Variable/property Changed Event In .net?
Jan 3, 2010How can I make an event that is raised when a variable or property is changed (or can I just put the code I would put in an event in the Set section of a property?
View 5 Replies
ADVERTISEMENT
C# - Why Is Attached Property Property Changed Event Only Firing One Time
Nov 27, 2010I have a listbox binded to a list of objects. For each list item I wanted to have a rectangle whose fill color is determined by a few properties of the binded object. So I did the following:
Made sure INotifyPropertyChanged was implemented on my object.Created a class to expose the properties I am interested in as attached properties.Binded the properties of the object to the attached properties of the rectangle Created a style that uses triggers to set the rectangle fill based on attached properties.
This works, but only the first time the property of the object changes. After that, the attached properties do not seem to be receiving notification when the data object's property changes. I have double checked and my data object is raising the INotifyPropertyChanged event.
<Rectangle Style="{StaticResource RecordStateRectangleStyle}"
Width="10" Height="10" Stroke="Black"
local:RecordAttachment.RecordState="{Binding Path=RecordState}"
local:RecordAttachment.IsDeleted="{Binding Path=IsDeleted}" />
[code]....
Raise Event Inside Usercontrol When A Variable Is Changed
Jan 29, 2011I have a usercontrol in my application and inside of this usercontrol I have a declaration:
[Code]....
Handle An Object's Object Property Changed Event In .NET Windows Forms?
Jun 7, 2012I know how to handle a single objects property changed event very easily. I want to handle a objects property changed event that is part of another object.
Given Object:
[ObjectY = Y]
+ Public WithEvents X As ObjectX
I would like to do something like:
Private Sub XPropertyChanged() Handles Y.X.PropertyChanged
Right now I need to create a object that equals the object inside that object and then handle this variable pointers property changed, but that is just annoying.
Catching Property Changed?
Feb 18, 2012Private _pages As New List(Of Panel)
Public ReadOnly Property pages() As List(Of Panel)
Get
[code].....
How To Get DataBindings To Be Two Way When Property Changed
Nov 11, 2010I'm having trouble using DataBindings in a Windows Form / User Control. For example: Create a windows form, place a single text-box on it & place two buttons on it. The code behind the form is:
Imports System.ComponentModel
Public Class Form1
Implements System.ComponentModel.INotifyPropertyChanged
Public Event PropertyChanged(ByVal sender As Object, ByVal e As System.ComponentModel.PropertyChangedEventArgs) Implements System.ComponentModel.INotifyPropertyChanged.PropertyChanged
[Code] .....
If you type something into the text box & press Button1, you'll get a message box with the text of the property in it. If, however, you press Button2 (which sets the property in code) and then press Button1 again, you'll see that while the property was indeed set in the code, the text box doesn't reflect the change.
Updated the code to provide the implementation of INotifyPropertyChanged. This now works as desired.
Find The First Value Of A Variable Changed In A Timer?
Sep 2, 2010I have this problem:I have a vb.net class (visual studio 2010) :
....
Private nowTime As String
....
[code]....
Get Notified When List Of Custom Type Property Changed?
Mar 2, 2011I have a class and one of the properties is a list of a custom class. The caller gets the list and is adding instances of class to the list. How do I get notified that the list has been updated?
Private _list as List(of MyType)
Private _totalField1 as Integer
Public Property MyTypeList As List(Of MyType)
Get
Return _list
End Get
Set(ByVal value As List(Of MyType))
_list= value
_totalField1 = _list.Sum(Function(x) x.Field1)
End Set
End Property
What I'm trying to do is every time a MyType object is added to the list keep a running total of Field1, but adding to the list doesn't use the setter. How can I know when the list has been added or changed?
Add An Event For When A Value Is Changed?
Aug 6, 2009Is there a way I can add an event for when a value is changed, because, I need to add an OnDisconnected() event that detects when the mobjlistener.Connected value has changed...would I have to do a timer, is there a way I can do an event for getting disonnected?
mobjClient = New TcpClient("IP", 5000)
I would rather not add a timer, I would rather have an event that fires when mobjlistener.Connected changes, but if I can't I will go ahead and use the timer instead.The problem I have that I need to detect when this changes is because sometimes I get disconnected for an unknown reason using the TCP Multi-User Chat, it has handlers for disconnected, but whatever is causing the disconnect, it is just not detecting it, so if I could make it so that it will trigger when this is changed, then I can stop the problem I have once and for all.
Object Variable Or With Block Variable Not Set - From Property Get With Bindingsource.current?
