Allowing only LETTERS in a textbox

Private Sub TextBox3_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox3.KeyPress

If Asc(e.KeyChar) < 65 Or Asc(e.KeyChar) > 90 AndAlso Asc(e.KeyChar) < 97 Or Asc(e.KeyChar) > 122 Then

MessageBox.Show("Only Letters")

e.Handled = True

ElseIf Asc(e.KeyChar) = 8 Then
e.Handled = False

End If
End Sub

Allow only LETTERS and Backspace in a textbox

Private Sub TextBox4_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox4.KeyPress

If (e.KeyChar >= "a" And e.KeyChar = "A" And e.KeyChar
e.Handled = False

Else
e.Handled = True
MessageBox.Show("Only Letters")

End If
End Sub

Allow NUMBERS, BACKSPACE and a DOT in a textbox

Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) _
Handles TextBox1.KeyPress

'There are a couple scenerios this code is looking for. One is checking for the Decimal period "."
'and whether it exists in the textbox already. The other is seeing if the keypress was a Number and
'Control based key.


If e.KeyChar = "." Then


'If a value higher than -1 is returned, it means there IS a existing decimal point’


If TextBox1.Text.IndexOf(".") > -1 Then

'This says that I already dealt with the _KeyPress event so do not do anything else with this event.


e.Handled = True

End If

'Remember you want numbers to get through and the Control keys like “Backspace”

ElseIf Char.IsNumber(e.KeyChar) = False AndAlso Char.IsControl(e.KeyChar) = False Then

'This says that I already dealt with the _KeyPress event so do not do anything else with this event.

e.Handled = True

End If
End Sub

Date and Time Difference user interface:

here is the CODE:

Public Class frmDateandTimeDifference

Private Sub btnGettheDifference_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnGettheDifference.Click

Dim Diff1, Diff2, Diff3 As Long

Select Case cboSelect.SelectedIndex

Case 0
Diff1 = DateDiff(DateInterval.Year, dtpStartDate.Value, dtpEndDate.Value)
Diff2 = DateDiff(DateInterval.Month, dtpStartDate.Value, dtpEndDate.Value)
Diff3 = DateDiff(DateInterval.Day, dtpStartDate.Value, dtpEndDate.Value)
lblOutput.Text = Diff1 & " Year/s " & Diff2 & " Month/s " & Diff3 & " Day/s "

Case 1
Diff1 = DateDiff(DateInterval.Hour, dtpStartTime.Value, dtpEndTime.Value)
Diff2 = DateDiff(DateInterval.Minute, dtpStartTime.Value, dtpEndTime.Value)
Diff3 = DateDiff(DateInterval.Second, dtpStartTime.Value, dtpEndTime.Value)
lblOutput.Text = Diff1 & " Hour/s " & Diff2 & " Minute/s " & Diff3 & " Second /s "

End Select
End Sub

Private Sub frmDateandTimeDifference_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

cboSelect.Items.Add("Year, Month, Day")
cboSelect.Items.Add("Hour, Minute, Second")
End Sub

Private Sub Label6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Label6.Click

Me.Close()
End Sub

End Class

**Run and Save the program.....

Proper Case

1. Proper Case user interface:



2. Code....

Public Class frmProperCase

Private Sub btnConvert_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnConvert.Click

txtProperCase.Text = Microsoft.VisualBasic.StrConv(txtInput.Text, VbStrConv.ProperCase)
End Sub

Private Sub Label2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Label2.Click

Me.Close()
End Sub

End Class

3. Save and RUN the program...

Character Count

1. Character Count user interface:



2. The Code....

Public Class frmCharacterCount

Private Sub btnClickHereToCount_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClickHereToCount.Click

Dim length, x, count As Integer
Dim letter As String

length = Microsoft.VisualBasic.Len(txtPhrase.Text)

For x = 1 To length

letter = Microsoft.VisualBasic.Mid(txtPhrase.Text, x, 1)

If Microsoft.VisualBasic.StrComp(letter, txtcharacter.Text, CompareMethod.Text) = 0 Then

count = count + 1
End If

Next

lblOutput.Text = "There are " & count & " " & txtcharacter.Text & " in the Phrase."
End Sub

Private Sub exit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles exit.Click

Me.Close()
End Sub
End Class

3. Save and RUN the program...

Button Play

1.A program that will initially display two buttons, the first is enabled and the other is disabled. The behavior will be, once you click the Enabled button, it will be disabled, while the other button (which is disabled) will be enabled.



2. CODE:


Public Class frmButtonPlay

Private Sub btn1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn1.Click

btn1.Enabled = False
btn2.Enabled = True
End Sub


Private Sub btn2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn2.Click

btn2.Enabled = False
btn1.Enabled = True
End Sub

Private Sub backtoindex_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles backtoindex.Click

Me.Close()
End Sub

Private Sub frm2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

btn1.Enabled = True
btn2.Enabled = False
End Sub

End Class

3. Save & Run...