I am trying to write a simple linq query from a tutorial I read. But i cannot seem to get it to work. I am trying to display both the address in the attached xml document, but can only display the first one.
<?xml version="1.0" encoding="utf-8" ?>
<Emails>
<Email group="FooBar">
<Subject>Test subject</Subject>
<Content>Test Content</Content>
[Code] .....
I have built a database structure that represents a category tree to help classify some of the data we have stored. The implementation is that each record in the Category table has a nullable foreign key back into the Category table to represent the parent Category of this category (one-to-many), essentially allowing for subcategories within a broader parent level. There is a CategoryMembership table that links a record in the Item table to its respective Category (many-to-many). I have created the DBML for this database, and it has a member access structure that includes the following:
[Code]...
[code]...
In this case, children includes all the Parent elements and all of the Child elements. What's the best way to grab only the direct descendants of <Root>?
Should I write a LINQ query that selects elements where parent = <Root>? Or is there some built-in method I'm missing that can get this for me?
EDIT: I had some confusion between XElement.Elements and XElement.Descendants. As Ruben Bartelink pointed out, XElement.Elements will give me exactly what I was looking for.
I am creating a program which needs to read an online XML file. I am using the XDocument type to do this and currently need help in reading an XML similar to this:
[Code]...
If I had 5 text boxes on a form, TextBox1...TextBox5, is there a method to do something like this?
Dim strFld As String
For intFor = 1 to 5
strFld = "TextBox" & intFor
Me(strFld).Text = intFor
Next
It doesn't like the line of Me(strFld) but I figure there must be a way to reference a field via a variable instead of hardcoding the field name.
I was looking for a way to enumerate String types in (vb).NET, but .NET enums only accept numeric type values.
The first alternative I came across was to create a dictionary of my enum values and the string I want to return. This worked, but was hard to maintain because if you changed the enum you would have to remember to also change the dictionary.
The second alternative was to set field attributes on each enum member, and retrieve it using reflection. Surely enough this worked aswell and also solved the maintenance problem, but it uses reflection and I've always read that using reflection should be a last resort thing.
So I started thinking and I came up with this: every ASCII character can be represented as a hexadecimal value, and you can assign hexadecimal values to enum members. You could get rid of the attributes, assign the hexadecimal values to the enum members. Then, when you need the text value, convert the value to a byte array and use System.Text.Encodings.ASCII.GetString(enumMemberBytes) to get the string value.
Now speaking out of experience, anything I come up with is usually either flawed or just plain wrong. Is there any reason not to do it like that?
As pointed out by David W, enum member values are limited in length, depending on the underlying type (integer by default). So yes, I believe my method works but you are limited to characters in the ASCII table, with a maximum length of 4 or 8 characters using integers or longs respectively.
I am trying to get the AD Properties from a Search that I do. When I do so I get this as a result "System.DirectoryServices.ResultPropertyValueCollection". How do I get the value? I know that it is a collection but everytime I try I am not successful.
Code:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdSearch.Click
Dim resEntry As SearchResult
Dim lstItem As New ListViewItem
Dim currentEntry As New DirectoryEntry
[CODE]...
I'm having trouble with program I'm writing for work. It's basically a GUI for some remote management scripts I wrote a while back.I have a listbox (listbox1) to which loads a list of computers from active directory, which works perfectly and quickly.The problem is that I also want to add to another listbox (listbox2) a list of machines 'currently active' on the network. I can't see an easy way to do this in .net but came up with a logical solution.Basically my thought was to 'ping' all of the machines in the directory listing and use the results to make the list...
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Dim de As New DirectoryEntry()
[code].....
Is there a way to write a single routine that could enumerate a list regardless of the data type? I am trying to write a custom XML serialization class and it would be great if I could enumerate all items in a generic list the same way, regardless if it was of type String, Integer, etc.
View 5 RepliesI have some code designed to locate a specific process based off of its window text, gather the main handle, and then all of the child windows. However, I have run into one problem. I cannot seem to gather all the handles and their respective text. For example, when I test my program and do a handle count on the specific process, it tells me that there are more than 400 handles for this one process. How do I get the handle pointers for this process and also gather the text associated with these handles.I have included my source code for reference.
Code:Public Class Form1
Const GW_CHILD As Integer = 5 Const GW_HWNDNEXT As Integer = 2 Const WM_GETTEXT As Integer = &HD Const WM_GETTEXTLENGTH As Integer = &HE Const BM_SETSTATE As Integer = &HF3 Const WM_LBUTTONUP As Integer = &H202 Const WM_LBUTTONDOWN As Integer = &H201
[code]....
I have some code designed to locate a specific process based off of its window text, gather the main handle, and then all of the child windows. However, I have run into one problem. I cannot seem to gather all the handles and their respective text.
