Introduction to the Date/Time Picker Control

Description

One of the advantages of the date/time picker control is that it allows the user to select a time or a date value instead of typing it. This tremendously reduces the likelihood of mistakes.

To create a date/time picker control, from the Common Controls section of the Toolbox, click DateTimePicker and click the form or another container. The DateTimePicker control is based on the DateTimePicker class. Therefore, to programmatically, declare a variable of type DateTimePicker and initialize it appropriately. Here is an example:

Imports System.Drawing
Imports System.Windows.Forms

Module Exercise

    Public Class Starter
        Inherits Form

        Private DateOrTime As DateTimePicker

        Dim components As System.ComponentModel.Container

        Public Sub New()
            InitializeComponent()
        End Sub

        Public Sub InitializeComponent()
            DateOrTime = New DateTimePicker

            Controls.Add(DateOrTime)
        End Sub

    End Class

    Function Main() As Integer

        Dim frmStart As Starter = New Starter

        Application.Run(frmStart)

        Return 0
    End Function

End Module

In reality, the DateTimePicker control can be considered as two controls in one: you just have to choose which one of both controls you want to use.

After adding the DateTimePicker control to the form, to allow the user to set the dates and not the times on the control, set its Format property either to Long or to Short. If you are working programmatically, use the DateTimePickerFormat enumeration to select Long or Short and assign it to the Format property of the control. Here is an example:

Imports System.Drawing
Imports System.Windows.Forms

Module Exercise

    Public Class Starter
        Inherits Form

        Private Calendar As DateTimePicker

        Dim components As System.ComponentModel.Container

        Public Sub New()
            InitializeComponent()
        End Sub

        Public Sub InitializeComponent()
            Calendar = New DateTimePicker
            Calendar.Format = DateTimePickerFormat.Long

            Controls.Add(Calendar)
        End Sub

    End Class

    Function Main() As Integer

        Dim frmStart As Starter = New Starter

        Application.Run(frmStart)

        Return 0
    End Function

End Module

As described already, the date time picker is two controls in one object. To transform a date time picker into a time picker control, change its Format property to a Time value. You can also do this programmatically. Here is an example:

Imports System.Drawing
Imports System.Windows.Forms

Module Exercise

    Public Class Starter
        Inherits Form

        Private ShowTime As DateTimePicker

        Dim components As System.ComponentModel.Container

        Public Sub New()
            InitializeComponent()
        End Sub

        Public Sub InitializeComponent()
            ShowTime = New DateTimePicker
            ShowTime.Format = DateTimePickerFormat.Time

            Controls.Add(ShowTime)
        End Sub

    End Class

    Function Main() As Integer

        Dim frmStart As Starter = New Starter

        Application.Run(frmStart)

        Return 0
    End Function

End Module

Although optional, you should (with emphasis) also set the ShowUpDown Boolean property to True. Here is an example:

Public Sub InitializeComponent()
            ShowTime = New DateTimePicker
            ShowTime.Format = DateTimePickerFormat.Time
            ShowTime.ShowUpDown = True

            Controls.Add(ShowTime)
End Sub

This makes it a true time picker control:

If you do not set the ShowUpDown property to true, the control would display as a combo box and when the user clicks the arrow button, a calendar would come up, which does not make sense since the purpose of the control is to deal with time values.

1. Start a new Windows Application named GeorgetownCleaningServices2
2. In the Solution Explorer, right-click Form1.vb and click Rename
3. Type CleaningServices.vb and press Enter
4. Design the form as follows:
    

