Portable Device Filesystem As FileSystemWatcher Class Path Property?
Mar 6, 2011
I would like to use the .NET FileSystemWatcher class to monitor a folder path which is located on a device currently connected to the host computer and is being managed by Windows Mobile Device Center. The environment is Windows 7 Pro, x64.
When connected to the PC, the device is listed under "Computer" -> "Portable Devices", and I can navigate to its filesystem from there. When setting the "Path" property of my VB .NET app's FileSystemWatcher class object instance, however, it only accepts a valid string-representation of a standard filesystem path (eg. c:somedir hisdir), whereas the address bar of a navigable portable device reads "ComputerPocket_PC";a value which throws an exception at runtime.
Am I able to use the FileSystemWatcher class in this context? How else could I get a PC app to monitor file activity on a handheld device while it is attached?
I have run into a problem with a couple of the "Sync" applications I wanted to create. In both instances, I am trying to connect a Portable Device to my computer and access it using VB.NET. One application would pull the pictures in from my camera, rename them, and put them in folders according to their date taken. The other would place the podcasts I have downloaded onto my Mp3 Player. I have the logic for both so that if I run it on two Windows directories, for example (C:Source and C:Destination) but when I try to access the Portable device using a directory browser, the "OK" button is disabled. Is there any way to access the directories on such a device?
if they choose to use a networked version of my software, I will need the main server doing the authenticating. This is a problem, because from what I understand, it is quite easy to clone MAC addresses. I have looked into using the CPU ID and the HDD ID, but those are not unique, well at least I don't think so. Reason why I say they are not unique is because someone has the exact same CPU ID as me, and the HDD ID changes from partition to partition (same drive). Maybe the HDD ID is a partition ID instead? Anyways, I was thinking maybe I could get the Physical serial number of both the HDD and CPU, but I have not been able to find anything yet.
We have a network share that is used for transferring files between users on a daily basis. Every day at 3:00 am we run a vb6 program to clear the directory of this network share.
I have a very simple class that holds a few public properties - ID, Text, Colour, etc. and a Boolean called 'SelectedItem'. Just like the Checked property on RadioButtons, only one item can have its SelectedItem property set to True within a particular group. Note: there will be several separate groups (lists), each allowed to have only one item with SelectedItem = True.
My first thought was that I would probably just have to handle everything outside of the class, setting SelectedItem to False for every other item in a particular list when another item was selected. But that seems rather inelegant to me. So I've been trying to think of how this might be done within the class. For example: could I perhaps have a private string property called say "GroupName" - set in the New sub when adding a new instance of the class - and then use a private shared method to set every item's SelectedItem property to False, provided the item has the same GroupName as the newly selected item? I would have a go at doing this but I have no idea how to enumerate every instance of a class from within that class, or whether that's even possible. Is it? Or is there another (better) way to achieve my goal? Here is a cut-down version of what I've got so far:
Public Class ResourceItem Public ID As Integer Public Text As String[code]....
As can be seen: instead of instantiating a new ResourceItem and passing that as an argument to the manager's Add procedure, I'm simply passing the details of the new item and the procedure is creating the item from those. I don't know whether this is a good or bad idea - please advise - but I've done it because I couldn't figure out how to make the SelectedItem property only writeable by the manager, so I wanted to avoid having directly accessible objects that could have their SelectedItem property set to True without it deselecting all the other items in the same group. Of course that still leaves the possibility of setting a variable to one of the manager's list items and setting it from there, so I would still like to know how I could prevent that, if possible.
UPDATE: I didn't use the code above in the end, deciding instead to go with Cyborgx37's solution - which seems to work perfectly well for me despite the warnings about best practice. I also realised I would need to use the same class in another scenario where multiple items could be selected, so it was easy to add a Boolean property to the manager to enable that.
Public Class MyColorsClass 'Constructors Public Sub New() 'Empty Constructor
[code]....
