VB.NET按鈕事件問題

Question

我有問題，我的按鈕的代碼是一個按鈕。

Private Sub btnCalculateCosts_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnCalculateCosts.Click 

它處理：

' This Calculate Costs button click event handler edits the 
' registration(costs) form to ensure it contains valid data. 
' Then, after passing control to the business class, it 
' displays the registration cost. 

Dim objCourse As Course 
Dim objCourseCostsFile As Course 
Dim InputError As Boolean = False 

' Is student ID entered properly 
If Me.txtCorporateID.MaskFull = False Then 
    MessageBox.Show("Enter your Corporate ID in the Corporate ID box", "Error") 
    Me.txtCorporateID.Clear() 
    Me.txtCorporateID.Focus() 
    InputError = True 
' Is student name entered properly 
ElseIf Me.txtFirstName.TextLength < 1 Or _ 
    Me.txtFirstName.Text < "A" Then 
    MessageBox.Show("Please enter your first name in the First Name box", "Error") 
    Me.txtFirstName.Clear() 
    Me.txtFirstName.Focus() 
    InputError = True 
' Is number of units entered properly 
ElseIf Me.txtLastName.TextLength < 1 Or _ 
    Me.txtLastName.Text < "A" Then 
    MessageBox.Show("Please enter your last name in the Last Name box", "Error") 
    Me.txtLastName.Clear() 
    Me.txtLastName.Focus() 
    InputError = True 
' Is number of units entered properly 
ElseIf Not IsNumeric(Me.txtNumberOfDays.Text) Then 
    MessageBox.Show("Enter the units in the Number of Units box", "Error") 
    Me.txtNumberOfDays.Clear() 
    Me.txtNumberOfDays.Focus() 
    InputError = True 
' Has 1-4 units been entered 
ElseIf Convert.ToInt32(Me.txtNumberOfDays.Text) < 1 _ 
     Or Convert.ToInt32(Me.txtNumberOfDays.Text) > 4 Then 
    MessageBox.Show("Units must be 1 - 4", "Error") 
    Me.txtNumberOfDays.Clear() 
    Me.txtNumberOfDays.Focus() 
    InputError = True 
End If 

' If no input error, process the registration costs 
If Not InputError Then 
    If Me.radPreConferenceCourse.Checked = False Then 
     objCourse = New Course(txtCorporateID.Text, txtFirstName.Text, txtLastName.Text, txtNumberOfDays.Text) 
     Me.lblCosts.Visible = True 
     Me.lblCosts.Text = "Total Conference Costs Are: " & (objCourse.ComputeCosts()).ToString("C2") 
    Else 
     objCourse = New Course(txtCorporateID.Text, txtFirstName.Text, txtLastName.Text, txtNumberOfDays.Text, g) 
     Me.lblCosts.Visible = True 
     Me.lblCosts.Text = "Total Conference Costs Are: " & (objCourse.ComputeCosts()).ToString("C2") 
.... 

收到錯誤：

Handles clause requires a WithEvents variable defined in the containing type or one of its base types.

Answer 1

哪裏btnCalculateCosts定義？ - SLaks 14小時前