从字符串转换为整数是无效的linq

Question

我是Linq的新人。错误（从字符串＆＃34转换; SYMBOL＆＃34;到整数类型无效）出现在以下行中：＆＃39; r（＆＃34; SYMBOL＆＃34;）= q！SYMBOL.ToString＆＃39;。请帮忙

Dim tblBhavNSEFO As DataTable = gbl_dsBhavNSEFO.Tables(0)
Dim tblSource As New DataTable
tblSource.Columns.Add("SYMBOL", GetType(String))

Dim tblsymbols As DataTable = (From s In tblBhavNSEFO _
                       Where s!INSTRUMENT = strCondition _
                       Order By s!SYMBOL Ascending _
                       Select s).CopyToDataTable
Dim filter = From f In tblsymbols _
           Select f!SYMBOL Distinct

If filter.Count > 0 Then
    For Each q In filter
        Dim r = tblSource.NewRow()
        r("SYMBOL") = q!SYMBOL.ToString
        tblSource.Rows.Add(r)
    Next

Answer 1

循环变量q已经包含符号（您在f!SYMBOL的定义中投射到filter上）。因此，不必将!SYMBOL添加到q。