Why does this error occur? Input string was not in a correct format in c #?

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Why does this error occur? Input string was not in a correct format in c #?

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#1 by (1 votes)

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Good morning: Peace with everyone ...

Error Searching in textbox is not controlled FromException, Input string was not in a correct format.

the folio is numeric type, when searching in my textbox if it does, but when you remove everything you write in the textbox, you mark that error, could someone tell me a solution ???

private void txtBusqueda_TextChanged(object sender, System.EventArgs e){
        if ((txtBusqueda.Text) != null){
            conexSQL.Open();
            SqlCommand cmd = new SqlCommand("select * from _producto where folio=@folio", conexSQL);

            cmd.Parameters.Add("@folio",  SqlDbType.Int).Value = Convert.ToInt32 (txtBusqueda.Text);
            SqlDataReader dr = cmd.ExecuteReader();
            if (dr.Read()){
                cmbNom.Text = dr["nombre"].ToString();
                cmbDes.Text = dr["descripcion"].ToString();
            }
            else{

            }
            dr.Close();
            conexSQL.Close();
        }
      }

c# sql-server visual-studio-2010

asked by AraceLi Torres 23.09.2016 в 16:29

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1 answer

Better or more efficient practice in php error: Object reference not set to an instance of an object. Genexus ev1

score 1 · Accepted Answer

It may be that the TextBox is not null in its content, so enter in the if

the right thing would be

if (!string.IsNullOrEmpty(txtBusqueda.Text)){ ...

You could also use

int busqueda = 0;

if(int.TryParse(txtBusqueda.Text, out busqueda)){

    //si ingresa es un valor nro valido

}

Of course you would use the variable busqueda in the parameter of the query