However, if the empty constructor was called to instatiate this class then the colortype is not yet set. Therefore, if one accesses the 'IsColorCool' property it will always return 'False'. Now for the sake of this example, I must keep the empty constructor as part of the class.Now I could add some code in the 'IsPropertyCool' to check and see if a ColorType has been defined, and throw an exception if it has not been set, but I don't really want to do that.I also could always move the logic OUT of the property and into a method on the class called 'DefineIfColorIsCool' or something, and make the owness on the caller to make sure the method was called if they want to use the property 'IsColorCool'?
I am writing a class library that envelopes an USB device driver. This device has its own class library, provided by the hardware vendor.
Very often, especially if you handle with old DLL or COM assemblies, there are methods (functions to be correct) that return TRUE if all was OK, or FALSE if any error happen. Often these methods return information about the error in one of their parameters or separately in a GetLastError method or even if in an OnError event.
Now, normally I handle all native .NET exceptions in my class libray handling locally or re-throwing to the client if the error is useful to know. But what to do with all other errors that are hidden in the vendor's methods? (in the true I have no exceptions, but only returned TRUE or FALSE values).
Let's make an example with the method "CONNECT" that connect the client to the USB device.
I envelope the method in this way:
Public Sub Connect() oVendorDevice.connect() End Sub
now if any connection error happen, the vendor's connect method return FALSE. But I do not know why the connection failed. To know why the connection failed I have to call (for example) the method GetLastError that gives me information about the error. (but do not forget that other vendors use other strategies like returning the error in a method's parameter or in a OnError events.
Now, in order to follow a good .NET exception handling strategy I could write something like this:
Public Sub Connect() Dim res As Boolean = oVendorDevice.connect() If res = False Then
I wanted to get your feedback on a design/coding issue. I have a treeview which represents the device tree in device manager. I also have two listviews which display information about the currently selected device on the treeview. I'm only concerned with the first listview at this point. The information displayed in the listview varies depending on the selected device. I'm using the node index to track which device class and device is selected and I pass this into the device class Display method. I hate the idea of a big Select Case statement. Then there is also the dynamic nature of the device tree to consider.
Public Class airplane Private var_num_seats As Integer Private var_num_engines As Integer
[code]....
Obviously, I don't wish that the class Glider has the method "start_engines" neither the property "num_engines". Otherwise, other child classes may have. How can I supress these property and method in child class, not just ignoring (if I can)?
I have procedure (Import) that calls a for a new instance of frmImportData. I also have a class name clsBatch that has a data table property called prpParametersTable.For some reason, I get an error (indicated below with ERROR>>>) when trying to assign prpParameterTable to cv_dtImport2. The error states "Object reference not set to an instance of an object.". Why does this error not happen when I assign dtBP to cv_dtImport1? Both cv_dtImport1 and cv_dtImport2 are equal to Nothing and in my Import procedure dtBP = prpParametersTable.
Public Sub Import(ByVal clsB As clsBatch) Try Me.cv_clsB = clsB
I have three class files, accounts.vb and transactions.vb in addition to my form.vb. I am unable to retrieve a member variable from on class from inside the other. When the combobox index changes, the program loads the correct account (checking or saving) from two different sequential files. I don't think I have the calcBalance procedure in the correct class file. And that is what I am having trouble with. Accessing it to display it. [Code]
This is a bit of a continuation from a previous post for which AtmaWeapon was very informative.
Problem: A parent class has a sub class with various properties. A property of the parent class is a List(of T) with T = the sub class The issue is how to store data in the sub class of the instantiated parent
Some example code (hopefully formatted correctly):
Code: '=========== Class Definitions ============= Public Class courseClass Public Class timeTableClass
I'm looking for a tutorial on how to Adding a list(of Class) or Collection as another Class's Property.What I am after is something like the Columns Collection for the DatagridView control.I would like to add Items in the graphics screen. Where the item list is displayed in the left panel and the selected Item properties are displayed in the right panel.
I have a class that has the following property that is generated by the methods in the constructor.
Public Class clsLoadTables Private _ds As New DataSet Public Property ds() As DataSet Get
[CODE]........................
My problem is that I do not want to inherit this class, but I have other classes that need to access the ds DataSet property. If at all possible I would like to not use inheritance and not load my datatable more than once in the program.
Here is my failed attempt to access the property inside another class that is not inheriting clsLoadTables:
[CODE].........................
How I can access this dataset that I want to load only once in the program from many classes without using class inheritance or a global module?
I know that an interface can contain another interface within it.But;can a class contain another class within it?Can an interface contain another interface within it?
A Problem in accessing a device from VB Windows cannot load the device driver for this hardware because there is a duplicate device already running in the system. (Code 42) This error is because i am using 2 devices of the same company which has the mass usb storage on it and when i install one of the device the other hides. So one is detected the Other is not. It also give a error called designed dragnonacally something...
I have two classes, and for a property in one of the classes I'd like to be able to load it up with an array of the other class. However my attempt at accomplishing this results in a "Object reference not set to an instance of an object" error. I know it's a rookie mistake, but I'm stumpedssist?
My code is as follows: Namespace Parking Public Class garage
bare with me during this silly example. :-) Let's say I have a class like this:
Public Class Animal Public iLegs as int32 ' Number of legs Public bWings as Boolean ' Wings? Yes/No End Class
And another class that inherits the "Animal" class and adds one more property:
Public Class ScaryAnimal Inherits Animal Public iScariness as int32 ' 0-100, how scary is it? End Class
Now, if I have an instance of "Animal" with some values in it, and I decide I want to cast it to a ScaryAnimal for some reason, how do I do that without having to create a new instance of "ScaryAnimal" and copy each property value?Basically I'm looking for a way to do this, without having to write the lines marked with '*** below:
was just wondering in the next versions of vb.net, will the default settings designer in be able to make the onfiguration portable ( which i mean by that the user.config file will be in the app folder ? why i am asking ?urrently my application is portable and i use ini files to store the settings within the application folder and i really wanted to use the settings designer instead ofimplementing my own Settings class using ini or xml files
I was wondering about the possiblity of creating a portable application in vb.net, not for anything specific - more out of curiousity than anything else. The only way that i have thought of doing this is creating an application, grabbing it out of /bin and it would save settings in a xml file or text document/whatever.
I have an ASP.net 3.5 website and I am using vb.net in VWD 2008 Express, I am also using MS SQL Server 2008 Express, I used ajax tabs and a textBox charavters counter control develped by [url]...The database is attached with MS SQL Server Management Studio Express and the files are stored in the SQL default "Data" folder.
The whole project's code and forms are stored in a folder in my E drive.I need to hand the whole project to another coworker who have to finish it, please describe in steps how can i make my website portable (like i can put it all in a folder that he can carry around in his flash disk).
I have an application which pulls xaml page paths from a database. I can then use a navigationservice to navigate to the relevant page when need be. However, I have run into a scenario where I would like to instantiate the page with a specific constructor before navigating to that page.
Is it possible to take a string value such as "PagesMyPage.xaml" at runtime and create an object MyPage? Obviously, I could do this with a switch statement on the page path, but I would like it to be a whole lot more dynamic than that.
I have a simple app (coded in VB 2008 Express Edition) that uses an SQL Server database (in .mdf format) that works fine on my own machine. I created the database in SQL Server on this machine. I added the DB as a data source and it works fine. But when packaged this app (ClickOnce) and installed this app on a different machine the installer tries to download MS SQL Server Express. Obviously this is because SQL Server is a prerequisite and is not installed on the other machine. But just as obvious is the fact that the download will take a long time to complete before my code even starts installing.
My question is this: Is there an SQL Server reference (using Add Reference...) that I can add to avoid this? I suspect the application just needs one or two DLL files from SQL Server. Downloading the whole product seems like overkill. Is there a way I can included the needed files in my app to avoid this long download process?
I'm programatically looking ito a .aspx file and getting the file class name declared in its CodeBehind. For example, when analyzing myFile.aspx I read in its Page Directive and found its CodeBehind equals "myApplicationmyPage.aspx.vb". Then I use the code below:
