Form’s Events ISYS 562

Form Events Opening & closing form:Open, Close, Load, Unload Moving to and from the form: Activate, deactivate Moving from control to control: Enter, Exit, Getfocus, Lostfocus Pressing keys: KeyDown, KeyUp, KeyPress Clicking mouse: Click, DblCLick, MouseUp, MouseWheel Changing data: dirty, BeforeUpdate, AfterUpdate, Undo Adding records: BeforeInsert, AfterInsert Deleting records: Delete, BeforeDelConfirm, AfterDelConfirm Filtering records: Filter, ApplyFilter

Order of events for controls on forms

Moving the focus to a control When you move the focus to a control on a form— for example, by opening a form that has one or more active controls or by moving to another control on the same form— the Enter and GotFocus events occur in this order:Enter → GotFocus If you are opening a form, these events occur after the events associated with opening the form (such as Open, Activate, and Current), as follows: –Open (form) → Activate (form) → Current (form) → Enter (control) → GotFocus (control) When the focus leaves a control on a form— for example, when you close a form that has one or more active controls or move to another control on the same form— the Exit and LostFocus events occur in this order:Exit → LostFocus If you are closing a form, the Exit and LostFocus events occur before the events associated with closing the form (such as Unload, Deactivate, and Close), as follows: –Exit (control) → LostFocus (control) → Unload (form) → Deactivate (form) → Close (form)

Changing and updating data in a control When you enter or change data in a control on a form and then move the focus to another control, the BeforeUpdate and AfterUpdate events occur: –BeforeUpdate → AfterUpdate The Exit and LostFocus events for the changed control occur after the BeforeUpdate and AfterUpdate events: –BeforeUpdate → AfterUpdate → Exit → LostFocus When you change the text in a text box or in the text box portion of a combo box, the Change event occurs. This event occurs whenever the contents of the control change, but before you move to a different control or record (and thus, before the BeforeUpdate and AfterUpdate events occur). The following sequence of events occurs for each key you press in a text box or in the text box portion of a combo box: –KeyDown → KeyPress → Dirty → Change → KeyUp The NotInList event occurs after you enter a value in a combo box that isn't in the combo box list and then attempt to move to another control or record. It occurs after the keyboard events and the Change events for the combo box, but before any other control or form events. If the LimitToList property of the combo box is set to Yes, the Error event for the form occurs immediately after the NotInList event: KeyDown → KeyPress → Dirty → Change → KeyUp → NotInList → Error

Order of events for records on forms Events occur for records on forms when you move the focus to a record, update data in a record, delete an existing record or records, or create a new record.

Moving the focus to records and updating data in records When you move the focus to an existing record on a form, enter or change data in the record, and then move the focus to another record, the following sequence of events occurs for the form: –Current (form) → BeforeUpdate (form) → AfterUpdate (form) → Current (form) When you leave the record whose data has changed, but before you enter the next record, the Exit and LostFocus events occur for the control with the focus. These events occur after the BeforeUpdate and AfterUpdate events for the form, as follows: BeforeUpdate (form) → AfterUpdate (form) → Exit (control) → LostFocus (control) → RecordExit (form) → Current (form) As you move the focus among the controls on a form, events occur for each control. For example, the following sequences of events occur when you: Open a form and change data in a control: Current (form) → Enter (control) → GotFocus (control) → BeforeUpdate (control) → AfterUpdate (control) Move the focus to another control: Exit (control1) → LostFocus (control1) → Enter (control2) → GotFocus (control2) Move the focus to another record: BeforeUpdate (form) → AfterUpdate (form) → Exit (control2) → LostFocus (control2) → RecordExit (form) → Current (form)

Changing and updating data in a control When you enter or change data in a control on a form and then move the focus to another control, the BeforeUpdate and AfterUpdate events occur. The Exit and LostFocus events for the changed control occur after the BeforeUpdate and AfterUpdate events: –BeforeUpdate → AfterUpdate → Exit → LostFocus

Deleting records When you delete a record, the following events occur for the form, and Microsoft Access displays a dialog box asking you to confirm the deletion: –Delete → BeforeDelConfirm → AfterDelConfirm If you cancel the Delete event, the BeforeDelConfirm and AfterDelConfirm events don't occur and the dialog box isn't displayed.

Creating a new record When you move the focus to a new (blank) record on a form and then create a new record by typing in a control, the following sequence of events occurs: –Current (form) → Enter (control) → GotFocus (control) → BeforeInsert (form) → AfterInsert (form) The BeforeUpdate and AfterUpdate events for the controls on the form and for the new record occur after the BeforeInsert event and before the AfterInsert event.

