Initialize Correct Value to Avoid Object variable or With block variable not set - vba

Question

I have block of code where I'm using a For... Next loop to go through an Excel sheet, and tell me if values entered in the text boxes were found or not. I've modified it to work if the values match. Yet, I'm receiving the Object/With Block variable not set error, and it confusing me. I've created the following:
Dim Value2Find_1 As String = txtMachNumber.Text 'Serial number value.
Dim Value2Find_2 As String = txtMachName.Text 'Machine name value.
Dim ReplaceWithValue1 As String = "" 'Replaces the serial number value if found in the sheet.
Dim ReplaceWithValue2 As String = "" 'Replaces the machine name value if found in the sheet.
Dim ReplaceWithValue3 As String = "" 'Replacement for the date-time in the Date Column.
Dim Range2Use_1 = xlWS.Range("A1:A4000") 'Range to span the A Column.
Dim Range2Use_2 = xlWS.Range("B1:B4000") 'Range to span the B Column.
Dim Range2Use_3 = xlWS.Range("F1:F4000") 'Range to span the F Column.
Dim xlCell_A = Range2Use_1.Find(txtMachNumber.Text) 'Looks up the searched serial value in A Column.
Dim xlCell_B = Range2Use_2.Find(txtMachName.Text) 'Looks up the searched machine value in B Column.
Dim LastRow = xlWS.Range("A4000").End(Excel.XlDirection.xlUp).Row + 1
Dim i As Integer
With xlWS
For i = 1 To LastRow
If Not (Value2Find_1 = txtMachNumber.Text And Value2Find_2 = txtMachName.Text) Then
MessageBox.Show("No value exists here...")
Else
Range2Use_1.Find(What:=Value2Find_1, MatchCase:=True)
Range2Use_2.Find(What:=Value2Find_2, MatchCase:=True)
MsgBox("Found both values: " & Value2Find_1 & " and " & Value2Find_2 & " on row " & xlCell_A.Row)
End If
Exit Sub
Next
End With
If my textbox entries are not in the sheet, the errors returns on the following line of code:
MsgBox("Found both values: " & Value2Find_1 & " and " & Value2Find_2 & " on row " & xlCell_A.Row)
I've narrowed it down to have something to do with the variable that returns the row number of the located textbox entries - xlCell_A. This is where I'm stuck, however. What do I need to set this as in order to avoid the Object/With Block variable not set error? I am afraid I don't know what this is asking for.

Answer 1

I think the problem with your code is that the Find method returns Nothing whenever no match is found, as stated in its documentation. Thus, xlCell_A.Row returns the error because the Row method cannot be called on Nothing.
Actually, I see a number of further issues with your code:
The interior of the for loop does not depend on the loop variable i. Hence, it does exactly the same thing in each interation.
The variable xlWS of the With block is never used, which makes the With block unnessesary.
The return values of the Find methods in the loop never gets assigned to anything. Because of this, they have no effect.
The condition in the if statement always returns False since you never change the values of Value2Find_1 and Value2Find_2 and you initialized them to txtMachNumber.Text and txtMachName.Text, respectively.
If you intend to evaluate whether the values txtMachNumber.Text and txtMachName.Text are present in the column A and B, respectively, you can just test whether xlCell_A and xlCell_B are Nothing.
Since you want to find both on the same row, which using Find does not guarantee, it might be easier to use a loop as in your code but replace
txtMachNumber.Text and txtMachName.Text with Range2Use_1.Cells(i,1) and Range2Use_2.Cells(i,1) in the if statement. (This compares the value in the ith row with the values to search for.) Obviously, you would have to exit the loop after finding a match, e.g. using the break statement.