Streamreader read next line if empty row - vb.net

Question

I have a problem when i want to use streamreader readline by line my text file. The streamreader i using is by taking the substring, but when it comes to empty rows it pop up this error message "Index and length must refer to a location within the string". It is not exactly empty row or line, but it contains this thing "ÐôÐ#(ôd". How to skip or ignore or delete the row that not have appropriate line in text file?This is my code
For Each finalname In filenames
row2 = 1
Using reader As New StreamReader(finalname)
Do Until reader.EndOfStream
Dim line As String = reader.ReadLine
Dim datetimestring As String = line.Substring(0, 22)
datetimestring = datetimestring.Replace("""", "").Trim()
datetimestring = datetimestring.Replace("-", "").Trim()
Dim format As String = "dd/MM/yyyy hh:mm:ss tt"
Dim time As DateTime = DateTime.Parse(datetimestring)
Dim Dt = time.ToString(format)
'Dim dtime As DateTime = DateTime.Parse(Dt)
Dim c As String = line.Substring(22)
c = c.Replace("-", "").Trim()
Dim cmd1 As New SqlCommand("insert into table5([time] , [process], [oven], [line]) values ( #line , #line1, '" & oven & "', '" & row2 & "')", con1)
cmd1.Parameters.Add("#line", SqlDbType.DateTime).Value = time
cmd1.Parameters.Add("#line1", SqlDbType.NVarChar).Value = c
con1.Open()
cmd1.ExecuteNonQuery()
con1.Close()
row2 = row2 + 1
Loop
oven = oven + 2
Dim str20 As String = "data source=10.239.213.40;uid=sa;pwd=Win32API;database=mbi"
Dim con20 As New SqlConnection(str20)
Dim com20 As String = "select top 9 * from table5 where process like '%Load lot clicked%' or process like '%''QCheck'' Button%' or process like '%''Start'' Button%' or process like '%Run Proc%' or process like '%Run Bin2 clicked%' or process like '%Started with Double click%' and oven ='2' order by oven, line desc"
Dim Adpt20 As New SqlDataAdapter(com20, con1)
Dim ds2 As New DataSet()
Adpt20.Fill(ds2, "table5")
DataGridView1.DataSource = ds2.Tables(0)
End Using
Next

Answer 1

Try this
Dim line As String = reader.ReadLine
If(String.ISNullorWhiteSpace(line) = false Then
Dim datetimestring As String = line.Substring(0, 22)
datetimestring = datetimestring.Replace("""", "").Trim()
datetimestring = datetimestring.Replace("-", "").Trim()
Dim format As String = "dd/MM/yyyy hh:mm:ss tt"
Dim time As DateTime = DateTime.Parse(datetimestring)
Dim Dt = time.ToString(format)
'Dim dtime As DateTime = DateTime.Parse(Dt)
Dim c As String = line.Substring(22)
c = c.Replace("-", "").Trim()
Dim cmd1 As New SqlCommand("insert into table5([time] , [process], [oven], [line]) values ( #line , #line1, '" & oven & "', '" & row2 & "')", con1)
cmd1.Parameters.Add("#line", SqlDbType.DateTime).Value = time
cmd1.Parameters.Add("#line1", SqlDbType.NVarChar).Value = c
con1.Open()
cmd1.ExecuteNonQuery()
con1.Close()
row2 = row2 + 1
End If
If line.Substring is the issue then check with something like this
Dim lineLength As Int = line.Length()
Dim datetimestring As String =If(line.Substring(0, 22) = Null, "", ine.Substring(0, 22))
Dim datetimestring As String =If(lineLength < 22, "", line.Substring(0, 22))

Answer 2

I wouldn't use SubString function, as you noted when a line is shorter than 22 characters the program will crash.
Typically I will subdivide or split the line into different parts by using Split function, for example:
dim ast() as string = line.split("XXX")
then extract the specific string from it:
datetimestring = ast(0)
this, of course, requires the parts are seperated by common delimiters, such as ',' or empty spaces, etc.
Also, add additional condition after reading the line, for example:
Dim line As String = reader.ReadLine
If String.ISNullorWhiteSpace(line) orelse line.length < 10 Then continue do

Answer 3

Do Until reader.EndOfStream
Dim line As String = reader.ReadLine
If Not String.IsNullOrWhiteSpace(line) AndAlso Not line.Length < 22 Then
'put the rest of your do-loop code here
End If
Loop