qddxzl-302

程序在运行后结果为0
反复测试没有结果，为什么？请求高手指点




Public Class Form1
    Sub f(ByVal n As Integer, ByVal t As Double)
        Dim i As Integer
        t = 1
        For i = 1 To n
            t = t * i

        Next

    End Sub

    Private Sub Form1_click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim a As Double, b As Double, c As Double
        Dim sum As Double
        Call f(3, a)
        Call f(5, b)
        Call f(8, c)
        sum = a + b + c
        MsgBox(sum)
    End Sub

  
End Class

  程序在运行时出现“aihao“没有注明

Public Class Form1

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim sex As String
        Dim aihao As String
        If Radioboy.Checked = True Then
            sex = "男"
        Else
            sex = "女"
        End If
        If CheckBox1.Checked = True Then
            aihao = CheckBox1.Text
        End If
        If CheckBox2.Checked = True Then
            aihao = aihao + " " + CheckBox2.Text
        End If
        If CheckBox3.Checked = True Then
            aihao = aihao + " " + CheckBox3.Text
        End If
        If CheckBox4.Checked = True Then
            aihao = aihao + " " + CheckBox4.Text
        End If
        If CheckBox5.Checked = True Then
            aihao = aihao + " " + CheckBox5.Text
        End If
        Label3.Text = "姓名： " + STUNAME.Text + vbCrLf + "年龄 :" + STUAGE.Text + vbCrLf + "性别： " + sex + vbCrLf + "爱好 :" + aihao

    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim sex As String
        Dim aihao As String
        If Radioboy.Checked = True Then
            sex = "男"
        Else
            sex = "女"
        End If
        If CheckBox1.Checked = True Then
            aihao = CheckBox1.Text
        End If
        If CheckBox2.Checked = True Then
            aihao = aihao + " " + CheckBox2.Text
        End If
        If CheckBox3.Checked = True Then
            aihao = aihao + " " + CheckBox3.Text
        End If
        If CheckBox4.Checked = True Then
            aihao = aihao + " " + CheckBox4.Text
        End If
        If CheckBox5.Checked = True Then
            aihao = aihao + " " + CheckBox5.Text
        End If
        Label3.Text = "姓名： " + STUNAME.Text + vbCrLf + "年龄 :" + STUAGE.Text + vbCrLf + "性别： " + sex + vbCrLf + "爱好 :" + aihao

    End Sub
End Class