[RESOLVED] on error goto doesn't work twice

hi,

I need something done for multiple textboxes. It works for the first one, but it reaches the second one, the debugging stops because of an error :( Normally it should go on to the next step when this error appears, but this only works for textbox1 :(

here's the code:

Code:

---

        If CheckBox1.Checked = True Then
            Dim ary() As String
            ary = TextBox1.Text.Split(vbCrLf)
            Dim i As Integer
            i = 0
            If TextBox1.Text <> "" Then
                i = 0
                TextBox1.Text = TextBox1.Text.Replace("megaupload", "megavideo")
                Do
                    On Error GoTo nextstep2
                    ary = TextBox1.Text.Split(vbCrLf)
                    If ary(i).Contains("megavideo.com/?d=") Then
                        Dim webResponse3 As System.Net.HttpWebResponse = Nothing
                        Dim webRequest3 As System.Net.HttpWebRequest = System.Net.HttpWebRequest.Create(ary(i))
                        webResponse3 = DirectCast(webRequest3.GetResponse(), System.Net.HttpWebResponse)
                        Dim srResp As System.IO.StreamReader
                        srResp = New System.IO.StreamReader(webResponse3.GetResponseStream())
                        Dim SOMESTRING As String
                        SOMESTRING = srResp.ReadToEnd
                        If SOMESTRING.Contains("video is unavailable") Then
                            If vlinks = "" Then
                                vlinks = "Video is not available"
                            Else
                                vlinks = vlinks & vbCrLf & "Video is not available"
                                TextBox28.Text = vlinks
                            End If
                        ElseIf SOMESTRING.Contains("This video has been removed due to infringement") Then
                            If vlinks = "" Then
                                vlinks = "Video is not available"
                            Else
                                vlinks = vlinks & vbCrLf & "Video is not available"
                                TextBox28.Text = vlinks
                            End If
                        Else
                            For h As Integer = 0 To SOMESTRING.Split("'").Length - 1 Step 1
                                If (SOMESTRING.Split("'")(h).ToLower().Contains("previewplayer/?v=")) Then
                                    If vlinks = "" Then
                                        vlinks = SOMESTRING.Split("'")(h).Replace("previewplayer", "http://megavideo.com")
                                    Else
                                        vlinks = vlinks & vbCrLf & SOMESTRING.Split("'")(h).Replace("previewplayer", "http://megavideo.com")
                                    End If
                                    TextBox28.Text = vlinks
                                End If
                            Next
                        End If
                    Else
                        If vlinks = "" Then
                            vlinks = "This line wasn't a MU/MV d-link"
                        Else
                            vlinks = vlinks & vbCrLf & "This line wasn't a MU/MV d-link"
                            TextBox28.Text = vlinks
                        End If
                    End If
                    i = i + 1
                Loop
            End If
nextstep2:
            If TextBox2.Text <> "" Then
                i = 0
                TextBox2.Text = TextBox2.Text.Replace("megaupload", "megavideo")
                Do
                    On Error GoTo nextstep3
                    ary = TextBox2.Text.Split(vbCrLf)
                    If ary(i).Contains("megavideo.com/?d=") Then
                        Dim webResponse3 As System.Net.HttpWebResponse = Nothing
                        Dim webRequest3 As System.Net.HttpWebRequest = System.Net.HttpWebRequest.Create(ary(i))
                        webResponse3 = DirectCast(webRequest3.GetResponse(), System.Net.HttpWebResponse)
                        Dim srResp As System.IO.StreamReader
                        srResp = New System.IO.StreamReader(webResponse3.GetResponseStream())
                        Dim SOMESTRING As String
                        SOMESTRING = srResp.ReadToEnd
                        If SOMESTRING.Contains("video is unavailable") Then
                            If vlinks = "" Then
                                vlinks = "Video is not available"
                            Else
                                vlinks = vlinks & vbCrLf & "Video is not available"
                                TextBox28.Text = vlinks
                            End If
                        ElseIf SOMESTRING.Contains("This video has been removed due to infringement") Then
                            If vlinks = "" Then
                                vlinks = "Video is not available"
                            Else
                                vlinks = vlinks & vbCrLf & "Video is not available"
                                TextBox28.Text = vlinks
                            End If
                        Else
                            For h As Integer = 0 To SOMESTRING.Split("'").Length - 1 Step 1
                                If (SOMESTRING.Split("'")(h).ToLower().Contains("previewplayer/?v=")) Then
                                    If vlinks = "" Then
                                        vlinks = SOMESTRING.Split("'")(h).Replace("previewplayer", "http://megavideo.com")
                                    Else
                                        vlinks = vlinks & vbCrLf & SOMESTRING.Split("'")(h).Replace("previewplayer", "http://megavideo.com")
                                    End If
                                    TextBox28.Text = vlinks
                                End If
                            Next
                        End If
                    Else
                        If vlinks = "" Then
                            vlinks = "This line wasn't a MU/MV d-link"
                        Else
                            vlinks = vlinks & vbCrLf & "This line wasn't a MU/MV d-link"
                            TextBox28.Text = vlinks
                        End If
                    End If
                    i = i + 1
                Loop
            End If
        End If
nextstep3:

---

all help is greatly appreciated!

if you know another method to go to the next step when an error occurs (the error is that arr(i) doesn't exists anymore) it's good as well

thanks in advance

LW

Don't use On Error Goto with VB.NET. Ever.

