成功执行上一个操作后执行其他操作时，如何清除文本框？

Question

我正在使用Visual Basic创建一个简单的计算器...在成功执行上一个操作后执行另一个操作时，如何使文本框清晰？

这是我使用的代码...

Public Class Form1
    Dim FirstNum As Decimal
    Dim SecondNum As Decimal
    Dim Operations As Integer
    Dim Operator_Selector As Boolean = False


    Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click
        FirstNum = TextBox1.Text
        TextBox1.Text = "0"
        Operator_Selector = True
        Operations = 1 ' = +
    End Sub
    Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
        If TextBox1.Text <> "0" Then
            TextBox1.Text += "3"
        Else
            TextBox1.Text = "3"
        End If
    End Sub
    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        If TextBox1.Text <> "0" Then
            TextBox1.Text += "2"
        Else
            TextBox1.Text = "2"
        End If
    End Sub
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        If TextBox1.Text <> "0" Then
            TextBox1.Text += "1"
        Else
            TextBox1.Text = "1"
        End If
    End Sub
    Private Sub Button6_Click(sender As Object, e As EventArgs) Handles Button6.Click
        If TextBox1.Text <> "0" Then
            TextBox1.Text += "5"
        Else
            TextBox1.Text = "5"
        End If
    End Sub
    Private Sub Button5_Click(sender As Object, e As EventArgs) Handles Button5.Click
        If TextBox1.Text <> "0" Then
            TextBox1.Text += "4"
        Else
            TextBox1.Text = "4"
        End If

        If Flag = 1 Then
            TextBox1.Text = ""
            TextBox1.Text = TextBox1.Text + "1"
            Flag = 0
        Else
            TextBox1.Text = TextBox1.Text + "1"
        End If
    End Sub
    Private Sub Button7_Click(sender As Object, e As EventArgs) Handles Button7.Click
        If TextBox1.Text <> "0" Then
            TextBox1.Text += "6"
        Else
            TextBox1.Text = "6"
        End If
    End Sub
    Private Sub Button8_Click(sender As Object, e As EventArgs) Handles Button8.Click
        FirstNum = TextBox1.Text
        TextBox1.Text = "0"
        Operator_Selector = True
        Operations = 2 ' = -
    End Sub
    Private Sub Button12_Click(sender As Object, e As EventArgs) Handles Button12.Click
        FirstNum = TextBox1.Text
        TextBox1.Text = "0"
        Operator_Selector = True
        Operations = 3 ' = *
    End Sub
    Private Sub Button11_Click(sender As Object, e As EventArgs) Handles Button11.Click
        If TextBox1.Text <> "0" Then
            TextBox1.Text += "9"
        Else
            TextBox1.Text = "9"
        End If
    End Sub
    Private Sub Button10_Click(sender As Object, e As EventArgs) Handles Button10.Click
        If TextBox1.Text <> "0" Then
            TextBox1.Text += "8"
        Else
            TextBox1.Text = "8"
        End If
    End Sub
    Private Sub Button9_Click(sender As Object, e As EventArgs) Handles Button9.Click
        If TextBox1.Text <> "0" Then
            TextBox1.Text += "7"
        Else
            TextBox1.Text = "7"

        End If
    End Sub
    Private Sub Button16_Click(sender As Object, e As EventArgs) Handles Button16.Click, Button18.Click
        If Operator_Selector = True Then
            SecondNum = TextBox1.Text
            If Operations = 1 Then
                TextBox1.Text = FirstNum + SecondNum

            ElseIf Operations = 2 Then
                TextBox1.Text = FirstNum - SecondNum

            ElseIf Operations = 3 Then
                TextBox1.Text = FirstNum * SecondNum

            Else
                If SecondNum = 0 Then
                    TextBox1.Text = "Error"

                Else
                    TextBox1.Text = FirstNum / SecondNum
                End If
            End If
            Operator_Selector = False
        End If



    End Sub
    Private Sub Button13_Click(sender As Object, e As EventArgs) Handles Button13.Click
        If Not (TextBox1.Text.Contains(".")) Then
            TextBox1.Text += "."
        End If
    End Sub
    Private Sub Button14_Click(sender As Object, e As EventArgs) Handles Button14.Click
        If TextBox1.Text <> "0" Then
            TextBox1.Text += "0"
        End If
    End Sub
    Private Sub Button15_Click(sender As Object, e As EventArgs) Handles Button15.Click
        TextBox1.Text = "0"
    End Sub

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

    End Sub
End Class

请帮助我