   Control Name Text Additional Properties GroupBox   Order Identification   Label   Customer Name:   TextBox txtCustomerName     Label   Customer Phone:   TextBox txtCustomerPhone     Label   Date Left:   DateTimePicker dtpDateLeft     Label   Time Left:   DateTimePicker dtpTimeLeft   Format: Time Label   Date Expected:   DateTimePicker dtpDateExpected     Label   Time Expected:   DateTimePicker dtpTimeExpected   Format: Time GroupBox   Order Processing   Label   Item Type   Label   Unit Price   Label   Qty   Label   Sub Total   Label   Shirts   TextBox txtShirtsUnitPrice 1.25 TextAlign: Right TextBox txtShirtsQuantity 0 TextAlign: Right TextBox txtShirtsSubTotal 0.00 TextAlign: Right Label   Pants   TextBox txtPantsUnitPrice 1.95 TextAlign: Right TextBox txtPantsQuantity   TextAlign: Right TextBox txtPantsSubTotal 0.00 TextAlign: Right ComboBox cbxItem1 None Items: None Women Suit Dress Regular Skirt Skirt With Hook Men's Suit 2Pc Men's Suit 3Pc Sweaters Silk Shirt Tie Coat Jacket Swede TextBox txtItem1UnitPrice 0.00 TextAlign: Right TextBox txtItem1Quantity 0 TextAlign: Right TextBox txtItem1SubTotal 0.00 TextAlign: Right ComboBox cbxItem2 None Items: None Women Suit Dress Regular Skirt Skirt With Hook Men's Suit 2Pc Men's Suit 3Pc Sweaters Silk Shirt Tie Coat Jacket Swede TextBox txtItem2UnitPrice 0.00 TextAlign: Right TextBox txtItem2Quantity 0 TextAlign: Right TextBox txtItem2SubTotal 0.00 TextAlign: Right ComboBox cbxItem3 None Items: None Women Suit Dress Regular Skirt Skirt With Hook Men's Suit 2Pc Men's Suit 3Pc Sweaters Silk Shirt Tie Coat Jacket Swede TextBox txtItem3UnitPrice 0.00 TextAlign: Right TextBox txtItem3Quantity 0 TextAlign: Right TextBox txtItem3SubTotal 0.00 TextAlign: Right ComboBox cbxItem4 None Items: None Women Suit Dress Regular Skirt Skirt With Hook Men's Suit 2Pc Men's Suit 3Pc Sweaters Silk Shirt Tie Coat Jacket Swede TextBox txtItem4UnitPrice 0.00 TextAlign: Right TextBox txtItem4Quantity 0 TextAlign: Right TextBox txtItem4SubTotal 0.00 TextAlign: Right GroupBox   Order Summary   Button btnCalculate Calculate   Label   Cleaning Total:   TextBox txtCleaningTotal 0.00 TextAlign: Right Label   Tax Rate:   TextBox txtTaxRate 7.75 TextAlign: Right Label   %   Label   Tax Amount:   TextBox txtTaxAmount 0.00 TextAlign: Right Label   Net Total:   TextBox txtNetPrice 0.00 TextAlign: Right Button btnClose Close

5. Right-click the form and click View Code

The time picker is meant either to only display a time to the user or to both display time and allow the user to specify a time. The control follows the format of the time values set in the regional settings of Control Panel. By default, in US English, the time is divided in four sections that include the hour value, the minute value, the second value, and the AM/PM side. These sections are separated by standard characters that also are specified in the regional settings of Control Panel.

To change the time, the user can click a section, such as the hour, the minute, the second, or the AP/PM side, then click one of the arrows of the spin button. The up button increases (only) the value of the selected section while the down button decreases (only) the value of the selected section. The user can also use the arrow keys to change the value of a section.

After changing the of the time, even the change occurs for only one section, the control fires a ValueChanged event, which is the default event of the control.

As mentioned already, the user changes the time by using the various sections of the controls. If the user changes the value of a section, it is considered that the whole time has been changed. At any time, the (current) time of the control is stored in the Value property. You can use this property either to programmatically change the time on the control or to get the time on the control.

