编写VB程序,实现如下功能:在文本框Text1中输入十六进制数,单击“转换”按钮Command1,在列表框List1中输出对应的十进制数,运行界面如图所示,程序代码如下。

(1)要调整Label1中的字体大小,可选择在属性面板中设置Label1的
。(单选,填字母:A.Caption / B.Font /
(2)为实现上述功能,请在划线处填入合适的代码。
Private Sub Command1_Click()
Dim s As String, c As String, t As String
Dim i As Integer, b As Integer, ans As Long
Dim flag As Boolean
s =
①b = Len(s)
flag = True
ans = 0
For i =" 1" To b
c =" Mid(s," i, 1)
If c >= "0" And c <= "9" Then
ans =" ans" * 16 + Asc(c) - Asc("0")
ElseIf c >= "A" And c <= "F" Then
ans =" ans" * 16 +
②Else
③ '输入情况有误
Exit For
End If
Next i
If flag Then t =" Str(ans)" Else t ="输入有误!"
List1.AddItem s + "-->" + t
End Sub
(3)由上述算法可知,运行时在Text1框中输入“d8”,列表框List1中添加的条目为
。(单选,填字母:A. d8-->216/ B. d8-->输入有误!)