Cancelling The ListView SelectedIndexChanged Event
Apr 13, 2004
I have a ListView that populates some fields whenever the user selects an item. However, if they change the data in the fields and then select a new item without saving, I want to display a message box that warns that their changes will be lost, and asks them to confirm whether to continue. Sounds simple.
Unfortunately, the ListView's SelectedIndexChanged event cannot be cancelled, and it's actually called for each change in the selection. So, for example, if item 1 is selected and the user then selects item 2, the event is called twice: once to remove the selection of item 1, and then to add the selection of item 2. If you go from having one item selected to having five (for example), the event fires to remove your original selection, and then again for each of your new selections - six hits in all.
Obviously, this makes it a bugger to determine when the event should be cancelled and reset back to the original. I obviously don't want my message box appearing six times....
I have a typed dataset that has some required columns. I created a form called by TableNewRow to prompt the user and verify the required selections. If the user cancels the details form I can't seem to get rid of the row that was created, it's stuck there blank.
code excerpt:
Private Sub myDataTable_TableNewRow(ByVal sender As Object, ByVal e As System.Data.DataTableNewRowEventArgs) Handles Me.TableNewRow Dim f As New Form1
I was working on a custom button, in which I had to capture the event of the button, and depending on the certain conditions, either I'll block the event or pass it on the form containing my custom button.[code]Now, I do not have any idea how to block the event and not allow it to pass if the users opts for "No" in the given example.
In an event handler of a tab chaged of a tabcontrol, I call a method asynchrounously, like this:
Private Sub tabDetails_Deselecting(ByVal sender As System.Object, ByVal e As System.Windows.Forms.TabControlCancelEventArgs) Handles tabDetails.Deselecting ' we pass pageindex so that we set the index back in case the validation fails
I have two listviews with many items present. When the user clicks an item in ListViewA, I highlight items in ListViewB. I use the SelectedIndexChanged event of A, loop through the items in B and set some highlighting colors, ensuring visible etc. This works fine.However... it would be nice to allow the user to MultiSelect. The problem here is the when selecting 10 items in A (holding the shift key down), the SelectedIndexChanged event fires 10 times, once for each item added into the selection. This is a real pain since my highlight sub then runs 10 times and it takes 10 times as long.Now... I had a plan to deal with that, I detect the shift key being held down and inhibit the event until its raised. That works fine too.But... if I have 10 items selected, and then I click one new one, so 10 are being deselected and one being selected, the SelectedIndexChanged event fires 11 times. So my situation has not improved. Any ideas how to wriggle out of this?
I am using VB 2010 express edition, using windows form, i set my access database using the database connection wizard, and then use a combobox and bind it to the database using the properties windows, while other fields of database (set in textbox form), i drag it to my form. Running it, the values of textboxes are correct when i changed the value of my combobox. I want to use these values in textbox in drawing circle, whenever i change the value of combobox, the circle will also change using the combobox selectedIndexchanged event, my problem is, the value in textbox does not update in order to draw the circle, i have to use lostfocus or leave event to correct it. I make also a combobox and textbox not using this Ado.net(correct me if im wrong), it is working using the selectedindexchanged event only, what seems be my problem,
On a form I have a DataGridView. Inside this DataGridView i have several columns of which one is combobox and the others are textboxes.The combobox column is populated with values from a MySql database table using a query. So far so good. What i want next is to populate a certain textbox from that DataGridView, automatically after a value from the combobox is selected. When a value is selected from the dropdown list of the combobox, that value is used in a SQL query to find the value that will be displayed in the textbox.All the textboxes and the combobox are inside the DataGridView!)I did this using DataGridView EditingControlShowing event because a DataGridViewComboBoxCell does not have aSelectedIndexChanged event.The value is displayed correctly in the textbox, but the problem is that the value selected from the combobox disappears after the selection, and the combobox remains empty. I need the value to remain in the combobox after it was selected and after the corresponding value was inserted in the textbox!Here is the code for this:
Code: Private Sub test_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 'Populating the combobox
I have combo box selectedIndexChanged events going on but I cant figure out how to get the value out of them so that when i hit the btn_ProjSal that the new salaries show up in the 3 labels. Here is my code. Doing it straight from the selectedIndexChanged event this works..but to get the button to pull the new values from each of those events is my issue.
