会话和视图状态转换为 asp 标签答案

【问题标题】：Session and View state into asp labels会话和视图状态转换为 asp 标签
【发布时间】：2014-07-29 15:17:20
【问题描述】：

我一直在努力让视图状态在一个简单的网站上工作。我才刚刚开始学习 ASP，并且在尝试研究实现视图状态和会话的方法时感到困惑。我希望能够在文本框中输入文本并更改视图状态和会话。我已经成功地让会话在页面加载时更改和打印，但我不知道如何打印视图状态。我只是通过尝试查看其他示例来进一步混淆自己，并且我可以使用一些帮助来使我的视图状态和会话正常工作。

这是我的 .cs 文件：

using System;
using System.Collections.Generic;    
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class Public_Unit3Assignment : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
    //Top of page
    Response.Write("Session State: ");    //Shows what the current session data is
    Response.Write(Session["New"]);

    Response.Write("<br />");

    Response.Write("Veiwstate: ");          //Trying to show what current Viewstate `data is`
    Response.Write(ViewState["NameOfUser"]);



    Response.Write("<br />");

    if (!IsPostBack)
    {
        string str = "Sample ViewState";
        if (ViewState["NameOfUser"] == null)
        {
            ViewState["NameOfUser"] = str;
        }

    }
}

//onlcick to display Viewstate
protected void SubmitForm_Click(object sender, EventArgs e)
{
    Label2.Text = ViewState["NameOfUser"].ToString();
    ViewState["NameOfUser"] = TextBox1.Text;   //Try to fill viewstate with text from textbox1
    lbl1.Text = TextBox1.Text;
    Label2.Text = TextBox1.Text;
}

//Onlcick event to display session
protected void SubmitForm_Click2(object sender, EventArgs e)
{
    Session["New"] = SessionTextBox.Text;
    Sessionexample.Text = Session["New"].ToString();  //Trying to enter session data into label 
    Sessionexample.Text = SessionTextBox.Text;        //Trying to enter session data into label 
    SessionResult.Text = SessionTextBox.Text;         //Trying to enter session data into label 

}

这是我的 .aspx 文件：

<%@ Page Title="" Language="C#" MasterPageFile="~/MasterPages/Assignment.master" AutoEventWireup="true" CodeFile="Unit3Assignment.aspx.cs" Inherits="Public_Unit3Assignment" %>

<asp:Content ID="Content1" ContentPlaceHolderID="HeadContentPlaceholder" Runat="Server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="BodyContentPlaceholder" Runat="Server">

    <div class="Content">


        <asp:ScriptManager ID="ScriptManager1" runat="server" />


        <br /><br />


        <asp:UpdatePanel
            id="up1"
            runat="server">
            <ContentTemplate>

                <br />


                <br />

            <asp:Label
                id="lbl1"
                text="ViewState Example"
                runat="server"></asp:Label>

                <br />

                <asp:TextBox
                    id="TextBox1"
                    Text="ViewState Example TextBox"
                    runat="Server" />

                <br />

            <asp:Label
                id="Label2"
                text="ViewState Result"
                runat="server"></asp:Label>
                <br />

                <asp:TextBox
                    id="TextBox2"
                    Text="ViewState Result TextBox"
                    ReadOnly="true"
                    runat="Server" />

                <br />

                <asp:Button
                    runat="server"
                    onclick="SubmitForm_Click"
                    text="Submit & set name" />

            </ContentTemplate>
        </asp:UpdatePanel>





        </div>

    <asp:UpdatePanel
        id="up2"
        runat="server">

       <ContentTemplate>

           <asp:Label
               id="Sessionexample"
               text="Session Example"
               runat="server" />

           <br />
           <asp:TextBox
               id="SessionTextBox"
               text="SessionTextBox"
               runat="server" />
           <br />

           <asp:Label
               id="SessionResult"
               text="Session Result"
               runat="server" />
           <br />
           <asp:TextBox
               id="SessionResultTextBox"
               text="SessionResultTextBox"
               readonly="true"
               runat="server" />

           <br />
        <asp:Button
            id="btn2"
            runat="server"
            onclick="SubmitForm_Click2"
            text="Submit for Session"/>

