查询 开始时间 结束时间

Page_Load:
        If Not Page.IsPostBack Then

            '--------------------------下面的是错误的 如果2006-10-31 那么-1月 就是 2006-9-31 所以是错误的
            Dim year, month, day As Integer
            day = Now.Day
            If Now.Month >= 2 Then
                month = Now.Month - 1
                year = Now.Year
            Else
                month = 12
                year = Now.Year - 1
            End If

            Dim dt As Date = New Date(year, month, day)

            Me.txt_BDate.Value = Format(dt, "yyyy\/MM\/dd")
            '---------------------------------------------------------------------------
            Me.txt_BDate.Value = Format(Now.AddMonth(-1),"yyyy\/MM\/dd")
            Me.txt_EDate.Value = Format(Now, "yyyy\/MM\/dd")
        End If

'===============================================================

Bind_Data:
        Dim str_BDate As String = Me.txt_BDate.Value
        Dim str_EDate As String = Me.txt_EDate.Value
        str_EDate = CDate(str_EDate).AddDays(1).ToString("yyyy/MM/dd")
......
......
If str_BDate <> "" Then
            str_sql += " and Send_Time>='" + str_BDate + "' "
        End If
        If str_EDate <> "" Then
            str_sql += " and Send_Time<='" + str_EDate + "' "
        End If
'===============================================================