Keyboard events When you press and release a key while a control on a form has the focus (or use the SendKeys action to send a keystroke), the following sequence of events occurs: –KeyDown → KeyPress → KeyUp

Mouse Events When you press and release a mouse button while the mouse pointer is on a control on a form, the following sequence of events occurs for the control: –MouseDown → MouseUp → Click If a control has the focus and you click another control to move the focus to this second control, the following sequences of events occur: –First control: Exit → LostFocus –Second control: Enter → GotFocus → MouseDown → MouseUp → Click

VB Modules Standard modules: –Standard modules are separated database objects containing one or many procedures. They most often contains utilities functions that are useful in many different circumstances. –Create a standard module: In the database window, click Modules and New. Form/Report modules: Containing procedures belong to a form/report –Create a form module: In the Form Design view, click the Code button

VB Editor

Event Procedure Create an event procedure: –Select control –Select control’s event Event procedure’s argument: Private Sub CITY_BeforeUpdate(Cancel As Integer) End Sub Private Sub CITY_KeyDown(KeyCode As Integer, Shift As Integer) End Sub Private Sub Command10_Click() End Sub

Keep ComboBox (listBox) Synchronized with the Form Use Form’s OnCurrent event: –Example: A form to display employee table with a comboBox of empID: ComboBoxName = EmpID

Filtering Form Data Filter By Selection button (Form View Toolbar or Format Toolbar) –Example: While viewing employee record, click Race field, and click Filter By Selection button. –Click the Remove Filter to remove the filter. Filter By Form button: –Click the button –Click the field and select a value (may select many fields) Advanced Filter/Sort : –Format toolbar: Record/Filter –QBE window

Form’s Filter Event Triggered when a user chooses the Filter By Form or Advanced Filter/Sort command.

Form’s Filtering Properties Form’s Filter property: –Me.Filter = “sex = ‘male’” Form’s FilterOn property –True if we apply the filter

Using Filter Properties Private Sub Command16_Click() Me.Filter = "race='" & Race & "'" Me.FilterOn = True End Sub Private Sub Command17_Click() Me.FilterOn = False End Sub

Automatically Fill an Unbound Textbox with a Calculated Result Example: –Employee pays $50 for an event if salary<50000 –Otherwise, $100. Private Sub Form_Current() List14 = EmpID If Salary <= Then Text24 = 50 Else Text24 = 100 End If End Sub

Label Format –Caption, Visible Data –SmartTag Event Other –Name –ControlTip text

TextBox Format –Format, Visible Data –Control source –Inputmask –Validation rule –Default value –Smart tags Event –OnDirty, BeforeUpdate, AfterUpdate

Creating a Bound Form Using Design View Form: Record source Textbox: –Control source –Format –Inputmask Buttons: Move Next, Move Previous

SmartTag with a TextBox Name address

Using Textbox’s Events After entering annual income in an unbound box, Use the BeforeUpdate to check input, then use the AfterUpdate event to display event ticket fee based on the following rules: –If income <= then Fee = 100 –Else Fee = 200 Private Sub Text6_AfterUpdate() If Text6 <= Then Text8 = 100 Else Text8 = 200 End If End Sub Private Sub Text6_BeforeUpdate(Cancel As Integer) If Text6 <= Then MsgBox ("Must be greater than 10000") Cancel = True End If End Sub

Required Field Use textbox’s validation rule: –Not Null Use textbox’s BeforeUpdate event: –If isNull(text2) then Msgbox(“Must enter a value”) Cancel=true –End if

Responding to Keyboard Events Events: –KeyPress: Normal characters –Letters, numbers –KeyDown, KeyUp: Handle the exact keys that are being pressed including combinations that use special keys such as Shift, Alt, Ctrl

VBA Constants In VB Editor view: –View/Object Browser –Choose VBA Type constant to search –Color Constants –Key Code constants

KeyDown Event Arguments Textbox: City –Private Sub CITY_KeyDown(KeyCode As Integer, Shift As Integer) –KeyCode: –Shift: = 1 if Shift key is pressed = 2 if Control key is pressed = 3 if Alt key is pressed

Example of Using KeyDown Event to Enter Data Private Sub CITY_KeyDown(KeyCode As Integer, Shift As Integer) If Shift = 2 Then If KeyCode = vbKey1 Then CITY = "san francisco" RATING = "A" ElseIf KeyCode = vbKey2 Then CITY = "los angeles" RATING = "A" End If End Sub

Option Group Option Group wizard Testing Option Group selection: –If Frame18 = 1 Then Me.Filter = "sex='male'" Else Me.Filter = "sex='female'" –End If

Private Sub Frame18_AfterUpdate() If Frame18 = 1 Then Me.Filter = "sex='male'" Else Me.Filter = "sex='female'" End If Me.FilterOn = True End Sub

CheckBox If checked, the checkbox has a value of -1 If unckecked, it has a value of 0. If Check17 = -1 Then MsgBox ("You check check17") Else MsgBox ("You uncheck chk17") End If

Option Box (Radio Button) If Option19 = -1 Then MsgBox ("You check OptionBox") Else MsgBox ("You uncheck OptionBox") End If

ListBox Format: –Column count Data: –Control source –Row source type –Row source Listbox’s value: –MsgBox (List23)

Access Macros ISYS 562

Macro’s Actions OpenForm, OpenReport TransferDatabase, TransferSpreadsheet OutputTo CopyDatabaseFile, CopyObject FindNext, FindRecord RunCode, RunCommand, RunSQL, RunApp, RunMacro SendObject SetValue

Macro Condition You can use any expression that evaluates to True/False or Yes/No in a macro condition. The macro will be executed if the condition evaluates to True. To add a condition: –At macro design view: View/Condition

Convert Macro to VB Tools/Macro/Convert macros to VB Each action is converted to an Access DoCmd command. To view DoCmd command: –Object Browser –Choose Access –Search DoCmd