If I have a List(Of x) and a List(Of y) is it possible to iterate over both at the same time?
Something like
for each _x as X, _y as Y in List(of x), List(of y)
if _x.item = _y.item then
'do something
end if
next
These lists may be of differing sizes. I am using .Net2.0 which I suspect is my downfall here as I have a feeling LINQ would solve something like easily by joining the lists on there common id.
Lets say I have 30 text fields in a Frame on my form, and I want to set them all to disable (so users can't edit them).Is there an easy way to walk through those fields without having to create an array of text fields?
I.E., in ... VB 6, with an array of text fields, I can do something like this:
For i = 0 to 10
txtfield(x).enabled = true.
Next i
Is there something in VB.NET where I won't have to use an array of controls, something like this (assuming all txt fields are in a frame):
[Code]...
I have a VB class inside which one of the methods accepts an array of forms. For each form inside the array, I need it to traverse all of the objects, check if they are a specific tyoe (input, label, checkbox, etc.) and get the properties of each object. Then, I want to dump these into a text file in the following format:
[Code]...
I have an object called Result<T> that has a constructor which accepts an argument of IEnumerable<T>. I'd like to be able to pass in a datatable if possible.
I tried datatable.AsEnumerable(), but where I bind to the data it was complaining that 'MyProperty' is not a field or property on type 'DataRow' - which makes sense since 'MyProperty' isn't a property on 'DataRow', but it was a column in my datatable.Is there a way to convert a datatable to something that I can pass into the Result object and still have it bind to, say, a gridview?
Below is my code:
[Code]....
NOw, What I want to do is iterate through single file at a time instead of iterate through all files in directory at a time. Here Foreach loop iterate through all files in directory but I wanted to iterate through one file at a time. How can i do that?
I tried using the linq Zip method on IEnumerable but it does not work for more than 2 arrays.Here is an example in Python of what I am trying to do(I got p - nested IEnumerable - and need q - another nested IEnumerable):
>>> l=['a','b','c']
>>> m=[1,2,3]
>>> n=['x','y','z'][code].......
would i do something like "dim txt_whatever as new textbox" or would i do something else?
View 6 RepliesIs there a way to compare two dates (which include time) ignoring the time? I have a 1/1/2009 8:00am and 1/1/2009 9:00am and I just want to know if it is the same day, without any care to what time it is. I know I can convert the date and compare the strings, but is there another way?
View 2 Replieshow do i create sequential files and use objects at the same time. can i get a program and its code if that's possible?
View 1 RepliesI see a couple of previously answered questions about adding an item to an IEnumerable in C#, but I'm stuck when trying to implement the proposed solution in VB.NET.
Option Strict On
Dim customers as IEnumerable(Of Customer)
' Return customers from a LINQ query (not shown)
customers = customers.Concat(New Customer with {.Name = "John Smith"})
The above code gives the error:
Option Strict On disallows implicit conversions from Customer to IEnumerable(Of Customer)
is there a way to retrieve type T from IEnumerable<T> through reflection?
e.g.
i have a variable IEnumerable<Child> info; i want to retrieve Child's type through reflection
IEnumerable interface provides a instance method GetEnumerator that returns IEnumerator type opject .That's okey .But its very hezy to me that how IEnumerable objects are able to work with For Each loop ?When using For Each GetEnumerator method is not called directly from my code .Then from where and how GetEnumerator is called ?Basically my question is that when a class implements IEnumerabel interface then how a distinct behaviour is attached to that class?How it is used with For Each without calling GetEnumerator ?Here is the sample code that i am using :
Public Class Person
Public firstName As String
Public lastName As String
Public Sub New(ByVal firstName As String, ByVal lastName As String)
[code]....
i'm using Enumerable.Except to check if a DataTable in memory is in sync with the table in database.
The background is: this DataTable and other frequently used tables are stored in the Cache of a WebApplication. But meanwhile i'm convinced that this is not a good approach because it's a source for nasty errors that are difficult to reproduce/debug.
Therefore i've created a function that checks if database and memory are in sync, otherwise an error-log will be created. This works perfectly. If there is a row in memory that is not in database, this row will be shown below "Difference in database", the same applies in reverse. But if rows exist in both datasources(the PK idRMA) and some values differ, the log will contain this row in two versions(below "Difference in database" and "Difference in database"). It is not easy to see the differences on the first sight.
Q: Is it possible to select only the properties that caused Except to think that first sequence is not in second?
This is the the complete function(the first lines are relevant):
Public Shared Sub CheckRmaMemoryInSyncWithDB()
Dim inSyncText As String
Dim color As Drawing.Color
[Code]......
I'm trying to use the page control's collection with LINQ. Whereas this works:
dim l = Me.Controls.OfType(Of TextBox).AsQueryable()
the following return an ArgumentExceptionError:
dim l = Me.Controls.AsQueryable()
I used this but did not work :
Dim IENUM As IEnumerable = dat.getDanhSachDongSP
Dim bid as New BindingSource
bid.DataSource = IENUM
Dim dt2 As DataTable
dt2 = bid.DataSource
It show error "cant convert from IEnumberable to datatable"
when you use the object browser to see the features of a sortedlist elementat is not shown , but because a sorted list inherets features of ienumerable it works, cant that be corrected
View 1 RepliesWhile learning to use LINQ in VB.NET, I came across the following:Dim x As IEnumerable = (some LINQ query)
If you can't instantiate an interface, but only a concrete implementation of it, why is this allowed? Is there some difference between doing Dim x as (Type) and Dim x as New (Type)?
