Visual Basic Not programı yardim.

 
  Imports System.Collections.Generic 
  Imports System.Drawing 
  Imports System.Windows.Forms 
  Imports System.Linq 
   
  Public Partial Class MainForm 
  	Inherits Form 
  	Public Sub New() 
   
   
  		InitializeComponent() 
  	End Sub 
   
  	Private Shared Sub Yalnızsayı(sender As Object, e As KeyPressEventArgs) 
   
   
  		If Not Char.IsControl(e.KeyChar) AndAlso Not Char.IsDigit(e.KeyChar) AndAlso (e.KeyChar <> "."C) Then 
  			e.Handled = True 
  		End If 
   
  	End Sub 
   
  	Private Sub Button1Click(sender As Object, e As EventArgs) 
  		textBox3.Text = (Convert.ToDouble(textBox1.Text) * 0.2 + Convert.ToDouble(textBox2.Text) * 0.8).ToString() 
  	End Sub 
   
  	Private Sub MainFormLoad(sender As Object, e As EventArgs) 
  		For Each textBox As TextBox In Controls.OfType(Of TextBox)() 
  			AddHandler textBox.KeyPress, AddressOf Yalnızsayı 
  			AddHandler textBox.TextChanged, AddressOf sayı 
  		Next 
  	End Sub 
   
  	Private Sub sayı(sender As Object, e As EventArgs) 
   
  		For Each textBox As TextBox In Controls.OfType(Of TextBox)() 
   
  			If textBox.Text <> "" Then 
  				If Convert.ToDouble(textBox.Text) > 100 Then 
   
  					textBox.Text = "100" 
  				End If 
   
  			End If 
  		Next 
  	End Sub 
   
  End Class