For example, when I test my program and do a handle count on the specific process, it tells me that there are more than 400 handles for this one process. How do I get the handle pointers for this process and also gather the text associated with these handles.
I have included my source code for reference.
Code:Public Class Form1
Const GW_CHILD As Integer = 5 Const GW_HWNDNEXT As Integer = 2 Const WM_GETTEXT As Integer = &HD Const WM_GETTEXTLENGTH As Integer = &HE Const BM_SETSTATE As Integer = &HF3 Const WM_LBUTTONUP As Integer = &H202 Const WM_LBUTTONDOWN As Integer = &H201
[code]....
Is there a way to list the text that appears in each of the tabs of IE8 and Firefox as part of the list of running processes along with the handle.I can list all the running processes fine with their hwnd's but I cant list all of the tabs that are open in either IE8 or Firefox, only the active tab
View 1 RepliesI need to enumerate all the items in an email inbox. However, this code fails
For Each MI As Outlook.MailItem In folderToProcess.Items
'Console.WriteLine("Subject:" + vbTab + MI.Subject)
Console.WriteLine(MI.Subject)
Next
It fails whenever it comes across an item that ISN'T an email (e.g. a meeting request). I've spent the last hour or so trying to find a way of enumerating every item no matter its type. So far all I've come up with is to use the base Object type and then work from there but that's Late Binding and I'd prefer to avoid it if possible.
Has anyone come across this problem before? How can I determine what type of Outlook item it is during enumeration?
As part of my application I am hoping to be able to get the user to enter their IP address and subnet mask which will then enumerate all of the hosts in between which can then be scanned for various open ports/applications installed.
For instance, With a network of 10.91.100.0/255.255.255.252 hosts are valid 10.91.100.1 - .2
How can this be done in vb.net? I would assume also some error checking would need to be put in place to confirm as to whether the subnet mask was valid as well?
I am trying to come up with a good way to enumerate hard disks on remote workstations, possibly including administrative shares, so I can audit key files on them without having to access them via sneakernet.I have domain administrator rights. Security policy prohibits using WMI which would be a great solution.I can retrieve a list of computers using Active Directory, but I need some way to determine what drives are available on each system. Is such a thing feasible? A fellow developer offered some VB6 code from years ago that used WNetOpenEnum, but I was hoping that since we are at .NET framework 4, maybe there's a more elegant / managed way of working with this. I'm keen to use technologies that are more generally supported, such as standard APIs etc. WMI is a great solution but apparently is blocked by default by Windows Firewall, so its availability is not guaranteed.
View 2 RepliesI have need of either enumerating all the managed threads in a application or listen to when a new thread is created. I can not find anyway to do this through searching the web. It strikes me as odd the the IDE can list all the manage threads, but I can't.
If this is not possible, is there clarification as to why this is not possible.
I need to create a shared class in a DLL that will when it receives a signal will stop all the threads currently running, and gracefully exit the application.
Here's my code:
Code: Public Sub ProcessInbox()
Dim oOutlook As New Microsoft.Office.Interop.Outlook.Application Dim oNs As Microsoft.Office.Interop.Outlook.NameSpace Dim oFldr As Microsoft.Office.Interop.Outlook.MAPIFolder Dim oAttachments As Microsoft.Office.Interop.Outlook.Attachments Dim oAttachment As Microsoft.Office.Interop.Outlook.Attachment Dim
[code]....
If I change the following line as shown, it works OK:
Code: Dim oMessage As Object
Is this the best way to get it to work or what should I specifically define the variable oMessage as?
|+--JDMils|+--VB6 & XL VBA+--VB Dot Net 2K8|
given this function:
Public Function Search(ByVal StartIndex As Integer, _
ByVal MaxResults As Integer, _
ByVal AccountNumber As String, _
ByVal LastName As String, _
[Code]....
instead of what I expected:
Select count(*) from remitline where lastname = "smith"
What am I doing wrong building up the where clause? I'm using Castle ActiveRecord 2.1
if there is that much of a performance gain in running a LINQ stored procedure versus a LINQ query?
View 1 RepliesI have a listbox on my xaml form that I bound to a List(Of MyType) property. I populated this list like so:
Dim fields As List(Of CheckableFields) = New List(Of CheckableFields)
Using context As ITIPEntities = New ITIPEntities()
Try[code]....
Now I'm at the point where the user selects the fields they want included in a report and I need to iterate over the required fields. This is my linq query:
For Each checkedField In _requiredFields
If checkedField.IsChecked Then
If checkedField.FieldData IsNot Nothing AndAlso checkedField.FieldData.Trim IsNot String.Empty Then[code].....
Example-I have a person class
Public Class Person
Private _fname As String
Public Property Fname() As String
[Code]...
