Generating Unknown Object At Runtime
Jan 9, 2010I want to create a new object of a class which is not predetermined before run-time. Something along the lines of:
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Sql - LINQ Generating Bad Query - Error Unknown Column (MySQL)
Sep 16, 2010I'm developing in MVC2 using VB.NET and MySQL and ran into a problem trying to convert a simple SQL query to LINQ. SQL Query:
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Looking at that query its easy to spot whats causing the error. Simply, the most inner query only returns 2 columns, while the query right above it is trying to SELECT 3, thus the Unknown Column Error. So why is this happening? What is wrong with my LINQ query?
Line Of Code Is Generating This Error - Object Reference Not Set To An Instance Of An Object?
Aug 14, 2010with datagridview1
while looping through all the cells
i am trying to allot a cell value to another cell value basing on some conditions
& finally delete one column.my code is as fallows
Dim i, x As Integer
i = 0
x = Me.DataGridView1.Rows.Count[code]....
error i am getting is : Object reference not set to an instance of an object.it is extremely surprising for me the same code has worked nice for me but why & how the same line of code is generating this error.
Generating Controls At Runtime
Apr 29, 2010I was wondering if there was a way to dispose a control that i generated at runtime in a diffrent block of code, The reason why i can't dispose of the control in the same block of code is that the controls settings depend on what the user imputs. For example if i generate the control on a timer tick the code would look like this,
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Generating Multiple Groupboxs At Runtime?
Jun 30, 2010I am not able to generate Multiple GroupBoxes at runtime By using below code. so, plz anyone can help me to rewirte the code....
For i = 1 To ds.Tables("tblprojects").Rows.Count - 1
Dim GroupBox1(i) As New GroupBox()
Dim CheckBox1 As New CheckBox()
Dim RadioButton1 As New RadioButton()
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VS 2010 Generating Code At Runtime
May 14, 2012How can it be done? What I want is to have the program make a string, and then read the string as code. I'm a noob, and it sounds like this should be so easy, but after seeping through this forum, I have found no quick and easy solutions...
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Generating Crystal Report Runtime With Sql Query
Jan 29, 2012on first form one textbox and one button present and in second form crystal report viewer is present in first form textbox i write query and when i click on button i want report in second for with data returned by query
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Addhandler For Unknown Object
Jul 16, 2010The addhandler function works this way: AddHandler Button1.Clicked, AddressOf Button1_Clicked, However, I have an unknown object: Dim o as Object, But I can't add handler for this object AddHandler o.SomeEvent, AddressOf SomeFunction, How do I add handler for unknown objects as stated above?
View 2 Replies.net - Add Handler To Object Of Unknown Type?
Dec 19, 2011I am trying to create a Sub that can take an object and add a load of event handlers for it, but the object can be any one of N types that all have these events. How can I do this? If I just have it as an Object as below AddHandler complains that the event does not exist for Object.
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Copy An Object Of An Unknown Type?
Jul 29, 2010Rather than giving the very specific case (which I did earlier), let me give a general example. Let's say that I have a function, called callingFunction. It has one parameter, called parameter. Parameter is of an unknown type. Let us then say that I wish to copy this parameter, and return it as a new object. For example, in pseudo code, something along the lines of...
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EDIT: Additional Information The first time I posted this question, I received only one response - I felt that perhaps I made the question too specific. I guess I will explain more, I have an ASP page with 10 tables on it. I am trying, using the VB code behind, to come up with a single solution to add new rows to any table. When the user clicks a button, a generic "add row" function should be called.
The difficulty lies in the fact that I have no guarantee of the contents of any table. A new row will have the same contents as the row above it, but given that there are 10 tables, 1 row could contain any number of objects - text boxes, check boxes, etc. So I want to create a generic object, make it of the same type as the row above it, then add it to a new cell, then to a new row, then to the table.
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Object Not Found And Unknown Error
May 9, 2012I have the code below giving me grief because it gives unknown error (0x80005000) when trying to add a user to a second group[code]...
View 5 RepliesError "Object Reference Not Set To An Instance Of An Object - Unknown"
Jun 8, 2012I'm having some trouble with a program i'm making, everytime i try to run the form that runs this code:
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Beep.tone(1000, note, 240)<< this is the line that throws the exception. i have exactly the same code on my main form and it runs perfectly everywhere else, only in the form where it is supposed to be run do i get an exception. Note array is public and i can access it fine from everywhere else, and the custom class beep works fine.
C# - LINQ Query On Object With Unknown Class
May 13, 2011I have an array of unknown (to the current method) class objects. I do know that each class has a property called "Number". I am trying to write a LINQ query where I am looking for the object with the next Number in sequence. AKA, I'm at Number 8, use a LINQ query to find the object where Number=9.
View 5 RepliesChange Properties Of An Unknown Object In Program?
Jul 25, 2009I have a sub that handles when 14 ComboBoxes have their Index changed. I am able to cast the sender of the event, and obtain properties from there. However, after that, I want to be able to change the properties of the actual sender, rather than the cast one.[code]...
