User Interface - THE "_Fault_StateChanged" Event Never Fires?
Dec 22, 2009
I have a feature whereby a class in a dll displays a form asking a user to clear a fault on a printer before clicking a button to say "Retry".The users have been just hitting retry without bothering to clear the fault so I am now coding an interlock:The button on the invoked form is disabled until a call is made to an 'enable' method on the form.
This is done with delegate invocation as the events triggering these changes come from other dlls running on different threads.The form's 'enable' method is wired into an EVENT HANDLER handling an event coming in from a different thread (one that monitors an ethernet IO Server).The problem I have is that THE "_Fault_StateChanged" EVENT NEVER FIRES. I suspected the cause was the "ShowDialog" and "DialogResult" technique I have used here, but I have used this exact same technique elsewhere in this application.[code]....
I have a VB .NET form with a splitter control on it, and I want to save its position between program runs. I am currently handling the SplitterMoved event and storing the SplitterDistance. Then on program startup, I set the SplitterDistance to the saved value.
However, sometimes the program resizes the splitter, raising the SplitterMoved event and overwriting my saved distance. I have several splitters over multiple tabs in a tab control, and any time the user goes to a new tab for the first time, the SplitterMoved event fires.Is there an event I can use that will only fire when the user moves the splitter, and not when the program moves the splitter? I tried MouseUp, but when that event fires, the new SplitterDistance is not yet set.
A form has many buttons. One of those buttons contains code to update the TableAdapterManager. One of the many TextBox controls has code in a Validating event handler. There is code to make sure a US phone number is formatted properly.If the user tabs out of the TextBox the Validating code works perfectly and show a message to the user if the phone number is not properly formatted and the focus is place in the offending TextBox.If the user clicks on a button that has code to update the TableAdapterManager the Validating code fires but instead of focus remaining on the offending TextBox, the code in the button Click handler also fires.
I would like to stop the button code from firing.Here is the code for the Validating event of the TextBox:
Private Sub TextBoxPrimaryPhone_Validating(ByVal sender As System.Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles TextBoxPrimaryPhone.Validating ' Make sure the phone is formatted correctly.
[code]....
What additional coding to I need to include so focus remains on the TextBox?
I have a ListView with the Activation property with HotTracking. There appears to be about a 2 second delay between when the user clicks the item and the event fires. Is there a way to get the event to fire immediately upon the user click?
I read data into a DS from an XML file. The user has the ability to "Save" or "Save As" at any time. They can also "Open" an existing file or create a "New" one. (brilliant, don't you think?)
I need to make sure I ask the user if they want to save their existing data (i.e. rewrite the XML file) if the DS has changed from the XML load or from the last time they Saved. On Open, New or exit I have been checking the HasChanges function on the DS. This doesn't work the way that I need. I use AcceptChanges throughout the program to commit values to the DS. This appears to kill the HasChanges even though the DS is now different than the XML file.
Is there an event in the DS that fires when data changes? If so, I believe I can set a flag that can be checked later. If not, is there any other way to track that a DS has changed after the initial XML load? Would reloading the XML into a cloned DS and comparing the two work? Seems like a waste of "time", especially with large XML files, but if it's the only way.
I have a class with two descendent classes (child, grandchild):[code]When a property changes in the Measurement class I raise a OnCrucibleOxidizedMassChanged event:[code]However, the OnChanged sub gets called twice, even though I only assign a value to CrucibleOxidizedMass once.
I have a problem with a ComboBox to select FontStyle. I need to select the font style twice to fire the event in SelectedIndexChanged Event, that means for example to click "Arial Black" twice to set the text to this font.
what event fires when individual textboxes that are bound to a data source using the properties pane gets refreshed? I wish to use this event to populate a few textboxes that are not bound.
