"大学计算机VB程序设计考试题目及四则运算窗体设计"

大学计算机VB程序设计考试题目.doc中，实验三第1题要求设计一个窗体，其中包括五个命令按钮，分别用于完成四则运算和退出程序。在计算除法时，如果第二个数为零，则需要在消息框中显示“除数为零”的信息。具体代码如下： Public Class Form1 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim a, b As Single a = TextBox1.Text b = TextBox2.Text TextBox3.Text = a + b End Sub Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click Dim a, b As Single a = TextBox1.Text b = TextBox2.Text TextBox3.Text = a - b End Sub Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click Dim a, b As Single a = TextBox1.Text b = TextBox2.Text TextBox3.Text = a * b End Sub Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click Dim a, b As Single a = TextBox1.Text b = TextBox2.Text If b = 0 Then MessageBox.Show("除数为零") Else TextBox3.Text = a / b End If End Sub Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click Me.Close() End Sub End Class 以上代码实现了四则运算功能，当用户点击除法按钮时，如果第二个数为零，则会在消息框中显示“除数为零”的信息。用户还可以点击退出按钮来关闭程序。这个窗体可以帮助用户进行简单的数学计算，并且能够处理除数为零的情况，提高程序的稳定性和用户体验。