vb加减乘除运算程序

以下是用 VB 编写的简单加减乘除运算程序示例：

Public Class Form1
    Dim num1 As Double
    Dim num2 As Double
    Dim result As Double

    Private Sub btnAdd_Click(sender As Object, e As EventArgs) Handles btnAdd.Click
        '加法运算
        num1 = CDbl(txtNum1.Text)
        num2 = CDbl(txtNum2.Text)
        result = num1 + num2
        txtResult.Text = result.ToString()
    End Sub

    Private Sub btnSubtract_Click(sender As Object, e As EventArgs) Handles btnSubtract.Click
        '减法运算
        num1 = CDbl(txtNum1.Text)
        num2 = CDbl(txtNum2.Text)
        result = num1 - num2
        txtResult.Text = result.ToString()
    End Sub

    Private Sub btnMultiply_Click(sender As Object, e As EventArgs) Handles btnMultiply.Click
        '乘法运算
        num1 = CDbl(txtNum1.Text)
        num2 = CDbl(txtNum2.Text)
        result = num1 * num2
        txtResult.Text = result.ToString()
    End Sub

    Private Sub btnDivide_Click(sender As Object, e As EventArgs) Handles btnDivide.Click
        '除法运算
        num1 = CDbl(txtNum1.Text)
        num2 = CDbl(txtNum2.Text)
        If num2 = 0 Then
            MessageBox.Show("除数不能为0！", "错误", MessageBoxButtons.OK, MessageBoxIcon.Error)
        Else
            result = num1 / num2
            txtResult.Text = result.ToString()
        End If
    End Sub
End Class

该程序包含4个按钮事件处理程序，分别实现加法、减法、乘法和除法运算。其中，CDbl()函数用于将文本框中的字符串转换为 Double 类型，ToString()函数用于将运算结果转换为字符串类型。注意，在除法运算时需要判断除数是否为0。