Help with text boxes and timer controls

Hello, I am very new to Visual Basic and have hit a couple snags. Below is all of my code. I am supposed to be making a program like a microwave. The text box that displays the time should only show 2 numbers for the minutes, a ":" and 2 numbers for the seconds. I have set the max length for the text box to 5 but when the buttons are clicked more than five numbers will show up. Also, the ":" doesn't stay in the middle, I have tried to use the substring to break the numbers up, but that isn't working for me.

My other problem is that this time that can be entered is also supposed to run like a timer. I have added the timer control and think that I need to use the interval to make this work, but I am not sure. I can't get the numbers back from the text box as an integer for that to work because option strict and VB won't let me....

Any help is really appreciated...

Champ0342


Option Strict On
Public Class Form1
Dim b(9) As String
Private Sub form1_load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

Dim display(9) As String
'button values
b(0) = "0"
b(1) = "1"
b(2) = "2"
b(3) = "3"
b(4) = "4"
b(5) = "5"
b(6) = "6"
b(7) = "7"
b(8) = "8"
b(9) = "9"

tbtime.Text = "00:00"
tbtime.MaxLength = 5

End Sub

Private Sub btnone_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnone.Click

tbtime.Text = tbtime.Text & b(1)

End Sub

Private Sub btntwo_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btntwo.Click

tbtime.Text = tbtime.Text & b(2)

End Sub

Private Sub btnthree_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnthree.Click

tbtime.Text = tbtime.Text & b(3)

End Sub

Private Sub btnfour_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnfour.Click

tbtime.Text = tbtime.Text & b(4)

End Sub

Private Sub btnfive_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnfive.Click

tbtime.Text = tbtime.Text & b(5)

End Sub

Private Sub btnsix_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnsix.Click

tbtime.Text = tbtime.Text & b(6)

End Sub

Private Sub btnseven_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnseven.Click

tbtime.Text = tbtime.Text & b(7)

End Sub

Private Sub btneight_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btneight.Click

tbtime.Text = tbtime.Text & b(8)

End Sub

Private Sub btnnine_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnnine.Click

tbtime.Text = tbtime.Text(0) & b(9)

End Sub

Private Sub btnzero_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnzero.Click

tbtime.Text = tbtime.Text & b(0)

End Sub

Private Sub btnstart_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnstart.Click

tmrtime.Enabled = True

If tmrtime.Enabled = True Then
pbwindow.BackColor = Color.Yellow
End If

End Sub

Private Sub btnstop_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnstop.Click
Dim pause As String
pause = "Pause"

tmrtime.Enabled = False

If tmrtime.Enabled = False Then
pbwindow.BackColor = Color.LightGray
End If

If tmrtime.Enabled = False Then
tbtime.Text = pause
End If

End Sub

Private Sub tbtime_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tbtime.TextChanged
tbtime.MaxLength = 5
End Sub
End Class

try this

Code:

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Public Class form1

    Private Sub form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        TextBox1.ReadOnly = True
        TextBox1.Text = "00:00"
    End Sub

    Private Sub btnAddMinute_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAddMinute.Click
        TextBox1.Text = TextBox1.Text.Substring(0, 3) & CType(Format(CType(TextBox1.Text.Substring(3, 2), Integer) + 1, "00"), String)
    End Sub

    Private Sub btnAddHour_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAddHour.Click
        TextBox1.Text = CType(Format(CType(TextBox1.Text.Substring(0, 2), Integer) + 1, "00"), String) & TextBox1.Text.Substring(2, 3)
    End Sub

End Class

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You should be using a TimeSpan object to store the time, then adding minutes and seconds to that value. You can then display the contents of that TimeSpan each time it changes.

As for using a Timer, many people are under the misconception that they are for measuring time. They are NOT. A Timer works like an alarm, NOT a stopwatch. If you want the display updated every second then you should use a Timer to trigger the update, but the Timer does NOT measure the elapsed time. For that you should use a TimeSpan object and a Stopwatch object. For instance, if you want to count down 5 minutes, you would create a TimeSpan object that represented 5 minutes. You then star a Stopwatch AND a Timer. Each time the Timer raised a Tick event you would get the Elapsed time from the Stopwatch, subtract it from the original TimeSpan and then display the result to the user.

this works

Code:

---

Public Class form1

    Dim timeStr As String = ""
    Dim numbersEntered As String = ""
    Dim tempStr As String = ""

    Private Sub form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        TextBox1.ReadOnly = True
        TextBox1.Text = "00:00"
        Timer1.Interval = 1000
    End Sub

    Private Sub btnStart_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnStart.Click
        If TextBox1.Text = "paused" Then TextBox1.Text = timeStr
        Timer1.Enabled = True
    End Sub

    Private Sub btnStop_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnStop.Click
        Timer1.Enabled = False
        TextBox1.Text = "paused"
    End Sub

    Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
        Dim strMinutes As String = CType(Format(CType(TextBox1.Text.Substring(3, 2), Integer) - 1, "00"), String)
        Dim strHour As String = Format(CType(TextBox1.Text.Substring(0, 2), Integer), "00")
        If CType(strMinutes, Decimal) = -1 Then
            If CType(TextBox1.Text.Substring(0, 2), Integer) > 0 Then
                strMinutes = 59
                strHour = CType(Format(CType(TextBox1.Text.Substring(0, 2), Integer) - 1, "00"), String)
                timeStr = strHour & ":" & strMinutes
                TextBox1.Text = timeStr
            Else
                Timer1.Enabled = False
                timeStr = "00:00"
                TextBox1.Text = timeStr
            End If
        Else
            timeStr = strHour & ":" & strMinutes
            TextBox1.Text = timeStr
        End If
    End Sub

    Private Sub btn1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn1.Click
        If tempStr.Length < 4 Then
            tempStr += "1"
            numbersEntered = tempStr
        End If
        numbersEntered = New String("0", 4 - numbersEntered.Length) & numbersEntered
        TextBox1.Text = numbersEntered.Substring(0, 2) & ":" & numbersEntered.Substring(2, 2)
    End Sub

    Private Sub btn2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn2.Click
        If tempStr.Length < 4 Then
            tempStr += "2"
            numbersEntered = tempStr
        End If
        numbersEntered = New String("0", 4 - numbersEntered.Length) & numbersEntered
        TextBox1.Text = numbersEntered.Substring(0, 2) & ":" & numbersEntered.Substring(2, 2)
    End Sub

    Private Sub btn3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn3.Click
        If tempStr.Length < 4 Then
            tempStr += "3"
            numbersEntered = tempStr
        End If
        numbersEntered = New String("0", 4 - numbersEntered.Length) & numbersEntered
        TextBox1.Text = numbersEntered.Substring(0, 2) & ":" & numbersEntered.Substring(2, 2)
    End Sub

    Private Sub btn4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn4.Click
        If tempStr.Length < 4 Then
            tempStr += "4"
            numbersEntered = tempStr
        End If
        numbersEntered = New String("0", 4 - numbersEntered.Length) & numbersEntered
        TextBox1.Text = numbersEntered.Substring(0, 2) & ":" & numbersEntered.Substring(2, 2)
    End Sub

    Private Sub btn5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn5.Click
        If tempStr.Length < 4 Then
            tempStr += "5"
            numbersEntered = tempStr
        End If
        numbersEntered = New String("0", 4 - numbersEntered.Length) & numbersEntered
        TextBox1.Text = numbersEntered.Substring(0, 2) & ":" & numbersEntered.Substring(2, 2)
    End Sub

    Private Sub btn6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn6.Click
        If tempStr.Length < 4 Then
            tempStr += "6"
            numbersEntered = tempStr
        End If
        numbersEntered = New String("0", 4 - numbersEntered.Length) & numbersEntered
        TextBox1.Text = numbersEntered.Substring(0, 2) & ":" & numbersEntered.Substring(2, 2)
    End Sub

    Private Sub btn7_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn7.Click
        If tempStr.Length < 4 Then
            tempStr += "7"
            numbersEntered = tempStr
        End If
        numbersEntered = New String("0", 4 - numbersEntered.Length) & numbersEntered
        TextBox1.Text = numbersEntered.Substring(0, 2) & ":" & numbersEntered.Substring(2, 2)
    End Sub

    Private Sub btn8_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn8.Click
        If tempStr.Length < 4 Then
            tempStr += "8"
            numbersEntered = tempStr
        End If
        numbersEntered = New String("0", 4 - numbersEntered.Length) & numbersEntered
        TextBox1.Text = numbersEntered.Substring(0, 2) & ":" & numbersEntered.Substring(2, 2)
    End Sub

    Private Sub btn9_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn9.Click
        If tempStr.Length < 4 Then
            tempStr += "9"
            numbersEntered = tempStr
        End If
        numbersEntered = New String("0", 4 - numbersEntered.Length) & numbersEntered
        TextBox1.Text = numbersEntered.Substring(0, 2) & ":" & numbersEntered.Substring(2, 2)
    End Sub

    Private Sub btn0_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn0.Click
        If tempStr.Length < 4 Then
            tempStr += "0"
            numbersEntered = tempStr
        End If
        numbersEntered = New String("0", 4 - numbersEntered.Length) & numbersEntered
        TextBox1.Text = numbersEntered.Substring(0, 2) & ":" & numbersEntered.Substring(2, 2)
    End Sub

    Private Sub btnClear_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClear.Click
        tempStr = ""
        TextBox1.Text = "00:00"
    End Sub
End Class

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