小编kan*_*nan的帖子

我是asp.net的新手.我写了一页asp.net,但是当我运行它时,我得到以下错误.

 public partial class Issueofbook: System.Web.UI.Page
 {
public Int64 Sid;
protected void Page_Load(object sender, EventArgs e)
{
    string Id;
    Id = Request.QueryString.Get(0);

    if (!(IsPostBack == true))
    {
        if (Request.QueryString.Get(1) == "G")
        {
            Sid = Convert.ToInt64(Id);
            if (PopulatedRecord (Sid ) == false)
            {

            }
        }
     }
 }
 private Boolean PopulatedRecord(Int64 Id)
   {
    DataSet DS;
    DS = new DataSet();
    SqlCommand cmd = new SqlCommand();
    SqlDataAdapter da = new SqlDataAdapter();
    SqlConnection Cnn = new SqlConnection();
    string connectionstring;
    connectionstring = @"Datasource=DEVI\SQLEXPRESS;Intial catalog=librarymanagement;Integrated Security=SSPI";
    Cnn.ConnectionString …

我正在设计我的网页,因为我输入了书籍ID并输入了Nameofthebook.然后单击该书的堆栈可用的按钮是转到另一页然后不可用显示错误消息是书不可用我的项目(库管理系统)

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.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Data.SqlClient;

public partial class Bookcheck : System.Web.UI.Page
{

    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        string constr = null;
        constr = ConfigurationManager.ConnectionStrings["librarymanagementconnetionstring"].ConnectionString;
        SqlConnection cnn = new SqlConnection(constr);
        cnn.Open();
        DataSet ds = new DataSet();
        DataTable dt = new DataTable();
        SqlDataAdapter da = new SqlDataAdapter("SELECT*FROM BOOKREGISTRATIONDETAILS WHERE bookId='" …