用vb写一个求素数代码

以下是用 VB 编写的求素数代码：

Private Function IsPrime(ByVal num As Integer) As Boolean
If num <= 1 Then
Return False
End If
For i As Integer = 2 To Math.Sqrt(num)
If num Mod i = 0 Then
Return False
End If
Next
Return True
End Function

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim n As Integer = Integer.Parse(TextBox1.Text)
Dim primes As New List(Of Integer)
For i As Integer = 2 To n
If IsPrime(i) Then
primes.Add(i)
End If
Next
MessageBox.Show(String.Join(", ", primes))
End Sub

这个代码可以在一个文本框中输入一个整数 n，然后输出从 2 到 n 之间的所有素数。