如何修复nullreference异常错误 [英] How to fix the nullreference exception error

问题描述

Dim SearchID As String
        Dim I As Integer
        Dim J As Integer
        
        Try


            SearchID = txtArticle.Text
            J = Dst.TABLES("PRODUCTS").ROWS.COUNT - 1  ---> nullreference error

            I = 0


            While I <> J + 1
                If SearchID = Dst.TABLES("PRODUCTS").ROWS(I)("ARTICLE") Then
                    ShowData(I)
                    Exit While
                ElseIf I = J Then
                    MsgBox("RECORD NOT FOUND")
                    ShowData(CurrentRow)
                    Exit While



                End If
            End While

            I += 1
            CurrentRow = I
        Catch EX As Exception
            MsgBox(EX.Message)
        End Try

推荐答案

检查Dst.TABLES（PRODUCTS）产品是否真的存在。

越过 [ ^ ]和观看 [ ^ ]代码中的变量可以帮助你弄清楚可能是什么null因此找到了这些问题的根源。

Check if Dst.TABLES("PRODUCTS") product really exists.
Stepping through[^] and watching[^] variables in your code can help you figure out what could be null and thus get to the root of such issues.

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