November 2011 ~ LEARN MS-ACCESS TIPS AND TRICKS

VBA Module Object and Methods

a.p.r. pillaiNovember 28, 2011Utilities No comments

Introduction.

VBA Module Object has several interesting methods and properties. Last week we saw how to insert a Click Event Procedure in a Form Module with a Function. You can find this blog post here.

I don’t say that the frm.Module.CreateEventProc() method, which we have tried, was an easy approach for writing a one-line statement in a Form Module. But, trying something different is always exciting programming like exploring the unknown. After all, it is there as part of the Application to explore and learn.

Today we will try an alternative and simple method for the same example we tried last week. That is to write all the program lines in a text file and load that program directly into the Form Module.

If you have tried last week’s example, we can use the same ‘Sample’ Form for today’s trial run, or do the following to get prepared:

Loading VBA Code from Text File.

Open a new Form in Design View.
Create a Command Button on the Detail Section of the Form.
While the Command Button is in the selected state display its Property Sheet (F4 or ALT+Enter).
Change the Name Property Value to cmdRun and the Caption Property Value to Run Report.
Save the Form with the name Sample.
If you have last week’s Sample form, then open it in Design View.
Display the Form Module, remove the existing program lines, and save the Form.
Open Notepad, copy and paste the following program lines into Notepad and save it as c:\windows\temp\vbaprg.txt:
```
Private Sub cmdRun_Click()

    DoCmd.OpenReport "myReport", acViewPreview

End Sub
```
Replace the report name "myReport" with one of your own Report Names from the database.

Open a Standard VBA Module, copy and paste the following main program into the Standard Module:

The LoadFromTextFile() Function.

Public Function LoadFromTextFile()
Dim frm As Form, frmName As String, ctrlName As String

frmName = "Sample"
'ctrlName = "cmdRun"

'Open the form in design view
DoCmd.OpenForm frmName, acDesign

'define the form object
Set frm = Forms(frmName)

'call the form's Module Object's AddFromFile() method
'to read the program from the text file
'and insert them into the Form Module
frm.Module.AddFromFile "c:\windows\temp\vbaprg.txt"

'Save and close the form with the code
DoCmd.Close acForm, frmName, acSaveYes

'Open the form in Normal view
DoCmd.OpenForm frmName, acNormal

End Function

Place the cursor in the middle of the Code and press F5 to run the Code.
Press ALT+F11 to display the Database window with the Sample Form open.
Click on the Command Button to open the Report in print preview.
Close the Report.
Change the Sample Form in Design View.
Open the form module and check for the program lines we have loaded from the vbaprg.txt file.

Technorati Tags: Form, Module, Text File

Earlier Post Link References:

Writing VBA-Code with VBA

a.p.r. pillaiNovember 20, 2011automatically, Functions, vba code No comments

Introduction.

To insert an Event Procedure in a Form or Report we will open the VBA Module and write the code manually. If we open the Class Module through the Event Property on the Property Sheet of a Control or Form (after setting the “[Event Procedure]” value in the Event property) then the procedure’s opening and closing statements (see the example given below) will be inserted by Microsoft Access automatically. After that, we insert the necessary body lines of the procedure manually between those opening and closing statements.

Sample empty Subroutine stub of Form_Current() Event Procedure is shown below:

Private Sub Form_Current()

End Sub

Let us do it differently this time by programming a Command Button Click event procedure automatically through VBA. We are going to insert a Command Button Click Event Procedure in a Form Module with the help of a Function Write_Code(). We learned something similar through an earlier article on the topic: Creating Animated Command Button with VBA.

A sample Trial Run.

In this trick, the Command Button is programmed automatically to open a Report in Print Preview. Following are the lines of VBA Code we are going to insert into the Form Module automatically:

Private Sub cmdRun_Click()

    DoCmd.OpenReport "myReport", acViewPreview

End Sub

Open a new blank Form in Design View.
Add a Command Button control on the Form.
While the Command button is in the selected state display its Property Sheet (F4 or ALT+Enter).
Change the Name Property Value to cmdRun.
Change the Caption Property Value to Run Report.
Save and close the Form with the name frmSample.
Open VBA Editing Window (ALT+F11) and insert a new Standard Module. You can toggle Database and Code Window with the ALT+F11 Keyboard shortcut.

