Question

我有这个代码，它的结果是false而不是字符串。它所做的就是构建一个字符串。有什么想法吗？

 Dim statement As String = "Insert into table dbo.IV00101 values(" +
        "ITEMNMBR=" + "@ITEMNMBR" + "," +
        "ITEMDESC=" + "@ITEMDESC" + " , " +
        "NOTEINDX=" + "@NOTEINDX" + "," +
        "ITMSHNAM=" + DBNull.Value + "," +
        "ITEMTYPE=" + "1" + "," +
        "STNDCOST=" + "@STNDCOST" + "," +
        "CURRCOST=" + "@CURRCOST" + "," +
        "ITEMSHWT=" + "0" + "," +
        "DECPLQTY=" + "3" + "," +
        "DECPLCUR=" + "3" + "," +
        "ITMTSHID=" + DBNull.Value + "," +
        "TAXOPTNS=" + "1" + "," +
        "IVIVINDX=" + "0" + "," +
        "IVIVOFIX=" + "0" + "," +
        "IVCOGSIX=" + "0" + "," +
        "IVSLSIDX=" + "0" + "," +
        "IVSLDSIX=" + "0" + "," +
        "IVSLRNIX=" + "0" + "," +
        "IVINUSIX=" + "0" + "," +
        "IVINSVIX=" + "0" + "," +
        "IVDMGIDX=" + "0" + "," +
        "IVVARIDX=" + "0" + "," +
        "DPSHPIDX=" + "0" + "," +
        "PURPVIDX=" + "0" + "," +
        "UPPVIDX=" + "0" + "," +
        "IVRETIDX" + "0" + "," +
        "ASMVRIDX=" + "0" + "," +
        "ITMCLSCD=" + DBNull.Value + "," +
        "ITMTRKOP=" + "1" + "," +
        "LOTTYPEAC=" + DBNull.Value + "," +
        "KPERHIST=" + "0" + "," +
        "KPTRXHST=" + "0" + "," +
        "KPCALHST=" + "0" + "," +
        "KPDSTHST=" + "0" + "," +
        "ALWBKORD=" + "0" + "," +
        "VCTNMTHD=" + "1" + "," +
        "UOMSCHDL=" + "@UOMSCHDL" + "," +
        "ALTITEM1=" + DBNull.Value + "," +
        "ALTITEM2=" + DBNull.Value + "," +
        "USCATVLS_1=" + DBNull.Value + "," +
        "USCATVLS_2=" + DBNull.Value + "," +
        "USCATVLS_3=" + DBNull.Value + "," +
        "USCATVLS_5=" + DBNull.Value + "," +
        "USCATVLS_4=" + DBNull.Value + "," +
        "USCATVLS_6=" + DBNull.Value + "," +
        "MSTRCDTY=" + "1" + "," +
        "MODIFDT=" + Date.Today.ToString() + "," +
        "CREATDDT=" + Date.Today.ToString() + "," +
        "WRNTYDYS=" + "0" + "," +
        "PRCLEVEL=" + DBNull.Value + "," +
        "LOCNCODE=" + DBNull.Value + "," +
        "PINFLIDX=" + "0" + "," +
        "PURMCIDX=" + "0" + "," +
        "IVINFIDX=" + "0" + "," +
        "INVMCIDX=" + "0" + "," +
        "CGSINFLX=" + "0" + "," +
        "CGSMCIDX=" + "0" + "," +
        "ITEMCODE=" + DBNull.Value + "," +
        "TCC=" + DBNull.Value + "," +
        "PriceGroup=" + DBNull.Value + "," +
        "PRICMTHD=" + "1" + "," +
        "PRCHSUOM=" + DBNull.Value + "," +
        "SELNGUOM=" + DBNull.Value + "," +
        "KTACCTSR=" + "0" + "," +
        "LASTGENSN=" = DBNull.Value + "," +
        "ABCCODE=" + "1" + "," +
        "Revalue_Inventory=" + "1" + "," +
        "Tolerance_Percentage=" + "0" + "," +
        "Purchase_Item_Tax_Schedu=" + DBNull.Value + "," +
        "Purchase_Tax_Options=" + "1" + "," +
        "ITMPLNNNGTYP=" + "1" + "," +
        "STTSTCLVLPRCNTG=" + "0" + "," +
        "CNTRYORGN=" + DBNull.Value + "," +
        "INACTIVE=" + "0" + "," +
        "MINSHELF1=" + "0" + "," +
        "MINSHELF2=" + "0" + "," +
        "INCLUDEINDP=" + "0" + "," +
        "LOTEXPWARN=" + "0" + "," +
        "LOTEXPWARNDAYS=" + "0" + "," +
        "LASTGENLOT=" + DBNull.Value + "," +
        "Lot_Split_Quantity=" + "0.00000" + "," +
        "DEX_ROW_TS=" + Date.Today.ToString() + "," +
        "DEX_RoW_ID=" + "@DEX_RoW_ID" +
        ")"

Answer 1

正如我在评论中提到的，你的字符串连接中有一个拼写错误：

"KTACCTSR=" + "0" + "," +
"LASTGENSN=" ***=*** DBNull.Value + "," +
"ABCCODE=" + "1" + "," +

将其更改为+会让您重新开始。

在=到位的情况下，只是比较两个字符串的相等性（当然是false），然后将那个结果转换为字符串{{ 1}}。

将来有几种方法可以避免这种混乱。一种是将"False"放在文件的顶部，这将警告你这种事情。另一种方法是使用更小，更易于管理的字符串块，这样每个字符串的概率都会降低。

在调试这样的事情方面，我编译了代码，然后使用ILSpy打开它。它显示了生成的代码（即字符串比较）以及实际被比较的字符串。看到这样可以很容易地找到有问题的Option Strict On（因为它出现在字符串比较的第一个参数结束之后。）

为什么在VB.Net中评估为false？

1 个答案: