In VB.NET, let's assume I have the following Structure:
Public Structure Product
Public ItemNo As Int32
Public Description As String[code].....
How would I define a LINQ Query to Sum all of the Product.Cost values in the List? In other words, what would be the LINQ Query in VB.NET to return the value 120.90, which reflects the sum of all three Product Cost values in a single LINQ Query?
How can i get a structure member by it's string name?
View 1 RepliesI have a question that I really hope someone can shed some light on for me, as this is driving me crazy trying to figure this out. Consider this code..
'declare and allocate
Dim lstNumbers As New List(Of Integer)
Dim nCount As Integer
[code]....
I have problems with array of structures.my structures are like this
structure order
xxxxxxxxxxx
yyyyyyyyyy
zzzzzzzzzzz
end structure
and then I created many array of structures, like this private arrayorder (100) as order
now i need to sort the entire xxxxxx member of the array of the structure with a function, but I dont want to use loops with arrays indexes to access the information. I want to know if there is another method to reference the array and the member of the structure to get the data.
I am using a structure array with multiple member names with 2 types. My question is can you single out one of the member names and add its total? kinda like this...
HTML Code:
structure structureName
dim a as string
dim b as double
dim c as double
[code].....
, I was wondering if it was possible to reference a member of a structure by using a string variable. Here's an example of what i'm talking about:
[Code]....
Now, I know that you would usually reference the value in any of the members by using the following (String1 in this case)
[Code]....
how do I overcome it? I have created a class and compiled into .dll This code
[Code]...
In Visual Studio 2008, if I do this:
[Code]....
Does anyone here know how to get the above to work WITHOUT warnings being generated?
In the following code i get a warning at line 59:Warning 1: Access of shared member, constant member, enum member or nested type through an instance; qualifying expression will not be evaluated.and.. At line 78 I get this Warning:
Warning 2 Property 'SelectedCustomer' doesn't return a value on all code paths. A null reference exception could occur at run time when the result is used.
The program compiles and runs well, but i cant' undesrtand the reason for these warnings. Any Idea ?
1: Public Class Form1
2:
3: 'Form level members
4: Private objCustomers As New ArrayList
[code]....
I have a List "MyList(of MyStruct)"
[vbcode]
Public Structure MyStruct
Public ID as Integer
Public Value as Integer
End Structure
[/vbcode]
At some point I need to update the Value of the member with ID=X, but I'm stuck.
Do I need to search for the index of that member using FindIndex and then set the value like MyList(index).Value=Something?
Or
Find the member itself by using Find, but how would I then set the new value?
VS 2010 [RESOLVED] List(of T) update data of a specific member
View 6 RepliesRegex in VB2008.I have a file system directory that my code is watching. When a file is placed in that directory my code kicks off a processing application. Based on the filename structure, the code will perform different processes. So I need to match the filename structure specficially to get the correct processes to run on that file.My file name structure is: IK2YYYYMMDD_VV.e;where YYYYMMDD is well, the year, month and day. And VV is a verison number from 00-99 If the new file saved in the directory match this structure then I want a TRUE returned. From a filewatcher I get the filename as an "e.Name" (FileSystemEventArgs) variable. My current code to see if it matches the baseline structure is;
Dim IKPred2Match as New Regex ("^IK2.*\.e$") Dim ValidIKPred2Match as MatchCollection = IKPred2Match.Matches(e.Name)I've tried many different regex match patterns, and just can't seem to find the magic one.
I am trying to figure out how to print specific members of a structure when I only have to pass the structure itself i.e.
Dim Point1 as PointF = New PointF(15,30)
Debug.Print(Point1) ' This will output "{X = 15, Y = 30}" by default
I am trying to figure out how I can do the same with my own strucutres, for example:
Dim Point2 as PointF2D = New PointF2D(15,30)
Debug.Print(Point2) ' This will output "ClassName.PointF2D.Point2"
How can I get my structures, when passed to a print statement, to print specific members of that structure by default? P.S. Please give another way other than overloading the .ToString function.
Cannot appear to be able to get this function to not have the above error.Private Function GetIncidentActions(ByVal FromAgentID As Integer, ByVal ToAgentID As Integer, ByVal incidentAction As Integer, ByVal ActionDate As Date) As String
[Code]...
Is there any way of being able to read the structure of a specific directory in tree view. [code]
View 2 RepliesI want to copy files with a specific extension (for example .config or .exe). It should create a structure of nested directories, and then insert each file into a specified place in the directory hierarchy. Ideally I would just specify a parent directory for each file and a parent directory for each directory and it would build it.
I need any existing utility or batch file or power-shell script or C#/VB .Net code to perform this activity.
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'm trying to concatenate two combobox display member values using the following code
Dim CB2DM As String = ComboBox2.DisplayMember
Dim CB1DM As String = ComboBox1.DisplayMember
TextBox8.Text = Join(CB2DM & " " & CB1DM)
I keep getting an error.
I epochly failed creating an array structure. How would I build it like I tried to do with values for each data type.