Forgive my ignorance on this.I have this LINQ Query:Dim ngBikersDataContext As New CarBikeWalkDataContext
bikersList = (From c In ngBikersDataContext.Reg_Bikers _
Order By c.L_Name _
Select New Bikers() With { _
.BikerID = c.BikerID, _
.F_Name = c.F_Name, _
[Code]...
with the error "Overload resolution failed because no accesible 'Select' accepts this number of arguments."
Over the "NEW" I get an error " ')'expected."
We are doing a query against an in-memory collection of LINQ data objects. The wrinkle is that we are ordering by a column in a related table whose records have not necessarily been loaded yet (deferred loading:)
Dim oPkgProducts = _
From b In oBillPkg.BillProducts _
Where b.Successful.GetValueOrDefault(Common.X_INDETERMINATE) = _
[code]....
The pattern I'm trying to avoid is checking if a string (normally a control's text value) is null/empty, and if it is, comparing it using Contains to a field in my data. Obviously the field isn't hard-coded into my extension, neither is the object type.What I've got works perfectly in Linq to Objects, but I get the generic run-time error "LINQ to Entities does not recognize the method 'System.String Invoke(GenericQueryHelper.Customer)' method, and this method cannot be translated into a store expression." when using an entity framework model.
Here's what I have:
<System.Runtime.CompilerServices.Extension()>
Public Function CompareAndFilter(Of T)(source As System.Linq.IQueryable(Of T), expressionField As System.Linq.Expressions.Expression(Of System.Func(Of T, String)), compareTo As String)
[code]....
I want my usage to look something like this:
Dim results = repository.Customers.CompareAndFilter(Function(c) c.FirstName, searchText)
I do need to get this running against a SQL database really, as it is filtering results, so I don't want to be doing that in memory.
How can I convert this code LINQ to SQL in C # LINQ to SQL in Vb.net
[Code]...
How do I add ROW_NUMBER to a LINQ query or Entity? How can I convert this solution to VB.NET?
[Code]...
I'm having trouble porting that last line. I have been unable to locate a VB.NET example. I'm actually not looking for any paging functionality like the example provides, just good old-fashioned Row_Number(Order By X) row index.
How can I convert an object of type System.Data.Linq.DataQuery to System.Linq.IQueryable?I'm working with Visual Basic/Silverlight, and the source code of my query is as follows:
Public Function Get_Cli_Pag() As IQueryable(Of V_Cliente_Pagare)
Dim Qry = From P In Me.Context.Pagares Join C In Me.Context.Codigos On C.Codigo
[code]....
I just upgraded a project from VB 2008 to VB 2010. Before, the project did not use LINQ. I have started implementing it. So, I have updated the target framework from 2.0 to 3.5, and added a reference to System.Core, and imported the namespace System.LINQ to the entire project and also imported System.Data.LINQ into the form I'm working with (because it was not available in the list for Imported Namespaces in the references tab).
It's not throwing any errors now, but my IntelliSense is not working for LINQ stuff.
For example... I write this:
[CODE]....................
Then, if I type S. on the next line, the IntelliSense doesn't grab what it should for S (Only get Equals, GetHashCode, GetType, ReferenceEquals, and ToString, instead of the options I should get like Count, First, FirstOrDefault, etc...). If I Type S.First. then its the same thing, no IntelliSense that lists the available fields for S, just the standard options (Equals, GetHashCode, GetType, ReferenceEquals, and ToString). I should be seeing my column names in my table when I type S.FirstOrDefault.
So any ideas what is going on? When I type the code, for example, MessageBox.Show(S.FirstOrDefault.FirstName), it works perfectly. But it doesn't change the casing of the text (so it would read s.firstordefault.firstname) and no intellisense while doing it. But no errors. BTW - Everything works perfectly when creating a NEW VS 2010 application, it's just my projects upgraded from Visual Basic 2008 that have this issue.
I know that LINQ queries are deferred and only executed when the query is enumerated, but I'm having trouble figuring out exactly when that happens.Certainly in a For Each loop, the query would be enumerated.What's the rule of thumb to follow? I don't want to accidentally enumerate over my query twice if it's a huge result.
For example, does System.Linq.Enumerable.First enumerate over the whole query? I ask for performance reasons. I want to pass a LINQ result set to an ASP.NET MVC view, and I also want to pass the First element separately. Enumerating over the results twice would be painful.It would be great to turn on some kind of flag that alerts me each time a LINQ query is enumerated. That way I could catch scenarios when I accidentally enumerate twice.
I recently switched from VB to C# and have, for the most part, been able to make the transition without too much trouble. Currently I am working on converting a VB.Net program into C# and am having trouble with a couple of code blocks that include Linq.
This is one of the VB.Net lines of code that I am having trouble with:
I have tried to do the same thing in C# like this:
I am getting a compile error on the dt, which says Could not find an implementation of the query pattern for source type 'System.Data.DataTable'.'GroupBy' not found. VS also has issues with the whole into Emailers = group;
I have tried to get this right using examples from my search but have not been able to get it right.