Leccion 10.3 - Data Report Con Codigo

8/2/2019 Leccion 10.3 - Data Report Con Codigo

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[VISUAL BASIC CON BASE DE DATOS] IDSYSTEMS 2012

LECCION 10.3 MS DataReport para ser desplegado, impreso o

exportado usando Codigo

Problem

I need to create an application that enables the user to choose the output method for the report. Iwould like the user to be able to choose whether the report is previewed to the screen, printed to the

printer, or exported to a file.

Technique

The data report has various methods defined to output a report. By using these methods, the

programmer can determine the output method forthe report. This How-To will demonstrate the ways inwhich the application can enable the user to choose the output method for the report.

The PrintReportmethod will be used to print the report directly to the Printer. This method can

be set to print directly to theprinter without any user intervention, or the method can be used to display adialog box to enable the user to select the print range and the number of copies to beprinted.

The ExportReportmethod will be used to generate a file of the report data. This method can beset to generate the file without any userintervention or a dialog can be displayed so the user can select the file

type and the page range.

The Showmethod will be used to display a print preview window of the report. This method is the

same used to display any other

Visual Basic form.

Steps

Open and run the OutputType.vbp project. This project enables the user to display, print, or exportthe report. When printing or exporting a report, the user can select the page range to be used. This is usefulin large reports.

1. Start Visual Basic and choose a new Data Project. Have the Data Environment point to the

BIBLO.MDB database.

2. Layout the form as in Figure 9.8 and set the properties of the objects as in Table 9.9.

Leccion 10.3 DataReport con codigo Pgina 1


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Figure 9.8. Arrangement of formfrmOutPut.frm.

Table 9.9. rptFunction control functions description.

OBJECT Property Setting

Form Name frmOutPut

Caption Data Report Output

Frame Name frExport

Caption Export Options

CheckBox Name chkExport

Caption Show Export Dialog

TextBox Name txtStartPageEx

TextBox Name txtPrintToEx

ComboBox Name cbExportType

Label Name lbExportType

Caption Export Type

Label Name lbStartPageEx

Caption Start Page:

Label Name lbPrintToEx

Caption Print to:

CommonDialog Name CD

Frame Name frPrint

Caption Print Options

TextBox Name txtPrintTo

TextBox Name txtStartPage

CheckBox Name chkShowDialog

Caption Show Print Dialog

Label Name lbPrintTo

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Caption Print To:

Label Name lbStart

Caption Start Page:

CommandButton Name cmdExit

Caption Exitr

CommandButton Name cmdExport

Caption Export

CommandButton Name cmdPrint

Caption Print

CommandButton Name cmdPreview

Caption Preview

3. Add the following code in the Loadevent of the Form:

Private Sub Form_Load()

cbExportType.AddItem "1 - HTML"

cbExportType.AddItem "2 - Text"

cbExportType.AddItem "3 - Unicode HTML"

cbExportType.AddItem "4 - Unicode Text" cbExportType.ListIndex = 0End Sub

This procedure will add the export types to the list box so the user can choose the format in which the report will

be exported.

4. Add the following code to the Clickevent of the cmdPreviewbutton:

Private Sub cmdPreview_Click()DataReport1.StartUpPosition = 0DataReport1.WindowState = 2

DataReport1.Show

End Sub

This procedure will maximize the size of the report windows to the full screen, then display the report.

5. Add the following code to the Click event of the cmdPrint button:

Private Sub cmdPrint_Click()



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Dim fReturn As Long

If txtStartPage.Text Or txtPrintTo.Text Then

If IsNumeric( txtStartPage.Text) = False Or :

IsNumeric( txtPrintTo.Text) = False Then

MsgBox The start or end pages to print is invalid., 64

Exit Sub

End If

End If

If txtStartPage.Text = And txtPrintTo.Text = Then

fReturn = DataReport1.PrintReport( chkShowDialog.Value * -1,

rptRangeAllPages)

Else

fReturn = DataReport1.PrintReport( chkShowDialog.Value * -1,

txtStartPage.Text, _

txtPrintTo.Text)

End IfIf fReturn = 2 Then

MsgBox Print Job Sent to Printer

Else

MsgBox Print Job Cancelled

End If

End Sub

This procedure prints the report to the printer. There are three variables that can be passed to the

PrintReportmethod. The first value is a Boolean value that determines if the Print dialog box isdisplayed. The second determines if all the pages are to be printed. If the second value is not set torptRangeAllPages, then a third value can be used to determine the range of pages that will beprinted.