Use Try...Catch...Finally...End Try

Catch and Finally are both optional, but at least one if them has to be present.

Example:

Code:

---

        Dim i As Integer
        Try
            i = 300 / 0
        Catch ex As Exception
            'Oh no!  Something happened between "Try and Catch"... do this instead:
            i = 0

        Finally
            'Do this after you do everything else.
        End Try

---

I didn't even know On Error GoTo was still supported in .NET (probably shouldn't be)

You can use Try/Catch for each of your textboxes

I agree with Jenner.

Where is the error exactly, and what is the error exactly?

Yes, what is the error? Since you are using IO, error handling is important, but if you can test for the error condition before it happens, the code will run faster, as raising an exception is rather slow.

In general, you could replace your On Error statement with Try, then the NextStep2 would probably be best in the Finally block (add the catch block, but you can leave it empty if you want). You would wrap that NextStep2 in a second Try...Catch block to catch any exceptions in that block.

However, once again, wherever possible, test for the exceptional condition rather than just counting on the error handling.

thanks for the replies. The error is that when arr()=textbox1.text.split(vbcrlf) reaches the last possible line while looping (changes everytime). After this arr(i) doesn't exists so it gives an error. From then it should go to nextstep. So this is not a real error, just an indication that I have looped all the lines of textbox1, and so it should begin again with textbox2.

I already tried the try catch method, but this also didn't work properly, so I found this method, but I'l try again and cross my fingers...

example of error:

textbox1.text =

Code:

---

megavideo.com/?v=AAAAAAAA
megavideo.com/?v=AAAAAAA6
megavideo.com/?v=AAAAAAA5
megavideo.com/?v=AAAAAAA1
megavideo.com/?v=AAAAAAA2

---

So the program loops through all the lines using

Code:

---

arr = TextBox1.text.split(vbcrlf)

---

and arr(i) where i always changes. But when i reaches 5 in this example (line1 = arr(0)) it gives an error here:

Code:

---

                        Dim webRequest3 As System.Net.HttpWebRequest = System.Net.HttpWebRequest.Create(ary(i))

---

as it cannot create the web page ary(5) as ary(5) doesn't exists...
so then it should stop with textbox1 and go on with textbox2

This all works fine, but when he starts with textbox2 the "on error goto" just doesn't work and it the program crashes...

EDIT: I tried with try again, and this time it worked fine! I was probably doing something wrong last time... for the interested people:

Code:

