Object reference not set to an instance of an object.
 

Ah man , ive been adjusting the code so much ...

I am trying to make a treeview that display's all the directories and files on theserver (SO FAR SO GOOD) ...

Here's my code to retrieve Directories and files

public string[] GetFileList()

        {

            string[] downloadFiles;

            StringBuilder result = new StringBuilder();

            FtpWebRequest reqFTP;

            try

            {

                reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + txtftpServerName.Text + "/"));

                reqFTP.UseBinary = true;

                reqFTP.Credentials = new NetworkCredential(txtftpUserName.Text, txtftpPassword.Text);

                reqFTP.Method = WebRequestMethods.Ftp.ListDirectory;

                WebResponse response = reqFTP.GetResponse();

                StreamReader reader = new StreamReader(response.GetResponseStream());

                

                string line = reader.ReadLine();

                while (line != null)

                {

                    result.Append(line);

                    result.Append("\n");

                    line = reader.ReadLine();

                }

                result.Remove(result.ToString().LastIndexOf('\n'), 1);

                reader.Close();

                response.Close();

                

                return result.ToString().Split('\n');

            }

            catch (Exception ex)

            {

                System.Windows.Forms.MessageBox.Show(ex.Message);

                downloadFiles = null;

                return downloadFiles;

            }

        }



public string[] GetChildFileList()

        {

            string[] downloadFiles;

            StringBuilder result = new StringBuilder();

            FtpWebRequest reqFTP;

            try

            {

                reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + txtftpServerName.Text + "/" + treeView1.SelectedNode.Text + "/"));

                reqFTP.UseBinary = true;

                reqFTP.Credentials = new NetworkCredential(txtftpUserName.Text, txtftpPassword.Text);

                reqFTP.Method = WebRequestMethods.Ftp.ListDirectory;

                WebResponse response = reqFTP.GetResponse();

                StreamReader reader = new StreamReader(response.GetResponseStream());



                string line = reader.ReadLine();

                while (line != null)

                {

                    result.Append(line);

                    result.Append("\n");

                    line = reader.ReadLine();

                }

                result.Remove(result.ToString().LastIndexOf('\n'), 1);

                reader.Close();

                response.Close();



                return result.ToString().Split('\n');

            }

            catch (Exception ex)

            {

                System.Windows.Forms.MessageBox.Show(ex.Message);

                downloadFiles = null;

                return downloadFiles;

            }

        }

This works fine indevidually , but when i try to combine the two:

private void btnDoIt_Click(object sender, EventArgs e)

        {

            string[] Parent_Name = GetFileList();

            string[] Child_Name = GetChildFileList();



            treeView1.Nodes.Clear();

            if (Parent_Name != null)

            {

                /*          Parent Node             */

                foreach (string filename in Parent_Name)

                {

                    TreeNode ParentNode = new TreeNode(filename);

                    treeView1.Nodes.Add(ParentNode);



                    if (Parent_Name != null)

                    {

                        foreach (string filename2 in Child_Name)

                        {

                            TreeNode ChildNode = new TreeNode(filename2);

                            ParentNode.Nodes.Add(ChildNode);

                        }

                    }

                }

            }

        }

i get an error stating that "Object reference not set to an instance of an object." (LENS ON [foreach (string filename2 in Child_Name)] )

Can anyone maybe give me a clue ?? i dont even know why its complaining because it aught to work...

Happy coding

Re: Object reference not set to an instance of an object.
 

It works with me! but try to debug, that's the one who you can fully trust in.

Re: Object reference not set to an instance of an object.
 

Its almost certainly correct:

as you go to use Child_name, but you checked parent wasnt null, so child could be

Re: Object reference not set to an instance of an object.
 

It also works proper with me, but have some thing, that you should look at:
1. You check Parent_Name 2 times. And second one is inside the first one. It looks like question: "Are you really sure that (Parent_Name != null)" ;P

treeView1.Nodes.Clear();

            if (Parent_Name != null)

            {

and

if (Parent_Name != null)

                    {

                        foreach (string filename2 in Child_Name)

2. I suppose you should do that:

treeView1.Nodes.Add(ParentNode);

after you fill with data the ChildNode of this ParentNode.


Good luck :)

Re: Object reference not set to an instance of an object.
 

Which is what I said in a lot less of a post.

Re: Object reference not set to an instance of an object.
 

Oh yeah :( sorry. First part is your's. Wasn't about to do things like that O.O ... it seems that I need rest a bit ;P

Re: Object reference not set to an instance of an object.
 

Welll well well, i feel like a retard now hahahahahahahaha!!!

Although , thats not the problem...

The problem lies here

for some reason (i think) the Uri does not change because you have to SELECT a node first...

So i did this

private void btnDoIt_Click(object sender, EventArgs e)

        {

            string[] Parent_Name = GetFileList();

            



            treeView1.Nodes.Clear();

            if (Parent_Name != null)

            {



                /*          Parent Node             */

                foreach (string filename in Parent_Name)

                {

                    TreeNode ParentNode = new TreeNode(filename);

                    

                    // changed the GetChildFileList uri to 'reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + txtftpServerName.Text + "/" + txtShowDirectory.Text + "/"));'



                    txtShowDirectory.Text = filename;



                    string[] Child_Name = GetChildFileList();



                    if (Child_Name != null)

                    {

                        foreach (string filename2 in Child_Name)

                        {

                            TreeNode ChildNode = new TreeNode(filename2);

                            ParentNode.Nodes.Add(ChildNode);

                        }

                    }

                    treeView1.Nodes.Add(ParentNode);

                }

            }

        }

WORKS LIKE A BOMB!!!!!!!!

cept i still get an error on my try -> catch saying

Obviously there is still some kind of error

Re: Object reference not set to an instance of an object.
 

Look i know the problemo is this

but i cant really bypass that one or can I ???

Re: Object reference not set to an instance of an object.
 

Well if Child_name is null, then look at your function