VB编程代码100例（精选示例及解析）

Visual Basic (VB) 是一种广泛使用的、易于学习的编程语言，尤其适合初学者快速开发Windows应用程序。本文将精选部分常见且有用的VB编程示例，涵盖基本语法、用户界面设计、数据处理等方面，帮助读者快速掌握VB编程的核心概念与实用技巧。

一、基础语法示例

1. 输出Hello World

Private Sub Command1_Click()
    MsgBox "Hello, World!" '弹出对话框显示Hello World
End Sub

2. 变量声明与运算

Private Sub Command1_Click()
    Dim num1 As Integer, num2 As Integer, sum As Integer
    num1 = 10
    num2 = 20
    sum = num1 + num2
    MsgBox "两数之和为：" & sum '显示两数之和
End Sub

3. 条件判断

Private Sub Command1_Click()
    Dim age As Integer
    age = Val(InputBox("请输入您的年龄：")) '获取用户输入的年龄
    If age > 18 Then
        MsgBox "您是成年人。"
    Else
        MsgBox "您是未成年人。"
    End If
End Sub

4. 循环结构

Private Sub Command1_Click()
    Dim i As Integer
    For i = 1 To 5
        Print "这是第" & i & "次循环" '在窗体上打印多次
    Next i
End Sub

二、用户界面设计

5. 创建简单的登录界面

Private Sub Command1_Click()
    If Text1.Text = "admin" And Text2.Text = "123456" Then '检查用户名和密码
        MsgBox "登录成功！"
    Else
        MsgBox "用户名或密码错误！"
    End If
End Sub

6. 动态添加控件

Private Sub Command1_Click()
    Dim btn As CommandButton
    Set btn = Controls.Add("VB.CommandButton", "DynamicButton") '动态新增按钮
    btn.Caption = "新按钮"
    btn.Visible = True
    btn.Left = 100
    btn.Top = 100
End Sub

7. 列表框的数据操作

Private Sub Form_Load()
    ListBox1.AddItem "苹果"
    ListBox1.AddItem "香蕉"
    ListBox1.AddItem "橙子"
End Sub

Private Sub Command1_Click()
    MsgBox "您选择的水果是：" & ListBox1.List(ListBox1.ListIndex) '显示选中的水果
End Sub

三、数据处理

8. 数组操作

Private Sub Command1_Click()
    Dim arr(1 To 5) As Integer
    Dim i As Integer, total As Integer
    For i = 1 To 5
        arr(i) = i * 10
        total = total + arr(i)
    Next i
    MsgBox "数组元素总和为：" & total
End Sub

9. 文件读写

Private Sub Command1_Click()
    Dim fNum As Integer
    fNum = FreeFile() '获取可用的文件号
    Open "C:\test.txt" For Output As #fNum
    Print #fNum, "这是写入文件的一行文本。" '写入文件
    Close #fNum '关闭文件
End Sub

10. 数据排序

Private Sub Command1_Click()
    Dim data(1 To 5) As Integer
    Dim i As Integer, j As Integer, temp As Integer
    '初始化数组
    data(1) = 34: data(2) = 21: data(3) = 56: data(4) = 7: data(5) = 12
    '冒泡排序
    For i = 1 To 4
        For j = 1 To 5 - i
            If data(j) > data(j + 1) Then
                temp = data(j)
                data(j) = data(j + 1)
                data(j + 1) = temp
            End If
        Next j
    Next i
    '显示排序结果
    For i = 1 To 5
        Print data(i)
    Next i
End Sub

四、高级应用

11. 调用API函数

'在模块中声明API函数
Private Declare Function SetCursor Lib "user32" (ByVal hCursor As Long) As Long
Private Declare Function LoadCursor Lib "user32" Alias "LoadCursorA" (ByVal nInstance As Long, ByVal lpCursorName As Long) As Long
Public Const IDC_CROSS = 32515 '十字光标

Private Sub Command1_Click()
    Dim hCursor As Long
    hCursor = LoadCursor(0, IDC_CROSS) '加载十字光标
    SetCursor hCursor '设置光标样式
End Sub

12. 多线程操作模拟

VB本身不直接支持多线程，但可以通过Timer控件模拟异步任务。

Private Sub Timer1_Timer()
    Static count As Integer
    count = count + 1
    If count > 5 Then
        Timer1.Enabled = False
        MsgBox "模拟任务完成！"
    Else
        Debug.Print "正在处理任务 " & count & "..."
    End If
End Sub

Private Sub Command1_Click()
    Timer1.Interval = 1000 '设置定时器间隔为1秒
    Timer1.Enabled = True '启动定时器
End Sub

通过上述示例，读者可以了解到VB编程中常见且实用的技术点。掌握这些基础后，可以进一步探索数据库连接、网络编程、图形处理等高级主题，不断提升编程水平。希望本文能成为您学习VB编程路上的良好起点。