This document contains Visual Basic code to calculate a person's body mass index (BMI) based on their weight and height. The code takes weight and height values entered into text boxes, calculates the BMI, displays the result, and classifies the BMI into categories like underweight, normal, overweight, obese type I, obese type II, or obese type III. It also contains validation to check for valid weight and height ranges. The reset button clears all values and text labels for a new calculation.

1. Índice De masa Corporal
Formulario Principal
Ahora ingresaremos un peso (KG) y talla (M) será:

2. Ahora mostraremos el código en visual basic:
Public Class Form1
Dim Imc As Double
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Imc = Val(Peso.Text) / (Val(Altura.Text) * Val(Altura.Text))
Label3.Text = Format(Imc, "##.##")
Label3.Visible = True
Button2.Enabled = True
Select Case Imc
Case Is < 17
Label4.Text = "Delgadez severa."
Label4.Visible = True
Case 17 To 18.49
Label4.Text = "Delgadez aceptable."
Label4.Visible = True
Case 18.5 To 24.99
Label4.Text = "Peso normal."
Label4.Visible = True
Case 25 To 29.99
Label4.Text = "Sobrepeso."
Label4.Visible = True
Case 30 To 34.99
Label4.Text = "Obeso: Tipo I."
Label4.Visible = True
Case 35 To 39.99
Label4.Text = "Obeso: Tipo II."
Label4.Visible = True
Case 40 To 60
Label4.Text = "Obeso: Tipo III."
Label4.Visible = True
End Select
End Sub
Private Sub TextBox1_KeyPress(ByVal KeyAscii As Integer)
If KeyAscii = Asc(vbCr) Then
If Val(Peso.Text) < 40 Or Val(Altura.Text) > 200 Then
MsgBox("Valor de PESO erróneo. Será corregido.")
Peso.Text = 60
End If
End If
End Sub
Private Sub TextBox1_LostFocus(ByVal sender As Object, ByVal e As
System.EventArgs) Handles Peso.LostFocus
TextBox1_KeyPress(Asc(vbCr))
End Sub

3. Private Sub TextBox2_KeyPress(ByVal KeyAscii As Integer)
If KeyAscii = Asc(vbCr) Then
If Val(Altura.Text) < 1.4 Or Val(Altura.Text) > 2.1 Then
MsgBox("Valor de la TALLA errónea. Será corregida.")
Altura.Text = 1.65
End If
End If
End Sub
Private Sub TextBox2_LostFocus(ByVal sender As Object, ByVal e As
System.EventArgs) Handles Altura.LostFocus
TextBox2_KeyPress(Asc(vbCr))
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button2.Click
Peso.Text = ""
Altura.Text = ""
Label3.Visible = False
Label4.Visible = False
Peso.Focus()
Button2.Enabled = False
End Sub
End Class