主题：[求助]设计导入器的时候 怎么定义导入空表时不报错

空表？指excel文件没有sheet？

stname.SelectedIndex = 0

改成

If stname.combolist = Nothing Then Return

stname.SelectedIndex = 0

贴出按钮的代码，贴出报的错误。

按钮代码

Dim bookname As WinForm.TextBox = e.Form.Controls("bookName")
If bookname.Value = "" Then
   
    MessageBox.show("请点击 [Excel文件] 按钮,选取Excel文件! ","错误提示",MessageBoxButtons.OK,MessageBoxIcon.Error)
    Return
End If

Dim sheetname As WinForm.ComboBox = e.Form.Controls("sheetname")
If sheetname.SelectedValue = "" Then
    MessageBox.show("导入工作表不能为空 ! ","错误提示",MessageBoxButtons.OK,MessageBoxIcon.Error)
    Return
End If

Dim Book As New XLS.Book(bookname.text)
Dim sheet As XLS.Sheet = book.sheets(sheetname.SelectedValue)
Dim bt As WinForm.CheckBox = e.Form.Controls("标题")
'设定最大取值列
Dim maxc As WinForm.NumericComboBox = e.Form.Controls("最大列")
If maxc.value > sheet.Cols.Count Or maxc.value = 0 Then
    maxc.Value = sheet.Cols.Count
End If
Dim qsh As WinForm.NumericComboBox = e.Form.Controls("有效起始行")
Dim cblst As String
'------遍历数据-----
Dim qs As Integer = cint(qsh.Text)
For r As Integer = qs-1 To qs+6
    Dim lst As String = ""
    For c As Integer = 0 To maxc.value - 1
        Dim data As String = sheet(r,c).value
        lst = lst & data.PadLeft(8," ") & ","
    Next
    cblst = cblst & lst & "|"
Next
'-----标题-----'
Dim h As String

Dim cbl As String = ""

'dcl.ComboList = cbl.TrimEnd("|")