Question

我有一个运行查询的VB.net程序，填充数据集并将信息放入表中。然后我发电子邮件给这张桌该程序有效，但是如果数据集没有返回任何结果，我希望表格填充不同的信息。我目前的代码是：

Try
    Me.fTimeCardTableAdapter.Fill(Me.timecard.fTimeCard, "1/9/14", "1/10/14")
Catch ex As Exception
End Try

Dim Time1 = _
    <html>
      <body>
        <table border="1">
          <tr><th>First Name</th><th>Last Name</th><th>Total Hours</th><th>Break Time</th></tr>
            <%= From Time1break In Me.timecard.fTimeCard.AsEnumerable _
                    Select <tr><td><%= Time1break.sFirstName %></td>
                               <td><%= time1break.sLastName %>
                               </td><td><%= time1.TotalHours %></td>
                               <td><%= time1break.BreakTime %></td></tr> %>
        </table>
      </body>
    </html>

如果数据集为空，我希望它以这种方式填充表格：

<html>
  <body>
    <table border="1">
      <tr><th>No Exceptions found</th></tr>
    </table>
  </body>
</html>

我试过这个：

Try
    Me.fTimeCardTableAdapter.Fill(Me.timecard.fTimeCard, "1/9/14", "1/10/14")
Catch ex As Exception
End Try

If (Me.timecard.fTimeCard.Count = 0) Then GoTo Line1 Else GoTo Line2

Line1:  Dim Time1 = _
            <html>
              <body>
                <table border="0">
                  <tr><th>No Break Exceptions For Yesterday</th></tr>
                </table>
              </body>
            </html>

Line2:
        Time1 = _
          <html>
            <body>
              <table border="1">
                <tr><th>First Name</th><th>Last Name</th><th>Total Hours</th><th>Break Time</th></tr>
                <%= From time1break In Me.timecard.fTimeCard.AsEnumerable _
                        Select <tr><td><%= Time1break.sFirstName %></td>
                                   <td><%= Time1break.sLastName %>
                                   </td><td><%= time1break.TotalHours %></td>
                                   <td><%= time1break.BreakTime %></td></tr> %>
              </table>
            </body>
          </html>

但是，当数据集为空时，它仍然显示“Line2”。

Answer 1

以这种方式尝试：

 Dim Time1
 If Not Me.timecard Is Nothing AndAlso (Me.timecard.Table(fTimeCard).Rows.Count <> 0) Then 
    Time1 = _
      <html>
        <body>
          <table border="1">
            <tr><th>First Name</th><th>Last Name</th><th>Total Hours</th><th>Break Time</th></tr>
            <%= From time1break In Me.timecard.fTimeCard.AsEnumerable _
                    Select <tr><td><%= Time1break.sFirstName %></td>
                               <td><%= Time1break.sLastName %>
                               </td><td><%= time1break.TotalHours %></td>
                               <td><%= time1break.BreakTime %></td></tr> %>
          </table>
        </body>
      </html>
 Else
     Time1 = _
        <html>
          <body>
            <table border="0">
              <tr><th>No Break Exceptions For Yesterday</th></tr>
            </table>
          </body>
        </html>
 End If

如何将xelement指定为空

1 个答案: