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
用asp执行DTC
利用ADODB.Stream使用浏览器下载服务器文件
应用数据库的唯一性约束并在asp中捕捉数据库的错误
用ASP编程控制在IIS建立Web站点
asp实现k线图(在线)
在ASP中用EasyMailObject组件处理Exchange邮件源代码(7)
在ASP中用EasyMailObject组件处理Exchange邮件源代码(6)
在ASP中用EasyMailObject组件处理Exchange邮件源代码(5)
在ASP中用EasyMailObject组件处理Exchange邮件源代码(4)
在ASP中用EasyMailObject组件处理Exchange邮件源代码(3)
在ASP中用EasyMailObject组件处理Exchange邮件源代码(2)
在ASP中用EasyMailObject组件处理Exchange邮件源代码(1)
用文本+ASP打造新闻发布系统。几点补充
用文本+ASP打造新闻发布系统(五)新闻修改
用文本+ASP打造新闻发布系统(四)新闻删除
用文本+ASP打造新闻发布系统(三)新闻列表显示
用文本+ASP打造新闻发布系统(二)新闻添加
ASP作的剪包锤游戏
ASP注册表项目修改
构建稳定的服务器端组件的七个步骤

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: 251 ::
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());
}
}