主题：限制行数

帮你一下代码吧，如果要限制，要这样写。

Dim drs As List(Of DataRow)
Dim xj As WinForm.textBox = e.Form.Controls("姓名")

If xj.Text > "" Then
    Dim fdr As DataRow = DataTables("收购").find("[姓名] = '" & xj.Text & "' and [凭证号] is null")
    If fdr IsNot Nothing Then
        Dim Filter As String
        Filter =  "[姓名] = '" & xj.Text & "' and 凭证号 Is null And [重量] <> 0 And [日期] = #" & vars("adate") & "#"
        drs = Tables("打印收购窗口_Table1").DataTable.Select(filter)
        Dim idxs As String = ""
        Dim count As Integer = 0
        For count To drs.Count - 1
            If count = 5 Then
                Exit For
            End If
            idxs = drs(count)("_Identify") & ","
        Next
        Tables("打印收购窗口_Table1").filter = "_Identify in (" & idxs.trim(",") & ")"
    End If
End If

是的，你改一下

For count = 0 To drs.Count - 1

 代码写错了

Dim drs As List(Of DataRow)
Dim xj As WinForm.textBox = e.Form.Controls("姓名")

If xj.Text > "" Then
    Dim fdr As DataRow = DataTables("收购").find("[姓名] = '" & xj.Text & "' and [凭证号] is null")
    If fdr IsNot Nothing Then
        Dim Filter As String
        Filter =  "[姓名] = '" & xj.Text & "' and 凭证号 Is null And [重量] <> 0 And [日期] = #" & vars("adate") & "#"
        drs = Tables("打印收购窗口_Table1").DataTable.Select(filter)
        Dim idxs As String = ""
        For count As Integer = 0 To drs.Count - 1
            If count = 5 Then
                Exit For
            End If
            idxs = idxs & drs(count)("_Identify") & ","
        Next
        Tables("打印收购窗口_Table1").filter = "_Identify in (" & idxs.trim(",") & ")"
    End If
End If

如下

Dim drs As List(Of DataRow)
Dim xj As WinForm.textBox = e.Form.Controls("姓名")

If xj.Text > "" Then
    Dim fdr As DataRow = DataTables("收购").find("[姓名] = '" & xj.Text & "' and [凭证号] is null")
    If fdr IsNot Nothing Then
        Dim Filter As String
        Filter =  "[姓名] = '" & xj.Text & "' and 凭证号 Is null And [重量] <> 0 And [日期] = #" & vars("adate") & "#"
        drs = Tables("打印收购窗口_Table1").DataTable.Select(filter)
        Dim idxs As String = ""
        Dim djs As new List(of String)
        For count As Integer = 0 To drs.Count - 1
            If djs.Contains(drs(count)("单价")) = False Then
                djs.add(drs(count)("单价"))
                idxs = idxs & "'" & drs(count)("单价") & "',"         
                If djs.count = 5 Then
                    Exit For
                End If
            End If
        Next
        Tables("打印收购窗口_Table1").filter = "单价 in (" & idxs.trim(",") & ")"
    End If
End If