Doesn't Anyone Use Dictionary Member Access Expression
Dec 4, 2009Doesn't anyone use the dictionary member access expression? (a.k.a. the bang operator) If so, in what scenarios? url...
View 1 RepliesDoesn't anyone use the dictionary member access expression? (a.k.a. the bang operator) If so, in what scenarios? url...
View 1 Replieshow do I overcome it? I have created a class and compiled into .dll This code
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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
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i changed a class variable to shared so i can access it in all instances of the class, but it caused an error. what is causing this, and how can i fix it?
Private
Shared img As Bitmap
Me
.img = bgImage
re: Access of shared member constant member enum member or nested type through an instance qualifying expression may not be evaluated I understand that this warning means that you should not reference a shared member via an instance. However, in my test case Test2.t.x("3"), I don't understand why it thinks I'm using an instance, since t is also a shared member. Also, note Test3. See what happens when you change declaration of GetObject() As Object to As Test3. I think I understand the behavior (not eval'd until runtime)
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In Visual Studio 2008, if I do this:
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Does anyone here know how to get the above to work WITHOUT warnings being generated?
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
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I have below installer class to ngen app after installation and I'm getting several errors.
Imports System.Collections
Imports System.ComponentModel
Imports System.Configuration.Install
'This line gives warning: Namespace or type specified in the Imports
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I have installed the SDK 5.1 (using the default install path). My issue is that I'm still not able to use Speech with in my programs. I have Imports SpeechLib. But this is the error I get when I hit return to finish coding:Warning1Namespace or type specified in the Imports 'SpeechLib' doesn't contain any public member or cannot be found. Make sure the namespace or the type is defined and contains at least one public member. Make sure the imported element name doesn't use any aliases.C:\Documents and Settings\Owner\Desktop\ipfinder\ipfinder\Form1.vb19ipfinder
how to fix it so as I can use the Speech in VS 2008?
I have a WPF VB.NET project in Visual Studio 2008. For some reason, Visual Studio thinks that it needs to add anImports MS.Internal.Xaml.Builtinsto every auto-generated XAML partial class (= the nameOfXamlFile.g.vb files), resulting in the following warning:warning BC40056: Namespace or type specified in the Imports 'MS.Internal.Xaml.Builtins' doesn't contain any public member or cannot be found. Make sure the namespace or the type is defined and contains at least one public member. Make sure the imported element name doesn't use any aliases.I can remove the Imports line, but, since this is an auto-generated file, it reappears every time that the project is rebuilt.
View 1 RepliesWhen trying to compile my newly created ClassLibrary class 'Validator' that validates entries made into TextBoxs or MaskedTextBoxs, I get the following error:
Warning 1 Namespace or type specified in the Imports 'System.Windows.Forms' doesn't contain any public member or cannot be found. Make sure the namespace or the type is defined and contains at least one public member. Make sure the imported element name doesn't use any aliases. C:Users erryDocumentsVisual Studio 2008ProjectsMillerClassLibMillerClassLibValidator.vb 1 9 MillerClassLib.
Following is the first part of code in the class:
Imports
System.Windows.Forms
Public
Class Validator
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What can I do to resolve this problem? The classes in this class library will be used to validate forms data input in a number of varied projects.
I just want my program to use random english words in some task and I was wondering if vb.net has access to the OS's english dictionary?
View 2 RepliesI have a Generic Dictionary contained or nested as a child in another Generic Dictionary. I need to be able to access the child dictionary objects by key. When I attempt to do this I get the following error:
"Value of type 'System.Collections.Generic.KeyValuePair(Of String, String)' cannot be converted to 'System.Collections.Generic.Dictionary(Of String, String)'."
So it seems that the contained Generic Dictionary is being returned as a Generic KeyValuePair when accessed via a key as opposed to iterating through the parent dictionary in a For/Each loop.
The first section of the sample works OK (using a key to access a string value in a dictionary).
The second section of the code works OK (iterating through the dictionary values in a For/Each).
The third section of the sample is where the error occurs (using a key to access a nested generic dictionary...see underlined code).
