当前位置: 首页 > 图文教程 > 网络编程 > ASP > 大数量查询分页显示 微软的解决办法

ASP
构建你的网站新闻自动发布系统之三
构建你的网站新闻自动发布系统之四
如何用ASP编写网站统计系统一
如何用ASP编写网站统计系统二
如何用ASP编写网站统计系统三
如何用ASP编写网站统计系统四
ASP Error 0115的一些解决办法
ASP 3.0 新特色先睹为快(一)
ASP 3.0 新特色先睹为快(二)
ASP主件中的安全问题
一个汉字转成拼音的代码
使用w3Sockets组件实现域名查询功能
ASP中实现文件上传方法的研究
构建免受FSO组件威胁虚拟主机
用XMLHTTP做一个自己特色的Google
用asp实现的代码批量修改程序
无组件的数据库的备份与还原
用ASPJPEG组件制作图片的缩略图和加水印
解密ASP源代码
XmlHttp异步获取网站数据的例子

ASP 中的 大数量查询分页显示 微软的解决办法


出处:互联网   整理: 软晨网(RuanChen.com)   发布: 2009-09-13   浏览: 163 ::
收藏到网摘: n/a

微软的解决办法
using System;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Windows.Forms;
public class PagingSample: Form
{
// Form controls.
Button prevBtn = new Button();
Button nextBtn = new Button();
static DataGrid myGrid = new DataGrid();
static Label pageLbl = new Label();
// Paging variables.
static int pageSize = 10; // Size of viewed page.
static int totalPages = 0; // Total pages.
static int currentPage = 0; // Current page.
static string firstVisibleCustomer = ""; // First customer on page to determine location for move previous.
static string lastVisibleCustomer = ""; // Last customer on page to determine location for move next.
// DataSet to bind to DataGrid.
static DataTable custTable;
// Initialize connection to database and DataAdapter.
static SqlConnection nwindConn = new SqlConnection("Data Source=localhost;Integrated Security=SSPI;Initial Catalog=northwind");
static SqlDataAdapter custDA = new SqlDataAdapter("", nwindConn);
static SqlCommand selCmd = custDA.SelectCommand;
public static void GetData(string direction)
{
// Create SQL statement to return a page of records.
selCmd.Parameters.Clear();
switch (direction)
{
case "Next":
selCmd.CommandText = "SELECT TOP " + pageSize + " CustomerID, CompanyName FROM Customers " +
"WHERE CustomerID > @CustomerId ORDER BY CustomerID";
selCmd.Parameters.Add("@CustomerId", SqlDbType.VarChar, 5).Value = lastVisibleCustomer;
break;
case "Previous":
selCmd.CommandText = "SELECT TOP " + pageSize + " CustomerID, CompanyName FROM Customers " +
"WHERE CustomerID < @CustomerId ORDER BY CustomerID DESC";
selCmd.Parameters.Add("@CustomerId", SqlDbType.VarChar, 5).Value = firstVisibleCustomer;
break;
default:
selCmd.CommandText = "SELECT TOP " + pageSize + " CustomerID, CompanyName FROM Customers ORDER BY CustomerID";
// Determine total pages.
SqlCommand totCMD = new SqlCommand("SELECT Count(*) FROM Customers", nwindConn);
nwindConn.Open();
int totalRecords = (int)totCMD.ExecuteScalar();
nwindConn.Close();
totalPages = (int)Math.Ceiling((double)totalRecords / pageSize);
break;
}
// Fill a temporary table with query results.
DataTable tmpTable = new DataTable("Customers");
int recordsAffected = custDA.Fill(tmpTable);
// If table does not exist, create it.
if (custTable == null)
custTable = tmpTable.Clone();
// Refresh table if at least one record returned.
if (recordsAffected > 0)
{
switch (direction)
{
case "Next":
currentPage++;
break;
case "Previous":
currentPage--;
break;
default:
currentPage = 1;
break;
}
pageLbl.Text = "Page " + currentPage + " of " + totalPages;
// Clear rows and add new results.
custTable.Rows.Clear();
foreach (DataRow myRow in tmpTable.Rows)
custTable.ImportRow(myRow);
// Preserve first and last primary key values.
DataRow[] ordRows = custTable.Select("", "CustomerID ASC");
firstVisibleCustomer = ordRows[0][0].ToString();
lastVisibleCustomer = ordRows[custTable.Rows.Count - 1][0].ToString();
}
}

public PagingSample()
{
// Initialize controls and add to form.
this.ClientSize = new Size(360, 274);
this.Text = "NorthWind Data";
myGrid.Location = new Point(10,10);
myGrid.Size = new Size(340, 220);
myGrid.AllowSorting = true;
myGrid.CaptionText = "NorthWind Customers";
myGrid.ReadOnly = true;
myGrid.AllowNavigation = false;
myGrid.PreferredColumnWidth = 150;
prevBtn.Text = "<<";
prevBtn.Size = new Size(48, 24);
prevBtn.Location = new Point(92, 240);
prevBtn.Click += new EventHandler(Prev_OnClick);
nextBtn.Text = ">>";
nextBtn.Size = new Size(48, 24);
nextBtn.Location = new Point(160, 240);
pageLbl.Text = "No Records Returned.";
pageLbl.Size = new Size(130, 16);
pageLbl.Location = new Point(218, 244);
this.Controls.Add(myGrid);
this.Controls.Add(prevBtn);
this.Controls.Add(nextBtn);
this.Controls.Add(pageLbl);
nextBtn.Click += new EventHandler(Next_OnClick);

// Populate DataSet with first page of records and bind to grid.
GetData("Default");
DataView custDV = new DataView(custTable, "", "CustomerID", DataViewRowState.CurrentRows);
myGrid.SetDataBinding(custDV, "");
}

public static void Prev_OnClick(object sender, EventArgs args)
{
GetData("Previous");
}
public static void Next_OnClick(object sender, EventArgs args)
{
GetData("Next");
}
}

public class Sample
{
static void Main()
{
Application.Run(new PagingSample());
}
}