6. Add the following code to the click event of the cmdExport button:

Private Sub cmdExport_Click()

Dim Overwrite As Boolean

If txtStartPageEx.Text "" Or txtPrintToEx.Text "" Then

If IsNumeric(txtStartPageEx.Text) = False OrIsNumeric(txtPrintToEx.Text) =

False Then _

MsgBox "The start or end pages to print is invalid.", 64

Exit Sub



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End If

End If

CD.ShowSave

If CD.FileName "" Then

If Dir(CD.FileName) "" Then

Ans% = MsgBox("Do you want to overwrite this file ?", _

vbQuestion Or vbYesNo)

If Ans% = 6 Then

Overwrite = True

Else

Overwrite = False

End If

Else

Overwrite = FalseEnd If

If txtStartPageEx.Text = "" And txtPrintToEx.Text = "" Then

DataReport1.ExportReport

DataReport1.ExportFormats(CLng(Left$(cbExportType.List

_

(cbExportType.ListIndex), 1))).Key, CD.FileName, Overwrite, _

chkExport.Value * -1, rptRangeAllPages

Else

DataReport1.ExportReport DataReport1.ExportFormats _(CLng(Left$(cbExportType.List(cbExportType.ListIndex) _

, 1))).Key, CD.FileName, Overwrite, chkExport.Value * -1,

_

txtStartPageEx.Text, txtPrintToEx.Text

End If

End If

End Sub

The ExportReport method is used to export a report to a file. There are two primary file types,

HTML and text. Unicode versions of both types can also be exported. The ExportReport method has four

(five if all pages are not selected) variables which can be passed to the method. The first is the format

type in which the report will be exported. If this value is left blank, a dialog box will appear, asking the

user which format is preferred. There are various ways to pass the export type using code.



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AuthorrptTextBox Name txtAuthor

Font ArialFontSize 12DataField Author

DataMember Command1_GroupingrptLabel Name Label2

Caption Title:rptLabel Name Label3

Caption Year PublishedrptTextBox Name txtTitle

DataField TitleDataMember Command1

rptTextBox Name txtYearPublishedDataField Year PublishedDataMember Command1

rptFunction Name Function1

DataField TitleFunctionType 4 rptFuncCntDataMember Command1

rptLabel Name lbTotalBooksCaption Total Books by Author

rptLabel Name Label11Caption %p

rptLabel Name lbPageTitleCaption Page

rptLabel Name lbofCaption of

rptLabel Name Label4Caption %P

9. Run the project. Try the various combinations of report output.

How It Works

The Show method works as it does with a Visual Basic form. It has the report display to the

screen. Before displaying the report to the screen settings like StartupPosition and WindowState can beset. The same properties used to display Visual Basic forms can be used to tailor the placement and

position of the report on the screen when it is displayed.

The PrintReport is used to print the report directly to the printer. Setting the ShowVariable of the

PrintReport determines if the report will be automatically routed to the printer or if a dialog box will



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appear to ask the user the page range and number of copies to be printed. Setting the range determines

the pages that will be printed. If a value for the range is not set, all the pages will be printed.

The ExportReport method is a very powerful function. It can be used to export reports as text,HTML, or a user-defined HTML format. This method has six variables to set to control the way the

report will be exported to a file.

ExportReport(ExportFormat, filename, Overwrite, ShowDialog, Range, PageFrom, PageTo)

The ExportFormat variable (ExportFormats collection item) is used to set the type of file that

will be exported. This variable is a member of the ExportFormats collection. The ExportFormats is a

collection that stores the type of report formats that can be exported. The ListBox was populated with thedefault items of the ExportFormats collection. The first character of each item in the ListBox is the index

of that export type in the ExportFormats collection. The Left$ function is used to grab the number from

the item displayed in the ListBox.

The filename variable (a String value) is used to set the name of the file that will be generated. If

a full path (such as C:\data\mynewfile.html) is not defined, the current working folder will be used.

The overwrite variable (a Boolean value) is set to determine if a file already exists as defined by

the filename variable should be overwritten. If this value is set to False and a file does exist, then the

Export dialog box will appear as if the ShowDialog variable was set to True.

The ShowDialog variable (a Boolean value) determines is the Export File dialog box is shown. If

this value is True then the filename variable does not need to be set.

The Range variable(s) (a Long value) is set to determine the range of pages that will be exported.

Comments



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By using Visual Basic code, a programmer can create an application that generates reports with

or without any user intervention. This How-To could be a primer to create an application that prints large

reports at night or generates HTML pages to be displayed on the Web.


Documents

Leccion 10.3 - Data Report Con Codigo