           <br />
       </ContentTemplate>


    </asp:UpdatePanel>
</asp:Content>

任何帮助将不胜感激。谢谢

【问题讨论】：

viewstate，不要乱来，asp.net用它来存储控制状态，sesssion状态是用来判断当前会话是否有效，认为你可能会混淆它与会话变量或查询字符串，这两个都可以用来保存会话数据，它总是临时的。
您应该避免在页面上下文中使用Response.Write，因为它会将结果写入文件的末尾（或开头，不记得是哪个）。相反，将文本附加到占位符或其他控件。

标签： c# asp.net session viewstate

【解决方案1】：

这很尴尬，因为我认为我的问题不够具体，但我通过查看 microsoft.com 上的示例回答了我自己的问题。很难解释我在这里试图用 Session 做什么和查看状态，但本质上我需要将会话数据从输入和 onclick 事件放入文本框中。我的问题源于不知道如何使用：if (IsPostBack)。我还是 ASP 和 C# 的新手。也感谢您的回复，我确实需要对该主题进行一些阅读。无论如何，这是我想要创建的代码： .cs 文件：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        //session set
        Session["message"] = "Hello World";
        //session get
        lblMessage.Text = Session["message"].ToString();

        //viewstate set
        ViewState["message"] = "Hi there world";
        //viewstate get
        lblMessageView.Text = ViewState["message"].ToString();


    }

    protected void SubmitForm_Click(object sender, EventArgs e)
    {
        if (IsPostBack)
        {
            ViewState["New"] = TextView1.Text;         //makes new viewstate with text result
            TextView2.Text = ViewState["New"].ToString(); //Trying to enter viewstate data in text box
        }

    }

    protected void SubmitForm_Click2(object sender, EventArgs e)
    {
        if (IsPostBack)
        {
            Session["New"] = SessionTextBox.Text; //makes new session with text result
            SessionResultTextBox.Text = Session["New"].ToString();  //Trying to enter session data into text box
        }

    }



}

.aspx 文件：

<%@ Page Title="" Language="C#" MasterPageFile="~/MasterPages/Assignment.master" AutoEventWireup="true" CodeFile="Unit3Assignment.aspx.cs" Inherits="Public_Unit3Assignment" %>

<asp:Content ID="Content1" ContentPlaceHolderID="HeadContentPlaceholder" Runat="Server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="BodyContentPlaceholder" Runat="Server">



    <asp:Label
        id="session"
        runat="server"
        text="Session Message: " />

<asp:Label
    id="lblMessage"
    runat="server" 
    backcolor="Yellow"
    forecolor="Black" />

    <br />

    <asp:Label
        id="viewstate"
        runat="server"
        text="ViewState Message: " />

<asp:Label
    id="lblMessageView"
    runat="server" 
    backcolor="red"
    forecolor="green" />

<br /><br /><br />

    <asp:ScriptManager ID="ScriptManager1" runat="server" />
    <asp:UpdatePanel
        id="up1"
        runat="server" >

    <ContentTemplate>
        <br />

    <asp:Label
        id="View1"
        text="ViewState Example"
        runat="server" />

        <br />

        <asp:TextBox
            id="TextView1"
            text="ViewStateTextBox"
            runat="server" />

        <br />

       <asp:Label
        id="View2"
        text="ViewState Result"
        runat="server" />

        <br />

         <asp:TextBox
            id="TextView2"
            text="ViewStateResultTextBox"
            runat="server" />

        <br />

        <asp:Button
            id="btn1"
            runat="server"
            onclick="SubmitForm_Click" 
            text="Show ViewState"/>

        </ContentTemplate>

        </asp:UpdatePanel>

    <br /><br /><br />

        <asp:UpdatePanel
        id="up2"
        runat="server">

       <ContentTemplate>

           <asp:Label
               id="Sessionexample"
               text="Session Example"
               runat="server" />

           <br />
           <asp:TextBox
               id="SessionTextBox"
               text="SessionTextBox"
               runat="server" />
           <br />

           <asp:Label
               id="SessionResult"
               text="Session Result"
               runat="server" />
           <br />
           <asp:TextBox
               id="SessionResultTextBox"
               text="SessionResultTextBox"
               readonly="true"
               runat="server" />

           <br />
        <asp:Button
            id="btn2"
            runat="server"
            onclick="SubmitForm_Click2"
            text="Submit for Session"/>

           <br />
       </ContentTemplate>


    </asp:UpdatePanel>



</asp:Content>

【讨论】：