Public Class Form1 Dim _emp101Sal As Decimal = 10000.0 Dim _emp102Sal As Decimal = 11500.0
I have a list view, of which I want to find the index of... Using the click event, I have no problems at all with this code, but SelectedIndexChanged throws this at me:
I have a ComboBox that contain ProductIDs and a DataGridView that lists Categories which a product can be a member of. My DataGridView list ALL categories, however, it has a checkbox column that get checked when the ProductID is a member of that Category, otherwise it is unchecked. A user may also check or uncheck a category checkbox then save.
The problem is, if a user forgot to save before changing the ComboBox, then his changes on the previous ProductID is gone How can I give the user a chance to either save or ignore the changes done on the previous ProductID (before selecting a new ProductID)?I searched the internet for an answer and I found the following code but it is in C# and I am not sure if it solves the problem or not!
Is there a way to set the selected tab of a tabControl without the selectedIndexchanged event firing? e.g. Here the event fires when selecting myTabPage2 because myTabPage1 is the default:
Asp.Net 2.0 framewrok - VB.Net application I have a UserControl containing a Asp.Net DropDownList.
Things already researched and or tried:
The control gets bound to data on page load inside if not Page.IsPostBack (only loads once) ID proprety is set for control (ID = ddlMyControl) AutoPostBack is set to true EnableViewState on the control is set to true AutoEventWireUp in the UserControl declaration is set to true EnableEventValidation is set to false in the parent page
The control will not fire it's SelectedIndexChanged event no matter what I do.
Can we stop the SelectedIndexChanged Event of combobox at runtime? bcoz when i go to last record my sencond combo is refreshed & It will show 1st Item. but i want to see related item with 1st combo.In the database records are stored with related item.but on frontend..
Amother question is, I want to work with Datagridcombobox. My datagrid contains 3 comboboxes. When i clicked on 1st ,2nd combo should be filled. Same like 2nd third. How can we handle the event of DatagridCombobox??
I have a GridView which you can click on a row and it should call the SelectedIndexChanged method (which updates another part of the page based on which row was selected). I have done something similar to this before and it worked, but I can't seem to get the SelectedIndexChanged part to be called for some reason.The page is held in a master page which has a form runat="server" tag, and an <asp:ScriptManager> tagI am using e.Row. Attributes.Add("onclick", ClientScript.GetPostBackClientHyperlink(Me.gridMessages, "Select$" & e.Row.RowIndex)) to allow the SelectedIndexChanged to fire by clicking anywhere on the row.To check that the code does work apart from that, I added a CommandField with a SelectButton and that successfully fires, but i would prefer to find a solution without having to use that.[code]
Let's say I have a DropDownList of product categories and a ListView of products based on the category selection in the DropDownList. When a user visits the page, there is a possibility of conconrency issue as new product belonging to a new category may be added to the inventory as the user is browsing.When the user selects a different category to view(a SelectedIndexChanged event) and causes a postback, I want the DropDownList to update the list of categories to include the new category being concurrently added and at the same time still able to make a change of selected index.
The method I'm using above is not working. When I select a new item from the drop down list, it works as expected except the message "Loading..." is not showing at all.
I am using VS2008, vb.net, Windows forms project.I have a combo box control on a tab control.The selected value of the combo box is bound to a binding source.The data source of the binding source is a typed dataset.I set the datasource of the binding source when a record is chosen in a data grid control.Since the combo box is bound to the binding source, this should set the selected value of the combo box, and fire the initial SelectedIndexChanged event.Therefore, I remove the SelectedIndexChanged event handler for the combo box before I set the datasource of the binding source, and add the handler again after the datasource is set.
I am using visual studio 2005. i am using webBrowser control to automate third party website.My problem is SelectedIndexChanged event is not getting fired. I used the code.[code]This code is changing the value in combo box but it is not firing the selectedindexchanged event. If i manualy select the item then after selecting a item it shows different message. How should i do it programatically.
send me sample code for SelectedIndexChanged event for Combobox , whn i change value in Combobox through SelectedIndexChanged event then data should be change in Other Combobox and Textbox.B`se i am tring a lot for this but last i am not able to get.In load Event i bind the data in Combobox control .
If All controls bind the same table then how can do code?? and if controls bind different tables then how can do code??
