vb练习题及答案

vb练习题及答案
VB练习题及答案
VB（Visual Basic）是一种广泛应用于Windows操作系统的编程语言，它以其简单易学的特点受到了许多初学者和专业开发者的青睐。

为了帮助大家更好地掌握VB编程，下面将提供一些VB练习题及其答案，希望能对大家有所帮助。

练习题一：计算器程序
编写一个VB程序，实现一个简单的计算器功能。

要求用户输入两个数字和一个操作符（+、-、*、/），然后根据操作符进行相应的计算，并输出结果。

解答：
```vb
Private Sub btnCalculate_Click(sender As Object, e As EventArgs) Handles btnCalculate.Click
Dim num1 As Double = CDbl(txtNum1.Text)
Dim num2 As Double = CDbl(txtNum2.Text)
Dim operator As String = cmbOperator.SelectedItem.ToString()
Dim result As Double
Select Case operator
Case "+"
result = num1 + num2
Case "-"
result = num1 - num2
Case "*"
result = num1 * num2
Case "/"
result = num1 / num2
End Select
lblResult.Text = "Result: " & result.ToString()
End Sub
```
练习题二：学生成绩管理系统
编写一个VB程序，实现一个简单的学生成绩管理系统。

要求用户输入学生的姓名和成绩，然后将其保存到数组中。

用户可以通过输入姓名来查询学生的成绩。

解答：
```vb
Private Structure Student
Public Name As String
Public Score As Double
End Structure
Private students() As Student
Private Sub btnAdd_Click(sender As Object, e As EventArgs) Handles btnAdd.Click
Dim newStudent As Student
= txtName.Text
newStudent.Score = CDbl(txtScore.Text)
ReDim Preserve students(students.Length)
students(students.Length - 1) = newStudent
txtName.Text = ""
txtScore.Text = ""
End Sub
Private Sub btnSearch_Click(sender As Object, e As EventArgs) Handles btnSearch.Click
Dim searchName As String = txtSearchName.Text
Dim found As Boolean = False
For Each student As Student In students
If = searchName Then
lblSearchResult.Text = "Score: " & student.Score.ToString()
found = True
Exit For
End If
Next
If Not found Then
lblSearchResult.Text = "Student not found."
End If
End Sub
```
练习题三：简单的文本编辑器
编写一个VB程序，实现一个简单的文本编辑器功能。

用户可以打开一个文本文件，编辑其中的内容，并保存修改后的文件。

解答：
```vb
Private Sub btnOpen_Click(sender As Object, e As EventArgs) Handles btnOpen.Click
Dim openFileDialog As New OpenFileDialog()
openFileDialog.Filter = "Text Files (*.txt)|*.txt"
If openFileDialog.ShowDialog() = DialogResult.OK Then
Dim fileContent As String =
puter.FileSystem.ReadAllText(openFileDialog.FileName)
txtEditor.Text = fileContent
End If
End Sub
Private Sub btnSave_Click(sender As Object, e As EventArgs) Handles btnSave.Click
Dim saveFileDialog As New SaveFileDialog()
saveFileDialog.Filter = "Text Files (*.txt)|*.txt"
If saveFileDialog.ShowDialog() = DialogResult.OK Then
puter.FileSystem.WriteAllText(saveFileDialog.FileName, txtEditor.Text, False)
End If
End Sub
```
以上是几个简单的VB练习题及其答案。

通过完成这些练习题，相信大家能够更好地理解和掌握VB编程的基础知识。

当然，编程是一个不断学习和实践的过程，希望大家能够持续努力，不断提升自己的编程能力。

祝愿大家在VB编程的道路上取得更大的成就！。