1. In the Class Name combo box, select dtpTimeLeft
2. In the Method Name combo box, select ValueChanged and implement the event as follows:
    

   Private Sub dtpTimeLeftValueChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles dtpTimeLeft.ValueChanged Dim dateLeft As DateTime Dim timeLeft As DateTime Dim time9AM As DateTime dateLeft = dtpDateLeft.Value timeLeft = dtpTimeLeft.Value time9AM = New DateTime(timeLeft.Year, timeLeft.Month, timeLeft.Day, 9, 0, 0) ' If the customer leaves clothes before 9AM... If timeLeft <= time9AM Then ' ... then they should be ready the same day after 5PM dtpDateExpected.Value = dateLeft dtpTimeExpected.Value = New DateTime(dateLeft.Year, dateLeft.Month, dateLeft.Day, 17, 0, 0) Else ' If the clothes were left after 9AM, ' they will be available the following morning at 8AM dtpDateExpected.Value = New DateTime(dateLeft.Year, dateLeft.Month, dateLeft.Day + 1) dtpTimeExpected.Value = New DateTime(dateLeft.Year, dateLeft.Month, dateLeft.Day + 1, 8, 0, 0) End If End Sub

3. In the Class Name combo box, select btnCalculate
4. In the Method Name combo box, select Click and implement the event as follows:
    