I have an IEnumerable(Of System.Data.DataRowView) and would like to set it to be the datasource of a datagridview - however when I try I get no results my IEnumerable variable in the eg below is called xIEnum
DataGridView1.DataSource = xIEnum
However when I go
DataGridView1.DataSource = xIEnum.ToList
it works.... However I want the data to automatically update when I change the underlying datasource that the IEnum is mapped to?
I have the follow Linq query that is in a web application that was converted from .NET 1.1 to 3.5:
dim objListOfFilteredDataRows = from datarows as datarow in objDataSet.tables(0).rows _
where datarows("SomeColumn") = SomeValue
I have the exact same query in an application that was created using .NET 3.5 and the query returns an IEnumerable. However the query in the converted application is returning:
{Name = "WhereEnumerableIterator`1" FullName = "System.Linq.Enumerable+WhereEnumerableIterator`1[[System.Data.DataRow, System.Data, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]]"}
**Edit: When I highlight the expression, the intellisense says that it doesn't know the type of objListOfFilteredDataRows and assumes its a type of "Object". Why is the type not infered in the converted 1.1 application but is infered in the "native" 3.5?**
What am I missing here? How do I convert the "WhereEnumeratorIterator`1 to an IEnumerable?
I've searched everywhere for some example code for this, but I can't figure out how to bind data returned from a function that looks like this to a gridview or dataset.
Public Function GetCompanyList() As IEnumerable(Of BusinessUser)
Return (From companyList In CorporateLists
Select companyList.User).Distinct()
[code].....
how to insert records with dapper-dot-net. However, the answers, while informative, didn't seem to point me in the right direction. Here is the situation: moving data from SqlServer to MySql. Reading the records into an IEnumerable<WTUser> is easy, but I am just not getting something on the insert. First, the 'moving records code':
// moving data
Dim session As New Session(DataProvider.MSSql, "server", _
"database")
Dim resources As List(Of WTUser) = session.QueryReader(Of WTUser)("select * from tbl_resource")
[code]....
Suppose I have an IEnumerable such as a List(TValue) and I want to keep track of whether this list is being accessed (to prevent issues with, say, adding to the list while it is being iterated over on a different thread); I can always write code such as the following:
Dim List1 As New List(Of Integer)
Dim IteratingList1 As Boolean = False
' ... some code ... '
[Code]....
(I realize this code is very arbitrary, but it illustrates what I'm talking about.)
My question is whether there's a better/cleaner way to perform this check than by manually updating and accessing a Boolean, as above. I feel like there must be, but, to my knowledge, there isn't any IEnumerable class with a built-in "I am being iterated over" method or property. And writing a new class that implements IEnumerable and contains such a property seems like overkill to me.
In VB.Net you can easily get the text value of the first child element of an XElement like so:Dim sChildValue = xeParent.<MyChild>.Value()Of course that syntax is not supported in C#, but it produces the same IEnumerable(Of XElement) result as the Elements() method. So we can rewrite the above like so:
Dim sChildValue = xeParent.Elements("MyChild").Value()This Value() extension method is handy because often you are working with small XML documents and you just want the first node that matches. (One thing that annoys me about this method is that it seems to return Nothing/null if the IEnumerable list is empty due to the specified element not being found. To work around this I have created my own ValueOrBlank() method that returns an empty string in that situation instead.)
My problem is that I can't do the same thing in C#:var sChildValue = xeParent.Elements("MyChild").Value(); // won't compile, can't find Value() method
I checked my references/imports and they match the VB.Net project where the same call works. Fortunately I am able to use my custom ValueOrBlank() extension method to accomplish the same thing. But I'm curious as to what's missing in my C# project. I tried right-clicking on the Value() method call in Visual Studio and clicking "Go To Definition" to see if the Object Browser could tell me where the extension method is kept, but it just shows the System.String class. Does that mean this is one of those sneaky VB.Net-only features that the compiler itself supports, like the XML Axis < MyChild > syntax?
The following line is giving me an InvalidCastException when trying to convert to IEnumerable type, even though I have implemented IEnumerable interface. Return New CountryInfo(CountryCodes(i), CountryNames(i)) (also in bold below)
Imports System
Imports Gaia.WebWidgets.HtmlFormatting
Imports System.Collections.Generic
Imports System.Globalization
[code]....
make objects from the ToolBox using code instead of changing existing objects invisible then visible later?
View 7 RepliesI am getting this error, Not sure why it is happening "Error The SqlParameterCollection only accepts non-null SqlParameter type objects, not Int32 objects."I have tried with all sorts of possibilties, now try to enter default data as dummy data,
Using connection As New SqlConnection
connection.ConnectionString = ConfigurationManager.ConnectionStrings("DentalDeviceConnectionString").ConnectionString
connection.Open()[code].....
I have a program like this.
Module Module1
Public Class Mstr
Public Property Prop1 As String
Public Property Prop2 As String[code]....
But it is not working as I expect it to. You can see it from.The DtlsB properties of all three DtlsA objects are having values from last iteration.
I want to let the user input objects to a richtextbox 1 object on each line, and somehow use Random.Next to select pseudorandomly a few objects, the number 'few' inputted in a textbox.
View 9 RepliesPrivate Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Using conn As New SqlConnection("Database=Clinic_Management_System;Data Source=.SQLExpress;Integrated Security=True;AttachDBFilename=|DataDirectory|Clinic Management System.mdf")
Dim cmdRecord As SqlCommand
[code]....
I have a user control that inherits the FW ListView and I need to dispose of two objects when the form's disposing of it's objects. Here's what I've concluded already, am I on the right track?
[Code]...