主题：打印后台数据

 

Dim doc As New PrintDoc
Dim rt As New prt.RenderTable
Dim cmd As New SQLCommand '定义一个SQL命令
Dim dt As DataTable '定义一个数据表变量
Dim Count As Integer = 0
cmd.CommandText = "Select * From {订单} Where Year(日期) = 2009 And Month(日期) = 6"
dt = cmd.ExecuteReader() '生成一个临时表
For Each Col AS DataCol In Dt.DataCols
    rt.Cells(0,Count).Text = Col.Name
    For r As integer = 0 To dt.DataRows.Count - 1
        rt.Cells(r +1,Count).Text = dt.DataRows(r)(Col.Name)
    Next
    Count = Count + 1
Next
rt.Style.Gridlines.All = New prt.Linedef(Color.Gray) '灰色网格线
rt.CellStyle.Spacing.All = 1 '内容距离网格线1毫米
rt.Rows(0).Style.TextAlignHorz = prt.AlignHorzEnum.Center '第一行内容水平居中
doc.Body.Children.Add(rt)
doc.Preview()

 

日期列为空，打印显示为0：00：00

如何使打印显示也为空呢？

都会打印后台数据了，加个判断应该不难吧：

IsNull

判断某一列的内容是否为空。

例如：

If DataTables("订单").DataRows(0).IsNull("日期") Then
    MessageBox.Show("错误，第一行没有输入日期！")
End If

Dim doc As New PrintDoc
Dim rt As New prt.RenderTable
Dim cmd As New SQLCommand '定义一个SQL命令
Dim dt As DataTable '定义一个数据表变量
Dim Count As Integer = 0
cmd.CommandText = "Select * From {订单} Where Year(日期) = 2009 And Month(日期) = 6"
dt = cmd.ExecuteReader() '生成一个临时表
For Each Col As DataCol In Dt.DataCols
    rt.Cells(0,Count).Text = Col.Name
    For r As Integer = 0 To dt.DataRows.Count - 1
        If dt.DataRows(i).IsNull(Col.Name) Then
            rt.Cells(r +1,Count).Text = ""
        Else
            rt.Cells(r +1,Count).Text = dt.DataRows(r)(Col.Name)
        End If
    Next
    Count = Count + 1
Next
rt.Style.Gridlines.All = New prt.Linedef(Color.Gray) '灰色网格线
rt.CellStyle.Spacing.All = 1 '内容距离网格线1毫米
rt.Rows(0).Style.TextAlignHorz = prt.AlignHorzEnum.Center '第一行内容水平居中
doc.Body.Children.Add(rt)
doc.Preview()

此主题相关图片如下：1471.png

If dt.DataRows(r).IsNull(Col.Name) Then

晕!