Dim td1 As Dictionary(Of String, String)
For Each thisKey As String In td1.Keys
Debug.Print(td1(thisKey))
Next
Dim td2 As Dictionary(Of String, Dictionary(Of String, String))
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I have a dictionary that I want to access with a key that is the combination of a string (AcctNum) and a date (BalDate).It seems to me the simplest approach is to create the key by simply converting the date to a string and concatenating:MyKey = BalDate.ToString & "|" & AcctNum
I know I also have the option of creating a composite key by writing a separate class and overriding GetHashCode() and Equals() a la this solution. To me, the concatenated string is a simpler, if somewhat less elegant, solution. Am I missing some compelling reason why I should go with the composite key class approach?
This lookup is the crux of the project I am working on, so performance is my main objective (with readability a close second).
I've encountered a problem which challenges my understanding of access modifiers in VB.Net. I have a class declared Friend. If I declare its properties Public, the application works. If I declare them Friend, the application fails.
Before this, I believed that, in a class declared Friend, it would make no functional difference whether I declared the members Public or Friend. I thought class access declarations applied their restrictions to all nested entities, so nested properties declared Public were effectively restricted as if they had been declared Friend. Obviously, I was wrong. Can anyone explain how access modifiers really work, or point me to the relevant documentation?
Here is a more detailed description of the situation: I have a Friend class called StripTask with properties called StripDate, HistorianDate, and TaskText. I have a collection of StripTasks (called _StripTasks) which is used as the data source for a Syncfusion GridDataBoundGrid. The way the binding works, I need to pass the name of a StripTask property to each of the grid columns so each column knows what data to display. It ends up looking something like this:_DataBoundGrid.GridBoundColumns(1).MappingName = "StripDate". When the mapped properties are declared Public, it works. When the mapped properties are declared Friend, the grid is populated with the correct number of rows, but every cell is empty.
As a follow-up question, is it a good idea to avoid things, such as this Syncfusion binding method, which require me to pass property names as strings? It just feels as if I'm inviting trouble.
I'm a newbie to this forum and want to make sure I don't muck things up and irritate everyone as tends to occasionally happen in some forums.I have a very solid background in MS Access (I use it as a front end to an Oracle database and use DAO methods to create native Oracle statements via pass through queries). I am going through the tutorial on VB 2008 Express download the MS site. I have a number of questions that generally have to do with "I did this with VBA in Access, how do I do the same here?"
View 4 RepliesI want to group items from a linq query under a header, so that for each header I have a list of objects that match the header title. I assumed the solution would be to use ToDictionary to convert the objects, but this allows only one object per "group" (or dictionary key). I assumed I could create the dictionary of type (String, List Of()), but I can't figure out how to write it. As an example I have written a simplified version below.
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I have a combobox that is bound to a BindingSource that contains a custom object with multiple Properties.
Is there a way to access a Datamember that is not displayed in the combo box and display it elsewhere. For example, When a user selects a name from the combo box, texboxes (or Labels) populate with Title, PHone, email, etc. All of this data is loaded in the custom object that is bound to the datasource so the info has already been pulled from the db and is in memory.
I've used .NET for a long time but I've never really been sure of this warning :-"Access of a shared member, constant member, enum member or nested type through an instance; qualifying expression will not be evaluated"Whilst this is not causing an issue and I've not really experienced this problem a lot with my own code, converting some code from an old .NET project gives 10's of these errors.
Code:
Protected Function GetContentTypeFromString(ByVal TypeString As String) As MailContentType
Select Case TypeString.ToLower
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After I formatted my laptop and reinstalled Visual Studio 2005, I receive a lot of same error as below message.
"Access of shared member through an instance; qualifying expression will not be evaluated"
If I click the error, it direct me to the line and all 102 error suggest me to add "Windows.Forms." before "DialogResult.OK". Should I add something on "Reference"?
I'm wondering if this is possible. In my Test function below I want to
Check if T is of type BaseClass; throw an error if it's not.
Get the value of SomeText property of BaseClass.
