真分页改进

Imports System.Data.SqlClient

Partial Class _Default
    Inherits System.Web.UI.Page


    Private pagesize As Integer = 3

    Private Function getPageCount() As Integer
        Using con As SqlConnection = New SqlConnection("Data Source=.;Initial Catalog=master;User ID=sa;Password=Abcdefg1")
            con.Open()
            Using cmd As SqlCommand = New SqlCommand("select count(*) from t_user", con)
                Return Math.Ceiling(cmd.ExecuteScalar() / pagesize)
            End Using
        End Using
    End Function

    Private Sub BindData()
        Using con As SqlConnection = New SqlConnection("Data Source=.;Initial Catalog=master;User ID=sa;Password=Abcdefg1")
            Using cmd As SqlCommand = New SqlCommand("select * from (select row_number() over(order by username desc) as rid,* from t_user) as t where rid between @s and @e", con)
                con.Open()
                cmd.Parameters.AddWithValue("s", (Me.Label1.Text - 1) * pagesize + 1)
                cmd.Parameters.AddWithValue("e", Me.Label1.Text * pagesize)
                Using sdr As SqlDataReader = cmd.ExecuteReader()
                    Me.Repeater1.DataSource = sdr
                    Me.Repeater1.DataBind()
                End Using
            End Using
        End Using
    End Sub

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        If Not IsPostBack Then
            Me.Label1.Text = 1
            Me.Label2.Text = getPageCount()
            Me.BindData()
        End If
    End Sub

    Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Me.Label1.Text = 1
        Me.BindData()
    End Sub

    Protected Sub Button2_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button2.Click
        If Label1.Text > 1 Then
            Label1.Text -= 1
        End If
        Me.BindData()
    End Sub

    Protected Sub Button3_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button3.Click
        If Label1.Text + 0 < Label2.Text Then
            Label1.Text += 1
        End If
        Me.BindData()
    End Sub

    Protected Sub Button4_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button4.Click
        Me.Label1.Text = Me.getPageCount()
        Me.BindData()
    End Sub

    Protected Sub Button5_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button5.Click
        If Me.TextBox3.Text >= 1 AndAlso Me.TextBox3.Text <= getPageCount() Then
            Me.Label1.Text = Me.TextBox3.Text
        End If
        Me.BindData()
    End Sub

    Protected Sub Repeater1_ItemCommand(ByVal source As Object, ByVal e As System.Web.UI.WebControls.RepeaterCommandEventArgs) Handles Repeater1.ItemCommand
        Dim s As String = e.CommandName
        If s.Equals("delete") Then
            Response.Write("de")
        ElseIf s.Equals("update") Then
            Response.Write("up")
        End If
    End Sub
End Class