Structure PovertyGuidelines
Dim Id As Decimal
Dim NumberOfPersons As Decimal
Dim AnnualIncome As Decimal
End Structure
Private Data(20) As PovertyGuidelines
Private Id(,) As Decimal = {{1D, 2D, 3D}}
Private NumberOfPersons(,) As Decimal = {{6D, 9D, 7D}}
Private AnnualIncome(,) As Decimal = {{24000D, 32000D, 27000D}}
I have a user defined structure in a list that I am trying to change the value for in an individual element within the list of structures. Accessing the element is not a problem. However, the compiler complains
"Expression is a value and therefore cannot be the target of the assignment"when I try to update the value.For example:
Public Structure Person
Dim first as String
Dim last as String
Dim age as Integer
[code]....
In what situtations is it best to use reference arguments to return values?
Sub Example(byref value as integer)
value = 3
End Sub
In what situations is it best to return the value (perhaps in a structure for more complex types)?
Function Example() as integer
return 3
End Function
I have created two structures, one named "Product" and the other named "Item". These structures are quite similar but are at the same time quite different from each other. The structure definitions are as follows. Ultimately, I declare arrays in my containing class which access these structures as a type. Their declaration: "Products() as Product" and "Items() as Item". All has been fine and dandy until one day, I go to change the items Enabled() values, and something happens. Not only does it change the Items(index).Enabled(index) value, it does it on the corresponding Products(index).Enabled(index) value, even though it was never specified to do so. Also, nowhere in my coding have i defined this sort of thing to occur. It is rediculous, because I watch it happen. I turn on the watch window, and debug one step at a time, and every time, I watch the Item line step, I look down at the arrays of products and items, and both values have changed. How do I get this to stop, and only change the Item.Enable value??
<Serializable()> _
Public Structure Product
Public Name As String
[code]......
In a public module (codefile) I defined a data structure called db_connection,then declared a variable of that type like so: Public db_con as db_connection I pass db_con to a sub. I expected the db_con structure to be populated with values after the call to the sub. It does not.This is something I have done for years in vb6.What might have changed to prevent this from working?
View 2 RepliesI have a class (using a class rather than a structure only because I can set a default field value for the fields I declare in the class) and I'm using a web service that returns information (demographic information) in JSON. I am using LINQ to get the values of each "entry" from the returned list and in that, I have to parse through and pull out the actual data that I want.Here's how I have it doing right now (just a start, there are 44 of them total, thus my question which will follow the code):
Dim returnedStats = From ljo As Linq.JObject In returnedObject.SelectToken("results")
'
'
For Each stat As Linq.JObject In returnedStats
[code]....
I am having a string in CSV format.http:[code].....I can add new values to it by some mechanism. Everything will be same except the new values will have numeric part = 0. Take example I have this exsiting CSV string
1 , abc.txt , 2 , def.doc , 3 , flyaway.txt
Now by some mechanism i added two more files Superman.txt and Spiderman.txt to the existing string. Now it became
1 , abc.txt , 2 , def.doc , 3 , flyaway.txt, 0, Superman.txt, 0 , Spiderman.txt
What i am doing here is that this csv string is paased into SP where its splitted and inserted to db. So for inserting I have to take the files with numeric part 0 only rest will be omiited .Which will be further then converted into CSV string.Array will look like this
str[0]="1"
str[1]="abc.txt"
str[2]="2"[code].....
So at last i want to say my input will be
1 , abc.txt , 2 , def.doc , 3 , flyaway.txt, 0, Superman.txt, 0 , Spiderman.txt
Desired Output:
0, Superman.txt, 0 , Spiderman.txt
I have a program which grabs the source code of a webpage and puts it into a string. I would now like to search the string for two values.
"video_id": "value 1 here"
"t": "value 2 here"
The problem, is that I don't know the position of the values, and I the values change depending on each webpage. All I know, is the text before the value, e.g. "video_id" and "t:"
Here is my code:
Dim videoid As String = TextBox1.Text.Trim
Dim wc As New System.Net.WebClient()
Dim result As String = wc.DownloadString(videoid)
I have a small database from which I need to select specific data for my Windows Form Textbox.I have a table in a database with a few columns: "ID,Date,Val1,Vla2,Val3,OK" (int, date, int, int, int, bool). There are several rows, but only one of the rows has the boolean value as 1 (or 'True').I would like to select all of the information from that row and write it to different TextBoxes.[code]
View 13 RepliesI'm "cloning" objects in my code. For instance: objClone = objOriginal My question is: Does the assignment operator in VB.NET 1.1 do a member-by-member copy of the objOriginal to objClone or does objClone simply point as a reference to memory referenced by objOriginal?
View 3 RepliesI wish to display values of 2 decimal places whenever this field (datatype = smallmoney) is being read & displayed via a SQL select statement. Is there a simpler way out besides the following example? Im using VS 2008,
CONVERT(varchar, CONVERT(smallmoney, ABS(reading_i - reading_f)), 2 )
I have a datatable contain fId field. I want to update all values for this field to "1" without using loop. [Code]
View 1 Replies