VB学习第二周--加法器的实现

加法器的实现:

Public Class Form1    Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged        If Not IsNumeric(TextBox1.Text) Then            TextBox1.Text = ""        End If    End Sub    Private Sub TextBox2_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox2.TextChanged        If Not IsNumeric(TextBox2.Text) Then            TextBox2.Text = ""        End If    End Sub    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click        TextBox3.Text = Val(TextBox1.Text) + Val(TextBox2.Text)    End Sub    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click        TextBox2.Text = ""        TextBox1.Text = ""        TextBox3.Text = ""        TextBox1.Focus()    End Sub    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click        End    End Sub    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load    End SubEnd Class