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--  专家坐堂  (http://foxtable.com/bbs/list.asp?boardid=2)
----  关于预览图片问题  (http://foxtable.com/bbs/dispbbs.asp?boardid=2&id=154312)

--  作者：裴保民
--  发布时间：2020/9/10 18:04:00
--  关于预览图片问题

在 TimerTick 事件中写了如下代码，运行后假如数据行没有图片时会报错，怎么处理

Dim wjjmc As String
Dim t As Table = Tables("充值凭证表")
wjjmc =Format(T.Current("充值日期"),"yyy年MM月dd日") & "【" & T.Current("起始号") & "至" & T.Current("终止号") & "】"
Dim dlg As New FolderBrowserDialog
Dim czkh As DataRow
Dim shID As String = e.Form.Controls("czpzIDTextBox").value
Dim dr1 As DataRow = DataTables("充值凭证表").Find("充值凭证ID= \'" & shID & "\'" )
Dim str As String = dr1("充值凭证原始名称")
For Each file As String In FileSys.GetFiles(ProjectPath & "照片\\充值凭证截图\\" & wjjmc & "\\" )
Dim name As String = FileSys.GetName(file)
If name.Contains(str) Then
Dim ls = dr1.Lines("充值凭证")
If ls.contains(name) = False Then
ls.add(name)
dr1.lines("充值凭证") = ls
DataTables("充值凭证表").Save
End If
End If
Next
DataTables("充值凭证表").DataCols("充值凭证").DefaultFolder =ProjectPath & "照片\\充值凭证截图\\" & wjjmc & "\\"

此主题相关图片如下：截图08.jpg

此主题相关图片如下：截图09.jpg

[此贴子已经被作者于2020/9/10 19:39:24编辑过]

--  作者：有点蓝
--  发布时间：2020/9/10 20:21:00
--

……
Dim dr1 As DataRow = DataTables("充值凭证表").Find("充值凭证ID= \'" & shID & "\'" )
Dim str As String = dr1("充值凭证原始名称")
dim lst as list(of string)
if dr1.isnull("充值凭证") then
lst = new list(of string)
else
lst =dr1.Lines("充值凭证")
end if
For Each file As String In FileSys.GetFiles(ProjectPath & "照片\\充值凭证截图\\" & wjjmc & "\\" )
Dim name As String = FileSys.GetName(file)
If name.Contains(str) andalso lst.contains(name) = False  Then
  lst.add(name)
End If
Next
dr1.lines("充值凭证") = lst
DataTables("充值凭证表").Save
……

--  作者：裴保民
--  发布时间：2020/9/10 21:01:00
--
蓝老师照您修改后还是错误

此主题相关图片如下：截图10.jpg

此主题相关图片如下：截图11.jpg

代码如下

Dim wjjmc As String
Dim t As Table = Tables("充值凭证表")
wjjmc =Format(T.Current("充值日期"),"yyy年MM月dd日") & "【" & T.Current("起始号") & "至" & T.Current("终止号") & "】"
Dim dlg As New FolderBrowserDialog
Dim czkh As DataRow
Dim shID As String = e.Form.Controls("czpzIDTextBox").value
Dim dr1 As DataRow = DataTables("充值凭证表").Find("充值凭证ID= \'" & shID & "\'" )
Dim str As String = dr1("充值凭证原始名称")
Dim lst As List(of String)
If dr1.isnull("充值凭证") Then
lst = new List(of String)
Else
lst =dr1.Lines("充值凭证")
End If
For Each file As String In FileSys.GetFiles(ProjectPath & "照片\\充值凭证截图\\" & wjjmc & "\\" )
Dim name As String = FileSys.GetName(file)
If name.Contains(str) AndAlso lst.contains(name) = False Then
lst.add(name)
End If
Next
dr1.lines("充值凭证") = lst
DataTables("充值凭证表").Save
DataTables("充值凭证表").DataCols("充值凭证").DefaultFolder =ProjectPath & "照片\\充值凭证截图\\" & wjjmc & "\\"

[此贴子已经被作者于2020/9/10 21:12:50编辑过]

