Question

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;

public partial class expt2 : System.Web.UI.Page
{
    double result ;
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
            result = 0.0;
 protected void Chkbxbd_CheckedChanged(object sender, EventArgs e)
    {
        if (Chkbxbd.Checked)
        {
            txtbxttl.Text = "" + 10000;
            result += double.Parse(txtbxttl.Text);

        }
        else
            result = result - 10000;


      }
    protected void Chkbxsfa_CheckedChanged(object sender, EventArgs e)
    {
        if (Chkbxsfa.Checked)
        {
            txtbxttl.Text = "" + 15000;
            result += double.Parse(txtbxttl.Text);

        }
        else
            result = result - 15000;


    }
 protected void btnttl_Click(object sender, EventArgs e)
    {
        txtbxttl.Text = "" + result;

    }
}

在此代码中，复选框的单个值是正常的，但是当总数达到时，它变为0。

请帮我解决。

Answer 1

“结果”值不会通过回发持续存在。当您需要最终结果或将其存储在视图状态时，可以重新计算它。

Answer 2

结果变量不会保留在众多的回发中，因为Web应用程序的性质是状态较少，因此会导致ViewState或Session变量的结果如下所示。

    public partial class expt2 : System.Web.UI.Page
{
    double result ;
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
              Session["result"] = 0.0;
    }
 protected void Chkbxbd_CheckedChanged(object sender, EventArgs e)
    {
        if (Chkbxbd.Checked)
        {
            txtbxttl.Text = "" + 10000;

            result = double.Parse(Session["result"].ToString());
            result += double.Parse(txtbxttl.Text);

            Session["result"] = result;

        }
        else
        {
             result = double.Parse(Session["result"].ToString());
             result = result - 10000;
             Session["result"]= result;
        }



      }
    protected void Chkbxsfa_CheckedChanged(object sender, EventArgs e)
    {
        if (Chkbxsfa.Checked)
        {
            txtbxttl.Text = "" + 15000;
            result = double.Parse(Session["result"].ToString());
            result += double.Parse(txtbxttl.Text);
            Session["result"] = result;

        }
        else
        {
            result = double.Parse(Session["result"].ToString());
            result = result - 15000;
            Session["result"] = result;
        }



    }
 protected void btnttl_Click(object sender, EventArgs e)
    {
        txtbxttl.Text = "" + Session["result"].ToString();

    }
}

C＃：值不会在回发中持续存在

2 个答案: