Possible To Show Structure Of A Class In A Treeview?
May 31, 2009is it possible to show the structure of a class in a treeview? if yes how
View 3 Repliesis it possible to show the structure of a class in a treeview? if yes how
View 3 RepliesI'm new to VB 2008 after having spent a long time with VB6, so I apologize if this is a stupid question. But I'd really like to have this straightened out.
Let's say I have a pretty large structure that has lots of properties.
Code:
Now say that I want an internal database with about 10 instances of this structure total, describing, say, 10 different products that a store sells. When these values are loaded from a database, they remain totally static. (However, they can be different each time a program loads)
Now say that I have a class. Each instance of this class is a type of that BaseProduct structure. Meaning, each instance of the class pertains to one of the 10 types of products that the store sells. However, this class has additional properties that pertain specifically to each instance, which are not static.
Code:
Now, the problem here is... If I have 200 different transactions, each one contains an instance of BaseProduct. BaseProduct is HUGE, and is largely redundant (only 10 types possible), so I think it's a little silly to include a whole copy of it with EVERY transaction. However, the Transaction class really needs information regarding the base product it pertains to. Is there a way to, instead of declaring a New BaseProduct in the Transaction class, to simply make one of the properties of the Transaction class a pointer to a BaseProduct variable?
In VB6, I would accomplish this by making a BaseProduct(10) array, and then giving each Transaction an ID number referring to an entry in that array. But in VB 2008, using class structure, this is impossible. I can't define the BaseProduct(10) array outside of a class in a namespace, and if I define it in the actual application's form, then the class loses modularity since it relies on the application that's using it.
I'm having a problem that's driving me crazy; I can't understand how to convert the XML structure into a class structure (that I want to use to hydrate a XML document).
The XML document looks like this:
xml
<?xml version="1.0" encoding="utf-8"?>
<artists xmlns:opensearch="http://a9.com/-/spec/opensearch/1.1/" xmlns="http://www.spotify.com/ns/music/1">
[code]....
The General TreeView Structure, with the level indicated in the left.[code...]
Leaving the 0 and 1 levels, the other levels has to be treated as above. How to achieve this?
am trying to pupulate a treeview nodes base on directory structure like this
[Code]...
The above code works for add base/parent node say i have a urllike this [URL] in this case, it should create a child node dir2 in parent node dir1 am getting confused add child nodes to the existing nodes
I have something that is working for the most part, but I'm having some trouble with restricted-access folders.
The code I'm using is as follows:
Imports System.IO
Public Class frmMain
Private Sub frmMain_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
For Each drive In DriveInfo.GetDrives
[Code] .....
For testing purposes I replaced this section...
If drive.IsReady Then
PopulateTree(drive.ToString, TreeView1.Nodes(i))
End If
...with this...
If drive.toString = "L:"
PopulateTree(drive.ToString, TreeView1.Nodes(i))
End If
And it worked fine for that drive. The L: is a removable USB drive by the way.
However, with the original code I get debug errors on some folders because they are access-restricted. Is there any way to ignore those particular folders and show the rest?
Is it possbile to to fill a TreeView in a Windows Form with the folder structure of a SharePoint site?
View 3 RepliesI'm sure there are several ways of achieving my goal but I am after opinions on what you think is the best option. I'm writing a vb.net application which (amongst other thinks) interfaces with media players in the home. Because there are different types of media playersI'm trying to structure it so each type of media player has it's own class which interfaces to a management class which sits on top of all the different devices types.
The device classes are responsible for discovering the phsyical devices and returning that information up to the management class. A device class may be responsible for monitoring 1 or more physical devices so..
[Code]...
Currently, if I have different classes containing functions etc, I would structure them all in the 1 VB file titled whatever the main Class is. For example:
[Code]...
However, the problem with this is the file can become 1000s of lines long making hard to find portions of code. Is there a way I can store SubClass in a file such as MainClass.SubClass.vb so that its easier to locate classes? Or is there a better, more standard, way of doing this?