---

        If TextBox1.Text.EndsWith(vbCrLf) Then
            TextBox1.Text.Remove(TextBox1.Text.Length - 1, TextBox1.Text.Length)
        End If
        Dim vlinks As String
        If CheckBox1.Checked = True Then
            Dim ary() As String
            ary = TextBox1.Text.Split(vbCrLf)
            Dim i As Integer
            i = 0
            If TextBox1.Text <> "" Then
                i = 0
                TextBox1.Text = TextBox1.Text.Replace("megaupload", "megavideo")
                Do
                    Try
                        ary = TextBox1.Text.Split(vbCrLf)
                        If ary(i).Contains("megavideo.com/?d=") Then
                            Dim webResponse3 As System.Net.HttpWebResponse = Nothing
                            Dim webRequest3 As System.Net.HttpWebRequest = System.Net.HttpWebRequest.Create(ary(i))
                            webResponse3 = DirectCast(webRequest3.GetResponse(), System.Net.HttpWebResponse)
                            Dim srResp As System.IO.StreamReader
                            srResp = New System.IO.StreamReader(webResponse3.GetResponseStream())
                            Dim SOMESTRING As String
                            SOMESTRING = srResp.ReadToEnd
                            If SOMESTRING.Contains("video is unavailable") Then
                                If vlinks = "" Then
                                    vlinks = "Video is not available"
                                    TextBox28.Text = vlinks
                                Else
                                    vlinks = vlinks & vbCrLf & "Video is not available"
                                    TextBox28.Text = vlinks
                                End If
                            ElseIf SOMESTRING.Contains("This video has been removed due to infringement") Then
                                If vlinks = "" Then
                                    vlinks = "Video is not available"
                                    TextBox28.Text = vlinks
                                Else
                                    vlinks = vlinks & vbCrLf & "Video is not available"
                                    TextBox28.Text = vlinks
                                End If
                            Else
                                For h As Integer = 0 To SOMESTRING.Split("'").Length - 1 Step 1
                                    If (SOMESTRING.Split("'")(h).ToLower().Contains("previewplayer/?v=")) Then
                                        If vlinks = "" Then
                                            vlinks = SOMESTRING.Split("'")(h).Replace("previewplayer", "http://megavideo.com")
                                        Else
                                            vlinks = vlinks & vbCrLf & SOMESTRING.Split("'")(h).Replace("previewplayer", "http://megavideo.com")
                                        End If
                                        TextBox28.Text = vlinks
                                    End If
                                Next
                            End If
                        Else
                            If vlinks = "" Then
                                vlinks = "This line wasn't a MU/MV d-link"
                                TextBox28.Text = vlinks
                            Else
                                vlinks = vlinks & vbCrLf & "This line wasn't a MU/MV d-link"
                                TextBox28.Text = vlinks
                            End If
                        End If
                    Catch ex As Exception
                        GoTo nextstep2
                    End Try
                    i = i + 1
                Loop
            End If
        End If
nextstep2:
        vlinks = ""
        TextBox1.Text = TextBox28.Text.Replace("&width=", "")
        If TextBox2.Text <> "" Then
            Dim i As Integer
            Dim ary() As String
            i = 0
            TextBox2.Text = TextBox2.Text.Replace("megaupload", "megavideo")
            Do
                Try
                    ary = TextBox2.Text.Split(vbCrLf)
                    If ary(i).Contains("megavideo.com/?d=") Then
                        Dim webResponse3 As System.Net.HttpWebResponse = Nothing
                        Dim webRequest3 As System.Net.HttpWebRequest = System.Net.HttpWebRequest.Create(ary(i))
                        webResponse3 = DirectCast(webRequest3.GetResponse(), System.Net.HttpWebResponse)
                        Dim srResp As System.IO.StreamReader
                        srResp = New System.IO.StreamReader(webResponse3.GetResponseStream())
                        Dim SOMESTRING As String
                        SOMESTRING = srResp.ReadToEnd
                        If SOMESTRING.Contains("video is unavailable") Then
                            If vlinks = "" Then
                                vlinks = "Video is not available"
                            Else
                                vlinks = vlinks & vbCrLf & "Video is not available"
                                TextBox28.Text = vlinks
                            End If
                        ElseIf SOMESTRING.Contains("This video has been removed due to infringement") Then
                            If vlinks = "" Then
                                vlinks = "Video is not available"
                            Else
                                vlinks = vlinks & vbCrLf & "Video is not available"
                                TextBox28.Text = vlinks
                            End If
                        Else
                            For h As Integer = 0 To SOMESTRING.Split("'").Length - 1 Step 1
                                If (SOMESTRING.Split("'")(h).ToLower().Contains("previewplayer/?v=")) Then
                                    If vlinks = "" Then
                                        vlinks = SOMESTRING.Split("'")(h).Replace("previewplayer", "http://megavideo.com")
                                    Else
                                        vlinks = vlinks & vbCrLf & SOMESTRING.Split("'")(h).Replace("previewplayer", "http://megavideo.com")
                                    End If
                                    TextBox28.Text = vlinks
                                End If
                            Next
                        End If
                    Else
                        If vlinks = "" Then
                            vlinks = "This line wasn't a MU/MV d-link"
                        Else
                            vlinks = vlinks & vbCrLf & "This line wasn't a MU/MV d-link"
                            TextBox28.Text = vlinks
                        End If
                    End If
                Catch ex As Exception
                    GoTo nextstep3
                End Try
                i = i + 1
            Loop
        End If
nextstep3:
        vlinks = ""
        TextBox2.Text = TextBox28.Text.Replace("&width=", "")

---

was the solution...

Thanks for all your help! You really helped me and much other people that will use the program :D

Code:

---

        'arr(0) megavideo.com/?v=AAAAAAAA
        'arr(1)megavideo.com/?v=AAAAAAA6
        'arr(2)megavideo.com/?v=AAAAAAA5
        'arr(3)megavideo.com/?v=AAAAAAA1
        'arr(4)megavideo.com/?v=AAAAAAA2

        'loop through array without error
        For i = 0 To arr.Length - 1

        Next

---

Code:

---

For Each s As String In arr
  'Each element of arr becomes "s" in this loop.
Next

---

thanks, that was what I was searching for, but I trying with the .exist and that didn't work...
Thanks again!