05-10-16 Substring

namespace _05_10_16_SubString



{
  public partial class frm_substring : Form



{
  public frm_substring()



{

InitializeComponent();

}
  private void btnProcurar_Click(object sender, EventArgs e)



{
  int i, qtd;

string aux;



qtd = 0;

aux = txtFrase.Text;

aux = aux.ToUpper();
  for ( i = 0; i < aux.Length; i++)




  if (aux.Substring(i, 1) == txtLetra.Text.ToUpper())



{

qtd++;

}
  MessageBox.Show("A letra aparece " + Convert.ToString(qtd) + " vezes.");





}
  private void btnLimpar_Click(object sender, EventArgs e)



{
  txtLetra.Text = "";

txtFrase.Text = "";



}
  private void Sair_Click(object sender, EventArgs e)



{
  this.Close();



}

}

}