In a recent project I was working I created a structure in my class to solve a problem I was having, as a colleague was looking over my shoulder he looked derisively at the structure and said "move it into a class". I didn't have any argument for not moving it into a class other than I only need it in this class but this kind of falls down because couldn't I make it a nested class?
View 5 RepliesI wanna show a form when clicking on a node of treeview
for example when clicking on node 0 i wanna show a form like the treeview in ASP.NET(every node return us to a specific URL) and i have many nodes with children
I didnt find what i want when looking for that in the web.
I have the following code for a treeview, It only shows a +sign against some folders, mostly system folders but not others, a mod to this code to show all childs, irrespective of how many levels the child folders exist?
Dim basenode As System.Windows.Forms.TreeNode
If IO.Directory.Exists(path) Then
If path.Length <= 3 Then
[code]....
show the files in the particular folder using treeview but i dont have icons for all files windows select the icons for particular files can i select in the same way
View 10 RepliesThis is purely a coding practice question concerning VB.NET structures. Where do you keep one?As an example, I've created a structure for the simple purpose of keeping information organized, I'd like this structure to be stand-alone, not belonging to any class so I wouldn't have to access it through SomeClass.MyStructure but rather simply MyStructure. So, do I keep it in a separate class and import it into my namespace? Do I keep it in a module (Static class, essentially)? Do I just make a separate VB.NET code file and place is there (I would like it to live in a separate file). Just to clarify, I need this structure to be accesses by the whole application, not just a single class.
View 1 RepliesCould someone write me a Class structure for passing the data array below.
Function function1(Byval input1 as Double, Byval input2 as Double, Byval input3 as Double)
'code'
data.data1=value1
[code].....
Any code snippet they could post that will take a specified folder & show the files & subfolders hierarchy in a TreeView?
View 11 RepliesI am attempting to show a specific form using a treeview control, the nodes of which have their tag value set to an instance of the Form I need to show. The code I have in the DoubleClick event works great for the first time I show a form, but after that I get an object disposed exception. As you can see, I tried handling it by resetting the tag, but that didn't work. Is there any way I can show the form more than once without going through a switch statement anytime the exception comes up and resetting the tag to the right type of form? I'd like something nicer looking like the way I show the form.
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim fm2 As New Form2()
Dim fm3 As New Form3()
TreeView1.Nodes(0).Tag = fm2
[Code] .....
i need to show the system folders of computer in Treeview
My computer
C:
D:
like this
I do have a TreeView inside a splitterpanel-control. After executing the ExpandAll()-Method, a scrollbar appears on the panel and the first nodes are no longer visible, because the panel scrolled down to the bottom-nodes. How do scroll back to the top-nodes programmatically, because I want the user to see the first nodes on the top?
View 2 RepliesI'm working with VB2008 and I was wondering how to get the treeview to show the relative, relationship, key ect....vb6 Example
Treeview.Nodes.Add Relative, Relationship, Key, Text, Image, SelectedImage
I would like to be able to use the treeview this way but if there is another way can someone let me know, I have searched the net and have looked in a few books and cannot figure this out.
I have a serializable class and structure I created for an ArrayList to be access within a Web Application. The problem I am having is the count comes back as zero after calling New. I debugged the code and the Arrylist is being populated
View 3 RepliesI am trying to figure out a class/struture to handle the following JSON format:
{
"ReturnData": [
{
"id": "msg2DoesNotExistName",
[Code]......
I may or may not have Data for ReturnData and SetValue (one or both at a minimum). I am trying to let the serializer handle most of the formatting without having to check for empty sections and single-item arrays.
Code snippet:
Dim target As Object
' target gets properly set to something of the desired type
Dim field As FieldInfo = target.GetType.GetField("fieldName", _
BindingFlags.Instance Or BindingFlags.Public Or BindingFlags.NonPublic)
field.SetValue(target,newValue)
This snippet works perfectly IF target is set to an instance of a CLASS.However, if target is set to an instance of a STRUCTURE, the code does not actually change the value of the field. No error, but the value remains unchanged.And, oddly, if I'm stepping through code, watch the SetValue fail to do anything, and immediately go to the Immediate window and type exactly the same SetValue operation, that works.