May 31, 2012Now I have the need to get a current value from a bindingsource in a property of a user control.In a previous thread I had tracked down the "Object variable or With block variable not set" to the return in the Get block of a property. At the time I was only using the Set so I just commented out the offending code until I needed it.
[Code]...
The error does not occur during a system compile, only upon saving the container object of the user control. As I said the Set works correctly, only the Get causes the error.I would like to know what I am missing/misunderstanding and am open to other suggestions of handling retrieving the current value of a bindingsource in a user control.
Sorting - Change Rank Property Of MyClass By Last Changed Item In OXT
Feb 22, 2011dim oXT As New Generic.SortedDictionary(Of String, MyClass)
[Code]...
Assigning An Object Property Using A Variable As The Property Name?
Aug 4, 2009I want to assign an object property by referencing the property dynamically, with a variable name
i.e.
dim propName as string
staticObjectName.propName = 'whatever
.net - FileSystemWatcher Changed Event Not Being Raised?
Apr 29, 2009I'm working on a Windows Service that watches a few folders for changes, creations, and deletions. It all works well with the exception of one watcher that watches a single file (XML File with Configuration Settings) for minor changes.
I tried taking the Windows Service code and putting it into a simple windows application with start/stop buttons for the filesystem watchers and stepped through it. It never detects the file change of the XML config file. The changes are indeed occurring and the "Date Modified" of the file is updating.
XmlEventReferences = New System.IO.FileSystemWatcher()
XmlEventReferences.Path = "C:XmlReferences"
XmlEventReferences.Filter = "*.xml"
[Code].....
C# - Window Title Changed Event?
Jan 6, 2012If a window, for e.g. Firefox, changes its title, from Firefox to Stack Overflow - Firefox then I want my app to record that Firefox changed its title.Is this possible without the use of a hook and loop (EnumWindows)? If can be only done with a hook, which type of hook?
View 3 RepliesCapture Event When Value In Datagridview Is Changed?
Apr 2, 2010I've been searching all over and I'm either not searching for the right words or it just doesn't exist. I've got a datagridview (dgv) on a form with some textboxes that are databound to different fields in the dgv's datasource. I want to capture an event if someone changes a value through one of the databound controls so I can mark the row as modified. I've been going through the dgv events trying to capture something, but I can't find anything that fires when a value is changed. The dgv is read only, so the values can only be changed through the databount textboxes.
How to I know if someone changes a value in the dgv? Is there a setting in the dgv that will tell me if a row is modified?
Get DataRow That Was Changed In DataBindingComplete Event?
Mar 13, 2012I have a DataGridView that uses a BindingSource to display my underlying DataTable. When the user makes a change to a row in the DataGridView the BindingSource's DataBindingComplete event fires. I'd like to get the DataTable's DataRow that caused this event. How do I do this?
The code below does not return the correct DataRow. For example, when I Fill my DataTable then change row 200 the Current property still equals 0, which always returns the first row in my DataTable.
Private Sub dgvCurrent_DataBindingComplete(ByVal sender As Object, ByVal e As DataGridViewBindingCompleteEventArgs) Handles dgvCurrent.DataBindingComplete
If e.ListChangedType = System.ComponentModel.ListChangedType.ItemChanged
[Code]....
Grid Selection Changed Event
Jul 15, 2009i have 4-5 forms and contains grid and some coding is done on selectionchanged event of grid. eveything is working fine but one of the form has this problem.as soon as i call the form form1.show and it fires the selectionchanged of grid before even it fire form load event. i'm not sure why? i try to debugged it step by step, as soon as form.show command is done the control goes to selectionchage event of grid and at the same time it is working fine on rest of the forms.
View 1 RepliesLimiting A Text Changed Event?
Jun 11, 2009I have an number of text boxes and comboboxes on different forms. I have textchanged events which trigger a msgbox if the user enters invalid data(i.e. the number they enter is to big or to small). Is their a simple way to make the program not call the textchanged event when the form is loaded and the boxes get their initial value? Second is their a way to make the textchanged only be triggered when the user enters data not when the program clears the boxes?
View 3 RepliesScreen Workingarea Changed Event?
Jan 25, 2010i have my form set to 50% of the working area of the Form's screen. I need to know when the screen's workingarea change and resize my form accordingly. Example: the user drags his windows taskbar and hence the workingarea reduces, and as such i wish to resize my form to 50% of the workingarea
View 3 RepliesSelection Changed Event In DataGridComboBoxColumn?
Mar 31, 2012I have a Data grid with DatagridComboBoxColumn , and i want to Fire Event SelectionChanged when user Select any thing From the ComboBox , Do Some operations
View 1 RepliesTrigger A Text Changed Event?
