三、代码设计： Imports System.Data.SqlClient Public Class WebForm1 Inherits System.Web.UI.Page
Dim scon As New SqlConnection("server=localhost;database=northwind;uid=sa;pwd=123") Dim sDA As SqlDataAdapter Dim ds As DataSet Dim currentPage As Integer '记录着目前在哪一页上 Dim maxPage As Integer '总共有多少页 Const rowCount As Integer = 3 '一页有多少行 Dim rowSum As Integer '总共有多少行
'窗体代码省略
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
If Not Page.IsPostBack Then sDA = New SqlDataAdapter("select employeeid, lastname from employees order by employeeid", scon) ds = New DataSet Try sDA.Fill(ds, "employees") '获取总共有多少行 rowSum = ds.Tables(0).Rows.Count Catch ex As Exception rowSum = 0 End Try
'如果没有数据，退出过程 If rowSum = 0 Then Exit Sub '计算出浏览数据的总页数 If rowSum Mod rowCount ＞ 0 Then '有余数要加1 maxPage = rowSum \ rowCount + 1 Else '正好除尽 maxPage = rowSum \ rowCount End If
currentPage = 1 '调用绑定数据过程 readpage(currentPage) BindData() Label2.Text = maxPage '首页和上一页按钮不可见 Button1.Visible = False Button2.Visible = False End If End Sub
'创建一个绑定数据的过程 Sub BindData() Repeater1.DataSource = ds Repeater1.DataBind() Label1.Text = currentPage End Sub
'创建一个填充数据集的过程 Sub readpage(ByVal n As Integer) sDA = New SqlDataAdapter("select employeeid, lastname from employees order by employeeid", scon) ds = New DataSet ds.Clear() sDA.Fill(ds, (n - 1) * rowCount, rowCount, "employees") End Sub
'首页按钮 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
'上一页按钮 Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click '如果现在页是第二页，设置首页和上一页按钮不可见 If Label1.Text ＞ 2 Then Button3.Visible = True Button4.Visible = True Else Button1.Visible = False Button2.Visible = False Button3.Visible = True Button4.Visible = True End If currentPage = Label1.Text - 1 readpage(currentPage) BindData() End Sub
'下一页按钮 Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click '如果现在页倒数第二页，设置最后页和下一页按钮不可见 If Label1.Text ＜ Label2.Text - 1 Then Button1.Visible = True Button2.Visible = True Else Button1.Visible = True Button2.Visible = True Button3.Visible = False Button4.Visible = False End If currentPage = Label1.Text + 1 readpage(currentPage) BindData() End Sub
'尾页按钮 Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click '设置当前页为最大页数 currentPage = Label2.Text readpage(currentPage) BindData() Button1.Visible = True Button2.Visible = True Button3.Visible = False Button4.Visible = False End Sub End Class
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