--  作者：有点蓝
--  发布时间：2020/9/10 21:45:00
--
提示的路径不存在

--  作者：裴保民
--  发布时间：2020/9/10 21:52:00
--
蓝老师是没照片，没照片这个文件夹肯定也不存在的，如果有照片行没事，只要某一行无照片就会出现错误，并且关闭了程序出现死循环
[此贴子已经被作者于2020/9/10 21:54:44编辑过]

--  作者：有点蓝
--  发布时间：2020/9/10 21:55:00
--
路径不存在，先判断一下http://www.foxtable.com/webhelp/topics/0334.htm

For Each file As String In FileSys.GetFiles(ProjectPath & "照片\\充值凭证截图\\" & wjjmc & "\\" )

--  作者：裴保民
--  发布时间：2020/9/10 22:16:00
--

Dim wjjmc As String
Dim t As Table = Tables("充值凭证表")
wjjmc =Format(T.Current("充值日期"),"yyy年MM月dd日") & "【" & T.Current("起始号") & "至" & T.Current("终止号") & "】"
Dim dlg As New FolderBrowserDialog
Dim czkh As DataRow
Dim shID As String = e.Form.Controls("czpzIDTextBox").value
Dim dr1 As DataRow = DataTables("充值凭证表").Find("充值凭证ID= \'" & shID & "\'" )
Dim str As String = dr1("充值凭证原始名称")
Dim lst As List(of String)
If dr1.isnull("充值凭证") Then
lst = new List(of String)
Else
lst =dr1.Lines("充值凭证")
End If
If FileSys.DirectoryExists(ProjectPath & "照片\\充值凭证截图\\" & wjjmc & "\\" ) Then \'如果目录C:\\MyFolder存在
For Each file As String In FileSys.GetFiles(ProjectPath & "照片\\充值凭证截图\\" & wjjmc & "\\" )
Dim name As String = FileSys.GetName(file)
If name.Contains(str) AndAlso lst.contains(name) = False Then
lst.add(name)
End If
Next
dr1.lines("充值凭证") = lst
DataTables("充值凭证表").Save
DataTables("充值凭证表").DataCols("充值凭证").DefaultFolder =ProjectPath & "照片\\充值凭证截图\\" & wjjmc & "\\"
End If

这段代码放到计时器上运行没发现错误，怎么放到CurrentChanged事件中就出现未实例化呢？

--  作者：有点蓝
--  发布时间：2020/9/10 22:26:00
--
没有判断Current是否空值

--  作者：裴保民
--  发布时间：2020/9/11 7:37:00
--

If Tables("充值凭证表").current("充值凭证") Is Nothing Then
Dim wjjmc As String
Dim t As Table = Tables("充值凭证表")
wjjmc =Format(T.Current("充值日期"),"yyy年MM月dd日") & "【" & T.Current("起始号") & "至" & T.Current("终止号") & "】"
Dim dlg As New FolderBrowserDialog
Dim czkh As DataRow
Dim shID As String = e.Form.Controls("czpzIDTextBox").value
Dim dr1 As DataRow = DataTables("充值凭证表").Find("充值凭证ID= \'" & shID & "\'" )
Dim str As String = dr1("充值凭证原始名称")
Dim lst As List(of String)
If dr1.isnull("充值凭证") Then
lst = new List(of String)
Else
lst =dr1.Lines("充值凭证")
End If
If FileSys.DirectoryExists(ProjectPath & "照片\\充值凭证截图\\" & wjjmc & "\\" ) Then \'如果目录C:\\MyFolder存在
For Each file As String In FileSys.GetFiles(ProjectPath & "照片\\充值凭证截图\\" & wjjmc & "\\" )
Dim name As String = FileSys.GetName(file)
If name.Contains(str) AndAlso lst.contains(name) = False Then
lst.add(name)
End If
Next
dr1.lines("充值凭证") = lst
DataTables("充值凭证表").Save
DataTables("充值凭证表").DataCols("充值凭证").DefaultFolder =ProjectPath & "照片\\充值凭证截图\\" & wjjmc & "\\"
End If
End If

启动后只能加载一条图片，其他有图片也不显示

--  作者：有点蓝
--  发布时间：2020/9/11 9:06:00
--
http://www.foxtable.com/webhelp/topics/0445.htm

自己核对单元格的文件名称是否正确和文件是否存在