View 5 RepliesChanging Unknown Number Of Label Captions Using Unknown Length Array
Oct 22, 2009Using Access 2003 and VB code, I have created a form with a number of labels. The labels will display an employee's names. I have named the labels name1, name2, name3...etc. Using an ADO data set and DCount I have determined the number of names in an Access table (the number of names can vary). What I want to do is for each record in succession to pick the first name and surname from the data set , combine them into a full name (this part has been successful), and then set the full name into the label caption in succession. Example: full name 1 into name1, full name 2 into name2, full name 3 into name3... until all names appear as labels on the form.
I created a counter to and a variable to increment the label number but when I address the caption property of the variable containing the new label (e.g. name1, name2..etc.) it throws an errer at runtime. Here is the code:
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Cast Value Type To Nullable Enumeration Type In Generic Object If All Types Are Unknown At Write-time?
Dec 14, 2011I have a generic Class I'm using to hold information loaded from a database.I have a method which takes a DataRow as an argument, uses the object's known column name and extracts the data from the DataRow, such that:Dim loadData As T = CType(myDataRow("myColumnName"), T))works as my default assignment in most cases.Unfortunately, due to some horrifying design constraints, some of my columns may be null, and may also be taken from enumerations.This means that when <T> is Nullable(Of SomeEnumeration) the above code does not work because I can't cast 0 directly to SomeEnumeration.Zero.Is there some way to check whether <T> is Nullable(Of [Enum])? Or some way to write a method which allows Integers to be cast to Nullable(Of [Enum])?I feel like I'm forgetting something that would allow me to write one of the other of these, but my weak google-fu is turning up nothing.
EDIT: Okay, thanks to dasblinkenlight's answer below, I can detect when this circumstance is occurring, but what I need to do now is to take a type <T> which I know is Nullable(Of SomeClass), get a type reference to SomeClass and then create a new object of type Nullable(Of SomeClass) and assign that to LoadData.My problem was that I had a lot of difficulty in finding any function which would accept baseType as an actual Type.Parse accepted baseType as a parameter, I knew baseType was an [Enum] type because of dasblinkenlight's code, so I was, in this instance, able to code a solution. It's a solution which is very specific to my problem (i.e., T is Nullable(of SomeEnumeration)), but it's a solution nonetheless.
Database Object - Generating Datas In The Database
Jul 16, 2010I am having problem with generating datas in the database. i have an SQl database called Customer with tthe following column (Customer_ID, First Name, last Name, Address, phone and email) I'm trying to filter the data, based on the Customer_ID Enterered in txtCustID.text? I used Parametized Query like this (Select Customer_ID, First Name, last Name, Address, phone ,email from Customer Where Customer_ID= ?) After Clicking Display Button on the form, The corresponding ( First Name, last Name, Address, phone ,email) of the customer is not displayed where i want it?
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Get Runtime Path Of OLE Object?
Apr 16, 2010I've trying to get the runtime path of an OLE Object stored in a database. The code below is used to get the Ole Object (In this case a PDF document).
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Currently, all that's being returned is a pile of bytes of which I have no clue of how to handle.I need to somehow find the path at runtime of this PDF file in order to use it as the value of the 'src' property (string) for my Adobe Reader control.
.net - Runtime Error 424 Object Required?
Jun 4, 2010I get this error in this code:
Private Sub Request_Stuff_button_Click()
Call Main.createObjects
Call My_Control.requestStuff
End Sub
at the 'Call My_Control.requestStuff' line.The 'Main' module looks like this:Public My_Control As ControlObject
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right before the line that gets me the error, x gets the correct value right before the error happens which means My_Control is definitely an object and is definitely not nothing.
Assign A Type To An Object At Runtime In .net Or C#?
Jul 23, 2009I have an object, o, and a type, T. I'd like to use reflection to change object o to type T at runtime without instantiating it.The equivalent at compile time would be:
Dim p as Point = Nothing I know how to use Activator.CreateInstance to create an instance at run time that is equivalent to: Dim p as New Point()
But i don't want to do this. I have no knowledge of the type's constructor parameters and some types don't have a parameterless constructor. eg. Font. So, to sum up, I'd like a way of performing the equivalent of: Dim o as T = Nothing
In case you're wondering why I'm doing this, it's because I'm using a PropertyGrid on a form to edit types. If this is the first time for editing, say, a Font, then passing an uninitialised Font to the PropertyGrid makes the grid display the default values.
I tried 'o = GetUninitializedObject(T)', but the PropertyGrid either wants a properly initialised object or an object, with a defined type, set to nothing.
I've actually solved my particular problem here: how-to-use-the-property-grid-in-a-form-to-edit-any-type
, but i'd still be interested to know how to assign a type at run-time without the use of a wrapper class (which I was lucky enough to be using).
Bind A Runtime Object To Control?
Aug 12, 2010I am developing a fairly large database in VB 2010 as a record keeping. There are 37 tables with some many-to-many relationships in there and some collections too but it all gets loaded into a List of Person object.It is a record keeping database for a youth charity including Personal data, lists of events attended, Medical data, Duke of Edinburgh (UK award scheme) etc The main form is a tabbed form with the linked data from other tables and collection on various tabs
Is it possible to bind a runtime object to a control? if it is possible my life becomes very simple.I can get basic data working with DataSet binding and navigation but the ralationships may prove too fiddly to link as datasets.