Jan 27, 2009how to trigger a textchanged event. I want to enter data in one text box and have the rest of the data show up after i fill it in. For example I enter someones name and then 3 other text boxes fill in with his height weight and ect after i entered his name.
View 3 RepliesVS 2008 Combobox Value Changed Event?
Sep 27, 2010I am having a problem catching the event that happens when a user selects a value from a combobox. What I was using was ValueMemberChanged, but because I am populating the combobox in code during runtime using SQL and a dataadapter and dataset, this also executes the ValueMemberChanged event, so that makes it difficult for me to know when the user actually changed the value.
View 3 RepliesCall A Button_click Event On Text Changed?
Jul 4, 2011In my project, I am trying to make a button_click event occur when the text of one of my labels is changed.I am using the following code,
Code:
Private Sub Total_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Total.TextChanged
[code].....
Combo Box Selected Index Changed Event?
Jul 1, 2009Here is my code for programming a program that reads from a file called RESORT.TXT
Containing the text:
Barb Allen
604 777 1234
[code].....
Make An Event That Will Fire When Value From A Label Is Changed?
Oct 31, 2011Does anyone know how to make an event that will fire when the value from a label is changed? (In VB.NET)
View 3 RepliesVS 2008 - BindingSource Position Changed Event
May 5, 2009I datagridview and I populate it using a bindingsource. I have the following code in the bindingsources PositionChanged event and it works as I want it to except when I filter the bindingsource.
Private Sub ProductBindingSource_PositionChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles ProductBindingSource.PositionChanged
If (Me.ProductBindingSource.Current IsNot Nothing) Then
Dim dr As DataRow = CType(Me.ProductBindingSource.Current, DataRowView).Row
Dim ProductId As Long = CLng(dr.Item(2).ToString)
Dim ResultId As Integer = CInt(dr.Item(0).ToString)
GetReport2(ProductId, ResultId)
End If
End Sub
The scenario is when I click on a row in my datagridview the bindingsources positionchanged event fires and I load a crystal report. Problem is when I filter the bindingsource, even though the first item in the grid is now different the incorrect report is displayed because the bindingsources position hasn't changed.
VS 2008 Datagridview Cell Value Changed Event?
Aug 2, 2011vb.net
Private Sub DataGridView1_CellValueChanged _
(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) _
Handles DataGridView1.CellValueChanged
[code]....
.net - BindingSource.ListChanged Event Won't Fire When Data Is Changed?
Jun 12, 2012I am trying to get my grid to refresh automatically when the underlying data is updated in the database. Isn't this supposed to work? Or am I missing something? I created a DataTable within my DataSet. Then I created a new form and added a DataGridView (actually I'm using DevExpress' XtraGrid but am trying to get it to work with just the Microsoft controls). I use the menu in the upper left of the grid to set the grid datasource to the datatable in the project data source. This then automatically adds the dataset, BindingSource, and TableAdapter to the form.
[Code]...
Bound ListBox Item Count Changed Event
Feb 22, 2011I'm using a textbox to supply a filter for the datasouce which is bound to a listbox. It works (mostly) with a few exceptions, one being i was to restrict the height of the listbox to the number of entries (upto a maximum number), so a bit like a combobox (which in effect is what I'm writing). One of the problems is when the number of entries changes there does not seem to be an event raised, although the OnDrawItem is called for the items to be displayed (the displayed ones!) Is there anyway to find out (in a derived listbox) when the number of entries has changed in the datasource?
View 4 RepliesHow To Create ' Temporary' Graphics With Text Changed Event
Feb 27, 2011I'm in an upper level industrial engineering class in which we're learning some entry level VB programming. We're working on building a program to solve the travelling salesmen problem (finding the shortest path through a collection of cities while visiting each only once) and I'm trying to add some 'fancy' to it so I can learn some more skills. The basic program is designed to load a bitmap file of a map into a picture box and a text file with the xy coordinates of any city positions. From there, the user can plot the cities with red squares, draw a random tour through the cities, or tour the cities by always visiting the nearest neighbor not yet visited. The modification I'm working on is a method of pointing out a specific city with a black square by entering the city's number (determined from the coordinate file) into a text box.
Private Sub TxtFindCity_textchanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TxtFindCity.TextChanged
Dim ObjFindCity As Graphics = picShowMap.CreateGraphics
Dim City As Integer
[Code]...
So far, the program works, but I want the black squares (but none of the other graphics) that are created to go away once the text box is cleared. As of now they just hang around on the screen until I refresh the entire image with a 'clear map' sub. Any suggestions on how to accomplish this?