The leave event fires twice in this example. Tab order for the form controls is set to combobox1, button1, button3 Private Sub ComboBox1_Leave(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox1.Leave
[Code]...
if I enter 'A' in the combobox1 then combobox1 leave event will fire twice any other entry is Ok since the next control to get focus is button2 (in the normal tab order).It seems that if I try to skip the next control (based on the tab order set for the form), the leave event fires twice.
I've been following a codeproject article on using the interop forms toolkit (basically a way for developers to slowly upgrade their VB6 projects to .net by allowing .net components run in VB6)
[URL]
While the .NET form is working fine in all other testing projects and environments, I've found that the Form_load event is actually firing twice once it's in executing in the VB6 runtime.Not only annoying, its forcing my initialization code to execute twice (causing all kind of problems on the second run).
I have a form for which the form load event only fires one time. When the program starts. It will not fire again until I end the program and restart. I have tried .show and .showdialog, but it acts the same. I have read about form load events loosing the handles, but my code looks exactly like it should.
Here is the load event code PrivateSub frmBilling_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) HandlesMyBase.Load LoadClients() LoadTherapists() LoadCPT() EndSub
Here is the code that calles the form. PrivateSub BillingToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BillingToolStripMenuItem.ClickfrmBilling.Show() frmbilling.show() EndSub
I have a tree view with checkboxes. When a user checks an item in the tree, all items below it in the tree should be checked automatically to match the parent. The same is true is a user unchecks an item. That's been reasonably easy to implement using the after check event:-
Private Sub tvwUserGroups_AfterCheck(ByVal sender As Object, ByVal e As System.Windows.Forms.TreeViewEventArgs) Handles tvwUserGroups.AfterCheck If Not m_Isloading _
I want to change the background color of an element when the mouseEnter event fires. How to make the color of the background darker?? I thought I can use an opacity mask, but it's a gradient, but I need it to be solid. Also it has to be in visual basic code, not in xaml.
I have a BackgroundWorker in a vb.net program that is doing a lengthy data import routine. I want to modify its RunWorkerAsync method so that it fires a custom event on completion of the method. (So that a method in an automated process can respond to the event and resume its work). In a sense I want to 'extend' the RunWorkerAsync method to add an extra line of code--but I can't 'see' the code in the method (to just add the line raising the event) because BackgroundWorker is an MSDN class from Microsoft.The only solution that I can think of is to 'wrap' the background worker class in a wrapper that calls the .RunWorkerAsync method and then raises the event.
Public sub wrapperMethod() myBackgroundWorker.RunWorkerAsync() raise customEvent end sub
Is there a design pattern that I might use? An easy way to address this with the .net language?
PS: Unfortunately, I'm automating some clanking legacy software and backgroundworker is used in many locations, so wrapping the backgroundworker will be a bit of work and may open bugs.
At the top of my code for the form I have the following statements (and some other unrelated ones to):
Dim LastDataRow As DataRow Public Event RowChanged As DataRowChangeEventHandler
When my form loads I run the following line of code:
AddHandler dt.RowChanged, New DataRowChangeEventHandler(AddressOf Row_Changed)
After the form loads I have a FetchData button which connects to the database and brings the records into a datatable object. During this fill operation my Row_Changed event fires (for every record I think) and tries to run DataAdapter.Update(DataTable) (pseudocode) which ultimately fails because I haven't yet created commands. The error I get in my Row_Changed procedure is:
Update requires a valid InsertCommand when passed DataRow collection with new rows.I hadn't even planned to use an InsertCommand at all since I will not be allowing users to insert records from this form. I do plan to allow them to delete or modify existing records, but not insert new ones.run my AddHandler statement after filling the datatable. However, I'm trying to figure out how to rewrite my code so that I can refresh the datatable without closing out the form/application and having to open it up again. I think that's a problem for a separate discussion.