Construct Object Names At Runtime?
Jul 15, 2011Is it possible to construct the name of an object (in this case, a Panel control) at runtime?
What I want to do is change the Backcolor of one Panel that is a member of about fifty panels. I can get the string of the name from the Sender in a RadioButton CheckedChanged event. So what I want to do is something like:
PanelName = sender.parent.name & ".BackColor"
PanelName = Color.Red
(I realize that the syntax above is invalid. I'm just using it to try to get the idea across.)
I can do what I need with big, fifty-element Select Case blocks, but the code is so repetitive that I was hoping there was a more elegant way.
Create Object In Forms During Runtime?
Oct 4, 2009Trying to create an application where the objects in a form are created during Form.Load depending on the content in an ini-file.The objects I have in mind are textboxes and labels for a start.
View 5 RepliesGetting A Runtime Object To Be Movable With The Mouse?
Nov 5, 2009TabMenu.Controls.Add(btnOrder)
'btnOrder.Parent = Me.TabMenu
'btnOrder.Location = New Point(300, vertloc + 20)
'btnOrder.Text = "Order"
'btnOrder.Name = intCount.ToString & "OrderButton"
So I have my program make buttons similar to the above, I'm going to have a button created at the point were the cursor is, as long as the location is a valid one. Now I have two questions.
1) I want to use the following code to be able to move around any of the new buttons that I place down on the form.
' a quick TY to Ronald_Hare here on the forums for posting this little snippet, as it does exactly what I want.
Private oControlOffsetPoint As Point
Private Sub Button_MouseMove(ByVal sender As Object, ByVal e As
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2) I also want to be able to change the back color of the button based on a number of boolean flags I will be setting. Is any of this possible without completely mangling things? I'm hoping there are some easy options for setting a button made on runtime to use a number of premade subs or functions.
On a side note: This does not need to be exclusively a button. a picturebox or a text box would probably work just as well for what I want to do, but I like the look I can get with the button atm.
Retrieving A Tag Of An Object Created At Runtime?
Dec 10, 2010My
Public Class Form1
Dim x As Integer = 0
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As you can see, i can retrieve the tag of the button (which is created at runtime) without any problems, i've made a temporary msgbox to show me the value of the tag, just for testing purposes. What i do have a problem with, is retrieving the tag of the individual web browsers, how should i do this?
Next issue, how would i code for my buttons to show the web browser with the same tag as the button that's just been clicked?
Runtime Error 424 Object Required
Jun 11, 2011I am having an issue with a data filled combo box. I can not put my finger on why it is giving me the "run-time error 424 object required" error. The code is simple and the data is there.
Dim sSql As String
Set rsMfg = New ADODB.Recordset
sSql = "Select SourceID, [Source Name Code] AS sc From Source Order By [Source Name Code]"
Set rsMfg = New ADODB.Recordset
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VS 2010 Moving An Object At Runtime?
Jun 2, 2010I am using the following code to move a label at runtime when I mousedown on it and drag it, but how can I make it move freely and randomly around the form without any human intervention?
Private Sub label2_Mousedown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Label2.MouseDownIf e.Button = Windows.Forms.MouseButtons.Left Then
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Adding Custom Object To ArrayList At Runtime?
Jan 5, 2010I am having issues adding a custom object to an arraylist at runtime.
Details of what Im trying to achieve.
My object is Fixture which represents a light. My light has the following properties:
Name, isMover, HighlightValue, UserNumber, Channels.
Channels is a dynamic arraylist which lists all the different channels of the fixture. A channel could be the lights colour or its intensity. A channel has the following properties:
Type, FeatureGroup, Value, Universe, Address, Slots and Offset.
Slots is the same again, breaking down to another ArrayList with more details.
Code:
Private Sub Patchingtest()
Dim TestFixture As New Fixture_Structure
Dim Intensity As New Channel
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Cast An Object To A Type Extracted At Runtime?
Jan 25, 2012I am using reflection to get an object's type, or for this issue an object that has instance properties type, at runtime and then I need to change an existing variable's type into that newly found type. Is this possible? For example, the following code does not work in the line indicated within:
Public Sub DoSomething(x As T, y As T, exp As String)
'This is a instance property on the object of a different type
'i.e. 'T.AnotherType' We need to reflect to find out what type of object
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Change An Object (textbox) Created In Runtime?
Nov 1, 2010I have written some code to generate 10*10 textboxes during run-time.the problem is; I don't know how to access / change them after they are created. after some googling, I found this code to show the text of ie box42;
MessageBox.Show(Me.Controls.Item("box42").Text)
but it gives an error (nullreference exception was unhandled) hereby the code;
For i = 1 To 10
For j = 1 To 10
Dim tb As New TextBox
tb.Name = String.Format("box{0}{0}", i.ToString, j.ToString)
[code]....