I have a few reasons that I need this to happen, but suffice it to say that when I use the event handler for the RadioButtonList the sender object returns as just the RadioButtonList, and I need more information from the GridView because that's how I can uniquely identify which record my RadioButtonList is tied to.I added an "OnSelectedIndexChanged" property to my GridView but it doesn't fire/handle when I want it to. I'm assuming this has something to do with the way the GridView is designed to work. I also thought about using a hidden field, but I can't add it to the RadioButtonList so it won't help unless it's global. The problem with it being global is that I can't set the value uniquely to the record that has it's RadioButtonList being altered.
Using the following VB.Net simple code to upload files in FTP, a call to WebClient.CancelAsync() doesn't actually cancel the upload.Does someone know why, and what can be done about this?
Private Sub UploadProgressChanged(ByVal sender As Object, ByVal e As System.Net.UploadProgressChangedEventArgs) 'TO-DO: Why is pbar empty? ProgressBar1.Value = e.ProgressPercentage Label1.Text = e.BytesSent & " bytes sent" End Sub
Does anyone know how to cancel a row change in a data grid? What I want is to allow the user to modify a row in a grid. When they try to leave a row after changing it, then prompt them to save the changes before moving to the new row. So far, the rowleave event is working to prompt them to save or not. But I'd like to give them the option to cancel...which should leave them on the original row. The rowleave event, nor any other similar event, appears to have the abiity to cancel the move.
I thought about remembering the row number and just putting it back on that row...but it seems like there probably should be a better way to cancel the row change.
I'm working on this form, and I got 1 text field I am using for validation. If the user doesn't put text inside the box and he clicks the save button it throws a messagebox saying that he didn't put text inside the box, but it still saves the data to the database anyways.
If txtUsername.Text = vbNullString Then MsgBox("All Fields are Required!!") Me.btnSave.Enabled = False
I have the following problem. I have a worker in VB .net (2010) which runs a shell-program. The shell program is a service and output stuff like: Server initializing... Server opening port... more info...
I am able to 'catch' the output of the shell and add it to a textbox (using set text function). And I am able to Cancel the worker by clicking on a stopbutton, however when there is no more output by the shell I cannot stop the worker anymore. At least I suspect that's the case. I've tried checking for endofstream (commented section) but that doesn't work. I've also tried to same code with some test text in stead of 'clsProcess.StandardOutput.ReadLine' and that also works. So I came to the conclusion it must have something to do with clsProcess.StandardOutput.ReadLine being at the end?
How best to cancel/kill a recursive folder copy? I am looping through a number of pathnames in a list box and then recursively copying all files and sub-folders to a backup location. Suppose the user wants to cancel for some reason. I have checked that I can detect a click on my "cancel" button in a timely manner (DoEvents sees to that) but how can I stop the recursive file copy without ending the program? [code]
I am using the code below to login to a softphone. However, the login progess is a long process as there are many things that have to be initialized and checks to be made, I have only put a few on here, as it would make the code to long to post.In the code below I am checking if the CancellationPending if the CancelAsync has been called in my cancel button click event, before doing each check. Is this correct? Also if the check fails I also call the CancelAsync and set the e.Cancel to true.
Private Sub bgwProcessLogin_DoWork(ByVal sender As Object, ByVal e As DoWorkEventArgs) ' ' * Perform at test to see if the background worker has been
I have a Telerik Radgrid containing all the valid usernames and passwords that can be used to unlock functionnalities on my web page. The password is encrypted, so you have to click the row to decrypt and show the actual password. All usernames and passwords can be changed by an admin When the admin presses [ENTER] to submit the new username/password combination (instead of pressing the submit button), the new combination is actually submitted (which is fine).
I've found some unexpected behaviour in my ComboBox, which I'm hoping someone can help me with. If focus is lost by pressing the Return key on a form which has AcceptButton set, then after handling the Validating event and cancelling the validation,the ComboBox will not drop down any more. When you click on the drop-down arrow, the list drops down momentarilly then goes away again To reproduce this, create a new VB.NET Windows Forms application. Drop a Combo Box and a Button onto the default form, then add the following code:[code]....
Run this application, click on the Combo Box, enter some random text (e.g. "asdf"), then press Return. After this, click on the drop-down arrow on the Combo Box.I'm using Visual Basic 2010 Express on Windows 7 Home Premium.