   Private Sub btnCalculateClick(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnCalculate.Click Dim UnitPriceShirts As Double, UnitPricePants As Double Dim UnitPriceItem1 As Double, UnitPriceItem2 As Double Dim UnitPriceItem3 As Double, UnitPriceItem4 As Double Dim SubTotalShirts As Double, SubTotalPants As Double Dim SubTotalItem1 As Double, SubTotalItem2 As Double Dim SubTotalItem3 As Double, SubTotalItem4 As Double Dim QuantityShirts As Integer, QuantityPants As Integer = 1 Dim QuantityItem1 As Integer, QuantityItem2 As Integer = 1 Dim QuantityItem3 As Integer, QuantityItem4 As Integer = 4 Dim CleaningTotal As Double, TaxRate As Double Dim TaxAmount As Double, NetPrice As Double ' Retrieve the unit price of this item ' Just in case the user types an invalid value, ' we are using a try...catch Try UnitPriceShirts = CDbl(txtUnitPriceShirts.Text) Catch ex As Exception MsgBox("The value you entered for the price " & "of shirts is not valid" & vbCrLf & "Please try again") Exit Sub End Try ' Retrieve the number of this item ' Just in case the user types an invalid value, ' we are using a try...catch Try QuantityShirts = CInt(txtQuantityShirts.Text) Catch ex As Exception MsgBox("The value you entered for the number of & "shirts is not valid" & vbCrLf & "Please try again") Exit Sub End Try Try UnitPricePants = CDbl(txtUnitPricePants.Text) Catch ex As Exception MsgBox("The value you entered for the price of & "pants is not valid" & vbCrLf & "Please try again") Exit Sub End Try Try QuantityPants = CInt(txtQuantityPants.Text) Catch ex As Exception MsgBox("The value you entered for the number of & "pants is not valid" & vbCrLf & "Please try again") Exit Sub End Try If (cbxItem1.Text = "None") Or (cbxItem1.Text = "") Then QuantityItem1 = 0 UnitPriceItem1 = 0.0 Else Try UnitPriceItem1 = CDbl(txtUnitPriceItem1.Text) Catch ex As Exception MsgBox("The value you entered for the price is not valid" & vbCrLf & "Please try again") Exit Sub End Try Try QuantityItem1 = CInt(txtQuantityItem1.Text) Catch MsgBox("The value you entered is not valid" & vbCrLf & "Please try again") Exit Sub End Try End If If (cbxItem2.Text = "None") Or (cbxItem2.Text = "") Then QuantityItem2 = 0 UnitPriceItem2 = 0.0 Else Try UnitPriceItem2 = CDbl(txtUnitPriceItem2.Text) Catch MsgBox("The value you entered for the price is not valid" & vbCrLf & "Please try again") Exit Sub End Try Try QuantityItem2 = CInt(txtQuantityItem2.Text) Catch MsgBox("The value you entered is not valid" & vbCrLf & "Please try again") Exit Sub End Try End If If (cbxItem3.Text = "None") Or (cbxItem3.Text = "") Then QuantityItem3 = 0 UnitPriceItem3 = 0.0 Else Try UnitPriceItem3 = CDbl(txtUnitPriceItem3.Text) Catch ex As Exception MsgBox("The value you entered for the price is not valid" & vbCrLf & "Please try again") Exit Sub End Try Try QuantityItem3 = CInt(txtQuantityItem3.Text) Catch ex As Exception MsgBox("The value you entered is not valid" & vbCrLf & "Please try again") Exit Sub End Try End If If (cbxItem4.Text = "None") Or (cbxItem4.Text = "") Then QuantityItem4 = 0 UnitPriceItem4 = 0.0 Else Try UnitPriceItem4 = CDbl(txtUnitPriceItem4.Text) Catch ex As Exception MsgBox("The value you entered for the price is not valid" & vbCrLf & "Please try again") Exit Sub End Try Try QuantityItem4 = CInt(txtQuantityItem4.Text) Catch ex As Exception MsgBox("The value you entered is not valid" & vbCrLf & "Please try again") Exit Sub End Try End If ' Calculate the sub-total for this item SubTotalShirts = QuantityShirts * UnitPriceShirts SubTotalPants = QuantityPants * UnitPricePants SubTotalItem1 = QuantityItem1 * UnitPriceItem1 SubTotalItem2 = QuantityItem2 * UnitPriceItem2 SubTotalItem3 = QuantityItem3 * UnitPriceItem3 SubTotalItem4 = QuantityItem4 * UnitPriceItem4 ' Calculate the total based on sub-totals CleaningTotal = SubTotalShirts + SubTotalPants + SubTotalItem1 + SubTotalItem2 + SubTotalItem3 + SubTotalItem4 TaxRate = CDbl(txtTaxRate.Text) ' Calculate the amount owed for the taxes TaxAmount = CleaningTotal * TaxRate / 100 ' Add the tax amount to the total order NetPrice = CleaningTotal + TaxAmount ' Display the sub-total in the corresponding text box txtSubTotalShirts.Text = FormatNumber(SubTotalShirts) txtSubTotalPants.Text = FormatNumber(SubTotalPants) txtSubTotalItem1.Text = FormatNumber(SubTotalItem1) txtSubTotalItem2.Text = FormatNumber(SubTotalItem2) txtSubTotalItem3.Text = FormatNumber(SubTotalItem3) txtSubTotalItem4.Text = FormatNumber(SubTotalItem4) txtCleaningTotal.Text = FormatNumber(CleaningTotal) txtTaxAmount.Text = FormatNumber(TaxAmount) txtNetPrice.Text = FormatNumber(NetPrice) End Sub

5. In the Class Name combo box, select btnClose
6. In the Method Name combo box, select Click and implement the event as follows:
    

   Private Sub btnCloseClick(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnClose.Click End End Sub

7. Execute the application and create a few orders
    
   
8. Close the form and return to your programming environment

By default, the time displays using the H:M:SS AM/PM format. This means that the time uses 1 digit for the hours from 0 to 9, 1 digit for the minutes from 0 to 9, 1 digit for the seconds from 0 to 9 and the AM or PM for morning or afternoon. To customize the way the time displays, first set the Format property to Custom. Then, in the CustomFormat property, use a combination of the following characters to create a custom format:

You can set the format at design time using the Format field on the Properties window. To set the format at run time, assign the desired format to the DateTimePicker.CustomFormat property.

By default, after adding the control to the form or container, it assumes the time of the computer when the control was added. If you want to set a different time, apply a Format combination to the Value property. In the same way, at any time, you can retrieve the time value on the control by accessing the Value property.