Edit:
Per request from Jon Skeet, actual code:
Private Shared Function XmlDeserializeObject(ByVal objectType As Type, _
ByVal deserializedID As String) As Object[code].....
I am making a class that has a property that I want to be of type System.Drawing.Size. I don't seem to be able to reference system.drawing from within my class, and therefor can't set my property's data type to Size. Anyone know how I might do this?
View 2 RepliesThe child nodes are there when first populated but when drives are changed or re loaded a second time, that is when they are missing, so how do I reset the nodes to show child nodes every time
[Code]...
I have a treeview control on my form, i am trying to load an xml into the treeview to show cities/states (example at the bottom of the page)The xml that treeview is loading from looks like:
vb.net
<?xml version="1.0" encoding="utf-8" ?>
<Locations>
<Group name="US States">
[code]....
I am trying to setup a treeview control to display all drives and folders on the PC. So far I can display all drives and folders but the images will not show except rarely. I am using an imagelist with 4 images (index 0-3). The code below is used to load the drives in the treeview control. I have tried using every type of image possible from bmp to png and nothing. I have tried the Appllication.EnableVisualStyles() which I now know isn't needed in vs 2008. I am also having problems with a picturebox in another form that shows nothing but a shadow of the image. I suspect this may be a setting somewhere maybe in vs 2008 but am not able to find one.
Treeview
Dim drive As Integer = 0, dir As Integer = 0
For drive = 0 To oDrives.Length - 1
[code]....
I have this application that users can make exams that contain exercises of different ... whatever. Anyway when student takes the exam he chooses it from a list and then all exercises are loaded from database. I wanted to make loading process faster by loading only first exercise data and putting others in background thread.
Actually in other parts of this application something like that is done but not by me. Basicaly an api class is built around BackgroudWorker and i can use this class to put certain functions of objects to be executed in background. The idea sounds great but in real life there are some problems with it. For example for historical reasons this application uses global functions and reader and uses global connection to Access database which means if in background something is being fectched from data base and you try to fetch from database in main thread then a „reader is already open" error occurs. To avoid this error if im doing something in main thread and want to fetch some data i have to move my function from main thread into background worker function list. And basically this in my opinion stinks cuz you end up with many delegātes, invoked checking and thre result... I was just thinking that there maybe is another way to allow (maybe with events) not put everything in background in case something is happening in bakcground but rather allow bgworker to finsih current thing, then do my thing and then resume bgWorker and not create havoc in code.
Basically i have to classes - exam and exercise that each implement many interfaces (like IExercise, IExerciseResult, IExerciseYesNo, IExerciseMultipleChoise etc.)And then i have DataBase classes like ExerciseDB, ExerciseResult etc. That have functions that preparē the sql params and call sqlHelper functions.And for example when i load up exam i go throug all exercises and call LoadData function that in turn calls ExerciseDB function selectData and then i put the returned data in Exercise object. And this type of thing of course would producē error if i at the same time would try to register the answer in database for another exercise. Ofcourse i could always check and put this in background... but as i said i'd rather want to work with database from both threads.
I'm about to start translating my vb.net application, and I don't want to use the default methods provided by Visual Studio to do so. I need my application to be very light, and it nearly doubles it size to use the resources option.Therefore, I'm planning to use some thing like a class, of which I would have one instance per language. Since I don't want to distribute language files as separate files (I'd rather have them hard-coded), I would like to find an easy way to check if every field of the class is initialized. I was thinking of something like an Interface, where I would do something like this:
Public Interface Language
Dim HelloMsg As String
Dim GoodbyeMsg As String
End Interface
[code]....
It's obviously not the right way to do it (although I could use properties instead of vars), but I was wondering whether the was a way to have the compiler check that everything is translated and warn about it if not.
I have the following Structure within a class[code]...
How do I efficiently use this list?[code]...