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.
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
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
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
I have a combo box with a data source. This box shows one column of a table and allows me to select one item.Next, I have an ordinary text LABEL that I need to put text from another column of the item selected above.I tried to set the data binding field of the label, but this grabs only the first row or data and shows the selected column. That is nice, but I can not figure out how to update the selected selected ROW when the combo box item is changed.In this case the combo box lists a bunch of inventory parts. When I select a specific part, I need the change the text in a label to show the manufacturer. (like a sub-form). This same behavior will be used in several other places, but the relationships can cascade.
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?
i tried a lot of variations in my code and even sql statement but still nothing happens.. i really need to do thing messed up project of mine and put all my efforts here.. but i really can't understand why my combo box isn't showing the names of the candidates w/ that designated position.. heres my current code:
constr = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source = " & Application.StartupPath & _ "SSC_Automation.mdb; Persist Security Info = False"
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i am working on a university student council voting system and what i wanted to do is when the voter selected the radio button name "Vote by Party list" automatically the names of all the partylist that are entered in the databse will be listed in the combo box and all the candidates on that Party list will be shown on the individual combo boxes made for each position..
Im trying to pooulate a combo box in vb.net 2008 with information from my access database, but I have no idea how to do thi :S im trying to get it so that the customer names from the database appear in the combo box this is as far as i've gotten for my form load.[code]
What I am "trying" to do is to take a combo box control on my form, and load it up with data from an access db, but I dont want them to be linked so that when I change the combo box to another value it will cahnge record data. From the pics attached I have manage to load the data into the combo box, but the 2 are linked and when I try to change the combo box it creates violations in the database as its trying to change the records.
i am newbie in vb. and i facing a problem in database update into the access database. well, because of my windows have combobox and textbox. i dont have any difficulty in textbox update into access database, but i face a difficulty in combobox. and my combobox have 2 item in it. anyone can teach me? anyone can provide me some coding example and detail examplation. because i am the type who look through the coding and learn form it.
I am using VB 2008 Express to connect to an Access 2007 database. I have a combo box that is populated by the database. When I used the Access report VBA, I used the AfterUpdate() event to calculate a sum and place the results in a text box. I need to know how to do the same operation in VB 2008 Express using the SelectedIndexChanged event of the combo box.
The combo box is called "cboYearMonth" and is populated by my database, this is working correctly.
The text box that I want the calculated results to appear in is called "ExactPagesTextbox"
I have a query in Access called "JobTypeExact_Query" that contains all the pages that I need. What I need to do is calculate the total number of "Pages" limited to the YEARMONTH selected in the combo box. YEARMONTH is a value in every record in this query.
I'm in the middle of creating an application that will be used to input customer information whilst the customer is speaking to someone over the phone. This involves the customer giving the employee information such as name, address, postcode etc and the employee inputting that information into text boxes and combo boxes that are in the application.
What I would like to be able to do is after the customers information is given over the phone, I need to be able to send that information to a database which will probably most likely be done by button click. In this case, I'm using Microsoft Access. I'm also hoping that I can do this within Visual Basic coding.
The database is set out with multiple tables which include a customer table and a ticket table and both have multiple fields such as first name, surname in the customers table. Both of these tables are in use with the information that the customer gives over the phone.
I've already asked on other forums and people are where replying giving me third party programs that I could use to implement this, something I don't really want to do.
I'm in the middle of creating an application that will be used to input customer information whilst the customer is speaking to someone over the phone. This involves the customer giving the employee information such as name, address, postcode etc and the employee inputting that information into text boxes and combo boxes that are in the application.
What I would like to be able to do is after the customers information is given over the phone, I need to be able to send that information to a database which will probably most likely be done by button click. In this case, I'm using Microsoft Access. I'm also hoping that I can do this within Visual Basic coding.The database is set out with multiple tables which include a customer table and a ticket table and both have multiple fields such as first name, surname in the customers table. Both of these tables are in use with the information that the customer gives over the phone.
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?"
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
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 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
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.
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)
Public Shared Function MyValue() As Integer Return 0 End Function Public Sub Code()
[Code]...
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.