Copy and Paste the following Code into the Standard Module and save it:

Public Function Write_Code(ByVal frmName As String, ByVal CtrlName As String)
Dim frm As Form, x, txt As String, ctrl As Control

DoCmd.OpenForm frmName, acDesign, , , , acHidden
Set frm = Forms(frmName)
Set ctrl = frm.Controls(CtrlName)
With ctrl
    If .OnClick = "" Then
       .OnClick = "[Event Procedure]"
    End If
End With

x = frm.Module.CreateEventProc("Click", ctrl.Name)

txt = "DoCmd.OpenReport " & Chr$(34) & "myReport" & Chr$(34) & ", acViewPreview"
frm.Module.InsertLines x + 1, txt

DoCmd.Close acForm, frmName, acSaveYes
DoCmd.OpenForm frmName, acNormal

End Function

Replace the Report name "myReport" with one of your own Report names in the program line: txt = "DoCmd.OpenReport " & Chr$(34) & "myReport" & Chr$(34) & ", acViewPreview".
Display the Debug Window (Ctrl+G).
Type the following line in the Debug Window and press Enter Key:
```
Write_Code "frmSample","cmdRun"
```
The Form’s name "frmSample" is passed as the first parameter to the Write_Code() Function and Command Button’s name "cmdRun" is as the second parameter.
Press ALT+F11 to display the Database window. You can see that frmSample is already open in normal view after inserting the program lines in its Code Module.
Click on the Command Button to open your Report in Print Preview with the cmdRun_Click() Event Procedure. You may change the Form View into Design View, open the Form Module, and check the lines of Code we have inserted in there.

At the beginning of the above program the OnClick Event Property is checked, for the presence of any programmed action, like Macro Name, and if found empty, then inserts the text "[Event Procedure]" in the property in preparation for writing the program lines in the VBA Module.

In the next step, the Form Module’s CreateEventProc() method is called to create the Click Event Procedure of the Command Button: cmdRun. If you want a Double-Click Event procedure, rather than a Click() event procedure, then change the word "Click" to "dblClick".

Replace the DoCmd.OpenReport statement with appropriate Code for other actions like MouseMove.

You can call the Write_Code() function from a Command Button and click Event Procedure on a Form. Create two TextBoxes on the Form, enter the Form Name and Control Names in them respectively, and use the text box names in both parameters of the Write_Code() function.

Earlier Post Link References:

Control SetFocus on Tab Page Click

a.p.r. pillaiNovember 11, 2011Forms, SetFocus, Tab-Page No comments

Introduction

"When I click on a Tab Control Page I want to set focus on a particular Text box on that page, not on the first Text box on the Tab page, how?"

The above question was raised in an MS-Access Discussion Forum on the Net. The user tried a similar set of the sample code given below (with one of the three lines, inter-changeably) on the Page2_Click() Event procedure to move the focus to the "Ship City" Field on the tab page, but none of those lines worked, why?:

Private Sub Page2_Click()
     Forms!frm_Main![Ship City].SetFocus 
     frm_MainMenu![Ship City].SetFocus 
     me.[Ship City].SetFocus 
End Sub

Tab Control-based Menus.

Tab-Control is an interesting piece of Object to use on a Form. I have used this control mainly for building form-based Menus with List Boxes on them. You can find a sample image of a Control Screen below with List box-based Menus on it:

The middle of the Control Form shows a list as a menu of choices. In fact, there are fifteen different sets of menus displayed there. They are displayed one over the other by clicking on a set of Command Buttons, shown on either side of the list box. You can learn this trick here.

Use Change Event for Click Event.

Coming back to the topic, the first thing that you should know is that when you click on the Tab-Page Button (see the sample image below) on a Tab-Control the Click Event procedure will not be fired, instead it fires the Change() Event. So use the Change() Event for Tab Page Clicks.

The Click event fires only when you click on the top border area, to the right of the Tab Pages. So you need two clicks, one click on the Tab-Page button to make that page content visible followed by another click on the top border of Tab Control to run the Event Procedure so that whatever Code you put in the procedure is executed. This is not an attractive proposition, but we will take an alternative route to do it with a single click, using a different approach.

If you have already visited the above text links that I have suggested, then you are armed with a few ideas and you are already ahead of me on what I am going to say here.

Single Click Solution.

The simple method is using the Change Event Procedure on the TabPage Click.

We will implement the following ideas for a different approach:

Create a separate Command Button for each Tab-Page, with one line of VBA code to make it current or visible.
In the Command Button Click Event Procedure, we will add one more line of code to move the focus to a particular text box in the middle of the tab page.
Since we have Command Buttons to display Tab Pages we will hide the Tab-Page Buttons of the Tab-control. Optionally, change the Tab-control’s back-style design to transparent to make the tab control’s border design invisible.

Skipping the Fancy Work.

Before going into the detailed design of the above steps I can give you a very simple solution if you are not interested to go into all the fancy work. Set the Tab Index Property Value of the Text box (like [Ship City]) to 0 (zero).

Don’t mix up Tab Index with Tab Control and Tab Page. When you tap on the Tab-Key on the Keyboard the cursor jumps from one control (Text Box, Combo box, Check-box, etc.) to the next based on the sequence of the TabIndex Property Value.