Class BaseClass
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I have created a class with a function in it. I have a collection of data I want to pass back. I tried an arraylist first. Now I am trying to use a dictionary. My problem is that it creates the dictionary ok, but I am only get the last row of data from my
Function GetWeldAuditInfo(ByVal ResourceId
As
String,
ByVal VendorId
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I have the following object:
countDictionary As Dictionary(of Category, Dictionary(of Date, Integer))
The Class has a Enumeration Property. For the purposes of demonstration, I'll call it MasterCategory.I have been trying to get out an object that looks like the following:
groupedCountDictionary As Dictionary(of MasterCategory, Dictionary(of Date, Integer)
The best result I could get was:
Lookup(of MasterCategory, Dictionary(of Date, Integer))
From:
countDictionary.ToLookup(Function(o) o.Key.MasterCategory, Function(o) o.Value)
Which results in a IEnumerable (Of Dictionary(of Date, Integer)) for each MasterCategory value.However, I need that IEnumerable of Dictionary flattened to one dictionary with all the integers summed (total counts) for each date. I then tried to use various selects and group bys (from numerous stackoverflow posts) to "flatten" it, but my efforts have fallen short.
Current Code
[Category Class]
- MasterCategory As Enum
- Name As String etc
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I recall being told by a professor the following is bad practice. But it makes stepping through code a lot less tedious. I'm just solicting comments on pros and cons:
Friend Class MyClass
Private isEmpty As Boolean
Public Property IsEmpty() As Boolean
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I have a custom class called "Time" with the following function, for determining if one Time equals another Time.
Public Shared Shadows Function Equals(ByVal Time1 As Time, ByVal Time2 As Time) As Boolean
Dim x(2) As Integer
x(0) = CInt(Time1.Hour)
x(1) = CInt(Time1.Minute)
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Access of shared member, constant member, enum member or nested type through an instance; qualifying expression will not be evaluated.I know it shouldn't do any harm, just let the compiler skip evaluation, but is it a way of getting rid of this warning?
I created an enumeration in a class library... and compiled it into a dll
Public Enum TestEnum
x = 0
End Enum
I then imported this reference to a windows form project as a referenced dll Public Class Form1 Dim mytestenum As TestPublicEnum.TestEnum Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
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I'm a newbie to threading, trying to learn it as I go. don't make any assumptions and try to explain threading concepts and rules that might seem obvious. I have a Module (Static class) as follows:
Module Main
Private ReadOnly _dbConn As SqlClient.SqlConnection
Public ReadOnly Property DBConn() As SqlClient.SqlConnection
Get
Debug.Print("Accessing DBConn")
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All throughout the application, when i access DBConn on the same thread, it works as expected. howeve, later on I created a background worker that tries to access DBConn and nothing happens, the thread just hanges (the Background worker). I dont get the printout and the application doesnt continue. the background worker thread doesnt continue past that point, and so the thread never exits. I dont get any exceptions, and i Cant debug in Visual Studio (visual studio hangs).I guess its a 2 part question: why cant i access DBConn from the other thread, and why does it hang without giving me a threadAccess exception? also, why does visual studio hang (I'm assuming it hanges because the thread is hanging)?
Please Note: I am not asking about practice. I know I shouldnt be sharing the same connection, rather returning a new connection. in this particular application it is safe since (although i execute it on a background thread) as per the flow of the application, the connection can only be accessed one at a time. I just want to know why it hangs accross the thread.
Here's an example of what I'm talking about...
Public Class Sample1
Public Shared Function MyValue() As Integer
Return 0
End Function
Public Sub Code()
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Me.MyValue gives a warning in VB.NET and (the equivalent code gives) an error in C#. Is there a particular reason for this? I find it more intuitive/natural to access the shared function using 'Me.MyValue' - but I avoid it to keep my warnings at 0. Did someone else just decide 'Nah, it makes more sense to do it the other way' or is there some technical reason I don't understand?
EDIT: I was thinking of it wrong, more like a 'sub class' in OOP. Even if something is declared in the base class, you access it through the instance you have. But that relationship is not the same with shared or static.
Trying to figure out XPath and I have successfully create an XPathExpression that lets me grab the events, but any nested sub groups seem to be unavailable to the query, I can get all the children on the Events group, but the LocationName field I can not access.[code]...
View 1 RepliesI have an access database with several tables. in one of the tables there are three columns named quantity, price and total cost.total cost is an expression of (quantity * price). the expression looks grate in the datagrid etc but when I need to save it to the database
View 1 Replies