How to: populate TreeView control from a database in VB.NET

[@mkaatr]

Hi there... Assuming the selected node stores the primary key of the value in its tag property, you could use that to update the db: Dim Key=TreeView1.SelectedNode.Tag Dim Val=TextBox1.Text Dim TA as new MyTableAdapter TA.Update(Key,Val) this code is just for illustration so that you could get the idea. It need modification based on your work/problem.

[@gstringavenger]

Very good. I was searching all over for a tutorial like this. thanks.

[@bsworldsolution6626]

well detail tutorial, please how can i populate the treeview to textbox from a different table

[@mkaatr]

Hi there... I made many tutorials previously regarding this. What you are asking is simply combining multiple ideas which is not too hard. Try to check the database tutorials in the website, also check out the question & answer, and the how to sections there.

[@mkaatr]

Hi... Not sure if I got your question right, do you mean that you want to update the db and then the tree should be updated? If so you could simply reload the tree from db. Does that answer your question or did I misunderstood you?

[@bigbirdpukindog]

How would you handle "open DataReader associated with this Connection which must be closed first" error with mysql? Mysql doesn't support MultipleActiveResultSets=True

[@i7arithran]

Yes mate that's exactly what i want. But how can you update the database from a string variable ?

[@sumair4u]

Dear Mkaatr,, i tried it with my SQLSERVER Database, but it gave me the following error: "There is already an open DataReader associated with this Command which must be closed first." After that I Surrounded the Filltree by Catch Try, it didnot gave the error mention above, but not working propely, i mean it showing only Parent items, not child,, plz tell me whats the problem Thank you

[@liakutalikhan6190]

Showing An unhandled exception of type 'System.Data.OleDb.OleDbException' occurred in System.Data.dll what to do

[@DupczacyBawol]

Works a lillte slow when you got 200 nodes with 4-5 subnodes inside... about 1000 queries to DB? But very useful tutorial. Thank you :)

[@mkaatr]

Readme .txt Just try SuspendLayout before filling the treeview, then ResumeLayout after that. This should make things a little bit faster. Also you could create an index on the node_parent column. This should speed things up.

[@mkaatr]

@sumair4u Hi there... Sorry for the late response. In SQL Server, each time you open a DataReader, you can't open another one unless you close the previous first. To solve this, add the following to the end of the connection string: MultipleActiveResultSets=True yours sincerely.

[@i7arithran]

Hey man, Great Tutorial Can you post a method for updating the database ; The value from a textbox to a selected node as a child.or something similar. Cheers mate!

[@adiyehan]

i got an error in the line "Dim dr = cmd.ExecuteReader" Data type mismatch in criteria expression. please help

[@teyenk13]

oooh i use mysql, i use MySql.Data.MySqlClient.MySqlDataReader to dr... but i got error in the recursive function.. can you help me?

[@dealerlinksystems]

It's a GREAT way to do it, just what I was looking for... Can you please assist with one more thing thou. Im setting up a treeview to select, then open each PDF (I use process.start to open the PDF which works fine) but how can I setup the link from the "selected treeview node, to open the selected pdf" (the pdf list is hard coded, so no DB is used) I'm just outside Toronto, Canada... Your kind assistance would be key to my project, Thank you in advance, Drew (SYKPE ID "drew.wells2")

[@Felixantony84]

nice tutorial. thank you verymuch sir.........

[@mkaatr]

@mellwell2005 You are welcome.

[@mkaatr]

@waroftheworldseu Sorry about that, I updated the title as suggested. yours.

[@1972pms]

very useful tutorial

[@sauryjorge]

Gracias me resuelto útil para lo que quería, gracias!

[@bopert]

thank you sir!

[@mkaatr]

@aalamnaryab Hi there... search the website for : "Re: alamnaryab - view hard disk dir in treeview" or just search the questions and answers section. I uploaded a video for that. yours

[@أكواد-غ4ص]

Thank U

[@neilmas]

gracias.

[@ЛашинДанил-р6к]

OMG 11 LET