Anyone know why the Mouse_Leave event fires when you don't leave the control with the mouse pointer?Put a large button on a Form so your mouse pointer does not leave it easily.Then try this codeWhen you do, leave the mouse pointer in the middle of the button and then click the button.By the way, if you uncomment the 1st line of code in the Button Click event and comment out the MessageBox, this does not happen.Can someone please explain this behaviour?
Option Strict On Option Explicit On Option Infer Off
Based on our tests primarily done in VB.NET in VS2010 it seems that when you close a WinForm the "RowValidating" event of the DataGridView on that form behaves differently depending on whether the form is MODAL or NON-MODAL. What we did was open the form (MODAL and NONMODAL) and changed a value of a cell and then immediately clicked the "X" to close the form. It looks like the "RowValidating" event DOESN'T fire if the grid is on a MODAL form but it DOES fire when the grid is on a NON-MODAL form. We can't figure out why that is... Is this a known bug in .NET?
I'm working on a design project where I have to use a Graphical User Interface that contains a drag and drop form. It consists of having a window dropped on a wall. Both of them are images to scale. I would like to know what kind of code I would have to use to show the x and y coordinates of one of the points of my window when dragged so when I drop it, I'm dropping in it on the desired coordinate of the wall.
I have set the controls mouse enter and mouse leave events. My problem is that the mouse leave event fires if I mouse over any of the child controls (like the name box for example).What I need is for the mouse leave event to fire when my mouse leaves the entire control, rather than firing when I mouse over any of the child controls. Here are the events as I have them so far:
Private Sub DeliveryControl_MouseEnter(sender As System.Object, e As System.EventArgs) Handles MyBase.MouseEnter Me.removeImage.Visible = True End Sub
Eg. ""vb.net" timer event trigger on purpose". This application is meant to run at all times to download a web page every minute. To avoid freezing the UI, I read that the best solution is to move the code from a While/Sleep loop to a Timer that will be triggered every minute. The problem I have, is that the user must wait for a minute before the event is triggered:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Timer1.Interval = 60000 Timer1.Enabled = True
[CODE]...
Is it possible to force this event to occur instead of waiting for it?
Class Class1 Implements IMyInterface Public Event MyEvent(ByVal sender As Object, ByVal e As MyEventArgs) Implements IMyInterface.MyEvent
[Code]....
I'm sure I can find out what to replace the NotImplementedException parts with but VS is still telling me that the definition is not implemented anyway.
I have an interface class (IUser) which is the interface of class User. Now, i want to put these into an IList but am confused as to how i should declare the IList:Dim userList As IList(Of IUser) = New List(Of IUser) Dim userList As IList(Of User) = New List(Of User) Dim userList As IList(Of IUser) = New List(Of User) Dim userList As IList(Of User) = New List(Of IUser) when instantiating should you always use its implementation; and when using it as a type use its interface?
And when im creating a new user should i use: Dim myUser as IUser = new User?
I am making an interface that has a number of events defined in it. When I implement the interface in a class the events will show up. I want to force a class that implements my interface to also have to make the event handlers too. I don't care where the class raises the event, but I want them to have to define what happens once the event is raised. Is this possible and if so, how do I do it?
I have a Phidget Interface board that has 16 digital inputs. When I trigger an input it fires an event. The problem is that the event fires twice because it fires when the input goes high AND when the input goes back low. I just need it to trigger once per input state change (Input to high and input back to low = 1 button press There are 10 types of people in the world: those who understand binary, and those who don't.
I'm trying to raise an event in a mocked interface. I can get this in C#, but for some pain-in-the-butt reason can't get it working in VB.Net. Hopefully I haven't missed the boat conceptually and all I'm missing is some syntax. This is similar to the code I'm working with:
Public Interface ISendable Event SendMessage(message As String) End Interface ''********** Public Interface IPrintable Sub PrintAnnouncement(announcement As String) [Code] .....
How to complete or correct the line in my test class that begins "sendable.Raise..."? Maybe there is more setup I need to do, but the Moq site didn't seem to indicate this is the case.
