommon.Flags = cdlOFNFileMustExist ' file must exist flag dlgCommon.DefaultExt = ".gif" ' default extension.gif dlgCommon.Filter = "Picture (*.gif)| *.gif" ' filter show the files ' customize the title bar of the dialog box dlgCommon.DialogTitle = "OPEN--Please select new picture file” Call dlgCommon.ShowOpen imgFlag.Picture = LoadPicture(dlgCommon.FileName) End Sub

10 © 1999, by Que Education and Training, Appendix A, pages of Introduction to Computer Programming with Visual Basic 6: A Problem-Solving Approach Use Error Handler in Hello World n Make the Flags property assignment line a comment ' Purpose: The File open dialog appears to allow the user to select a new ' image for the form. Private Sub mnuFileChangePicture_Click() On Error GoTo ErrHandler ' dlgCommon.Flags = cdlOFNFileMustExist ' file must exist flag dlgCommon.DefaultExt = ".gif" ' default extension.gif dlgCommon.Filter = "Picture (*.gif)| *.gif" ' filter show the files ' customize the title bar of the dialog box dlgCommon.DialogTitle = "OPEN--Please select new picture file” Call dlgCommon.ShowOpen imgFlag.Picture = LoadPicture(dlgCommon.FileName) Exit Sub ErrHandler: Call MsgBox("Error #" & Err.Number & ": " & Err.Description, _ vbOKOnly + vbExclamation) End Sub


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