This value is sequentially numbered from 0 to the number of such controls with TabIndex Property on a Form. This is automatically set sequentially in the order in which you place the controls on the form at design time manually or through Form Wizards. When a Form opens the control with Tab Index value 0 will get focused by default, irrespective of its physical placement on the form.

So, if the [Ship City] Field is not the starting point on your form and you want to make it so then do the following:

Open the form in design view.
Click on the [Ship City] field to select it.
Display its Property Sheet (F4 or ALT+Enter).
Find the Tab Index Property and change the Value to 0. Other controls’ Tab Index Property values will be automatically changed by Access. You must review and change them, if needed, to bring them in the desired order.

NB: Each Tab Page is like a separate sub-form and has a separate set of Tab Index sequence numbers starting with zero on them, even if you place a different group of fields of the current record.

Showing your Professionalism.

Now, that you are already armed with an easy solution, you may be interested to learn some fancy tricks on the Tab Control programming too.

A database can be filled with data very easily. Any Tom, Dick, and Harry can build a database to do that, with whatever easy method available to him. If it is for his own use then no issues. But, when it is presented to a Client/User it should have an impressive appearance and should be user-friendly. Besides that, it gives you a chance to advertise your professionalism in your work too.

Coming back to the topic, we will now take the first three steps of action, we have defined above, for a different approach to solve the problem. A sample design of a Form, with a Tab Control with three pages to hold different groups of information from the Orders Table of Northwind sample database. You may use any table you like to design a similar Form, with three Command Buttons on the left side of the Tab Control for a trial run:

The Design Task

Click on the first Command Button to select it.
- Display its Property Sheet (F4 or ALT+Enter keys).
- Change the Name Property Value to cmdOrder and the Caption property value to Order Details.
- Click on the Event Tab of the Property Sheet, select On Click Event property, and select [Event Procedure] from the drop-down control.
- Click on the Build ( . . . ) Button to open the Form’s VBA Module with an empty sub-routine stub.
- Copy and paste the following lines of Code, over-writing the existing lines, or simply copy the middle line alone and paste it between the sub-routine opening and closing lines, as shown below.
```
Private Sub cmdOrder_Click()
  Me.TabCtl0.Pages(0).SetFocus
End Sub
```
Similarly, change the middle Command Button’s Name Property Value to cmdShipper and Caption Property Value to Shipper Details.
- Follow the last three steps mentioned above to copy-paste the following code for the middle Command Button Click Event Procedure:
```
Private Sub cmdShipper_Click()
  Me.TabCtl0.Pages(1).SetFocus
  Me.Ship_City.SetFocus
End Sub
```
  In the first line code, we have changed the Tab page reference Page(0) to Page(1) refers to the second page of the Tab Control. Here we have added one more line Me.Ship_City.SetFocus to move the insertion point to the “Ship City” field, wherever it is physically placed. So, with one click on the Command Button will select the second page of the Tab Control and will set the focus on the Ship City field too.
  We are addressing the control (Me.Ship_City.SetFocus) as if it is directly placed on the Form surface rather than as a child control on the Tab Page. Remember, each group of fields on each Tab Page has a separate set of Tab Index sequence numbers starting from 0, to move the cursor around on that page.
  So, if you set the reference of the “Ship City” field as a child control on Tab Page2, like Me.TabCtl0.Pages(1).Controls("Ship City").SetFocus, it is equally valid.
Change the last Command Button’s Name Property Value to cmdPayment and Caption Property Value Payment Details.
- Copy-paste the following lines of code for the last Command Button Click Event Procedure, as you did in the earlier two cases:
```
Private Sub cmdPayment_Click()
   Me.TabCtl0.Pages(2).SetFocus
End Sub
```
Save the Form and open it in the normal view. When you open the form, by default Page1 of the tab control will be active.
Click on the middle Command Button. You can see the second page of the Tab Control become active and the control "Ship City" field is in focus now.
Click on the Payment Details Command Button to select the third page. You may try all the command buttons repeatedly to get the feel of their usage.
Since our command buttons took over the function of Tab-Pages of the Tab Control Object we don't need the Tab Control Page buttons above and we will remove them.
Change the Form Mode in Design View.
Click on the Tab Control by clicking on the right side of the Page3 button.
Display the Property Sheet (F4).
Click on the All tab of the property sheet and set the Style Property Value to None from the drop-down list.

The Demo Run.

If you open the Form in normal view the Tab Control will look like the image given below, without the Tab Page indicators. Clicking on the Command Buttons will turn the Pages, as before. You can do a magic trick by completely hiding the Tab Control's identity marks by setting the Back Style Property Value Transparent.

Change the form to design view (if the form is in normal view) and change the Back Style Property Value Transparent.
Save the Form and open it in Normal View.
No sign of the Tab Control now, except displaying the controls on the first Tab Page with their values and labels. Click on the Command Buttons one after the other. You will find that the data fields and their labels appear from nowhere occupying the same area every time, like magic.