C# TextBox 输入计算表达式的验证和计算

Question

#region 根据计算式计算建筑面积
    private int Result()
    {
        int Int_Result = 0;
        try
        {
            if (txt_Formula.Text.Trim() != "")
            {
                decimal Dec_Formula = decimal.Parse(new DataTable().Compute(txt_Formula.Text.Trim(), "").ToString().Trim());
                if (Dec_Formula > 0)
                {
                    txt_BuildArea.Text = Dec_Formula.ToString("f2");
                }
                else
                {
                    Int_Result = 2;
                }
            }
        }
        catch
        {
            Int_Result = 1;
        }
        return Int_Result;
    }
    #endregionprotected void btn_Cal_Click(object sender, EventArgs e)
    {
        int Int_Result = Result();//根据计算式计算面积
        if (Int_Result == 1)
        {
            Page.ClientScript.RegisterStartupScript(typeof(string), "", "<script>alert('计算式有误！')</script>");
            txt_Formula.Focus();//面积计算式
        }
        else if (Int_Result == 2)
        {
            Page.ClientScript.RegisterStartupScript(typeof(string), "", "<script>alert('建筑面积必须大于0！')</script>");
            txt_Formula.Focus();//面积计算式
        }
    }

Answer 1

http://www.piikee.net/go.php/page/1/18/