Forms :: Stopping "automatic" Updating Of Controls With Datasource?
Oct 13, 2011
I'm writing an app that pulls information from a DataSet as a one-way thing (e.g. the datasource populates a listbox, but for selection purposes only -- the user cannot change the list values). My problem is, when I select something from the listbox, all of the other listboxes change too, as if the control is telling the others "Update your contents to display what is in row 5"
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I then use the IDE to bind lstOne and lstTwo (both listboxes) to datInfo, and use the DisplayMember to bind lstOne to colOne and lstTwo to colTwo.When I run and click on a value in one listbox, the other one follows suit. For example if I click on "One Three" in lstOne, lstTwo displays "Two Three". I expect to click on "One Three" then be able to independently set lstTwo to "Two One"
This seems counter-intuitive, so is there a way to do what I'm after from the IDE, or will I have to do it all from code?
I have a goal to have dropdowns populate using a string array as the datasource. Re-binding works well in the dropdown event, but if I make a change to a currently selected line item it won't change until I make the box dropdown again. Is there a way to keep this updated without re-binding the data?
Also, this is one of several dropdowns on an MDI child form. I'd like to make sure they're all synced. For instance if one has "Bob" selected and I change Bob's name to "Chris" I need all the "Bob" dropdowns to change to "Chris". Is there a way to do that without having to cycle through all the windows and call a rebind function?
Finally, I want to know if there's a better way to do it than the way I'm doing it. Since all these children have to be synced, the MDI parent holds the String array as a public property and the children each leech off of it.
I've got a VB2008 application that can potentially generate a table with up to 540 columns. The table is then used as the DataSource for a DataGridView. With column counts in the hundreds the processing time can by over a minute. With all this in single threaded Form code the UI locks up until the DataGridView is loaded. I've taken time stamps of the process to find out where the majority of time is spent.
I'm learning some more VB in my spare time, and I'm making a simple customer database that uses SQLCE. I've got the datasource set up and all that, but for some reason when I hit accept on the form, nothing happens?
I have a wingrid that is bound to a datatable. I create a new asynchronous thread and from that thread make a remote server call passing the datatable. When the server call is completed the wingrid automatically refreshes to show any changes. However, since this is not being done on the main UI thread of the program, we will often get an error where the control goes whilte and a big red X appears in it.
Is there a flag to set the wingrid to not automatically upate when the datasource changes? I would like to turn it off before the remote server call and turn it on again after I am back on the main thread.
I have a sqldatasource with a very simple select statement that should always return one row. I have textboxes on a page that i want to fill with that data from the datasource. how could i do this for textboxes? If there is no data in the database then i want the textboxes to remain empty.[code]....
I have a form that with a list of text boxes. My target is simply binding these controls to an XML file so that whenever the file contents are changed externally, the text box values change dynamically. I will have an external application edit the XML file and overwrite the existing one.
I'm working on a website where we'll be getting a lot of videos to be uploaded. To keep things simple and secure, I'm just writing VB.net windows app to suck all the files in a directory in, allow you to set some options, and start the encode by spawning a new FFMpeg process.
I have a program written with VB.NET 2008 that includes a large number of dynamic controls in a form. When I drag the corner of my form, I want to resize every controls according to the new form size. It works very well, except that the controls are repainted one by one, instead of waiting at the end of my fonction and do a single repaint.
I did a lot of research on the NET without any good results:
- "Form1.DoubleBuffered = true" does not have any effect - "Form1.SuspendLayout" does not have any effect - "SendMessage(Me.Handle, WM_SETREDRAW, New IntPtr(CInt(False)), IntPtr.Zero)" suspended repaints but left the entire window messy.
I am running out of ideas. Here is a sample module to test if your trick works. Just try to resize the form, you will see how long it takes to repaint every control one by one:
I have a query about dynamically added controls to a form. I have a series of buttons which are created and added at run time. I have a two drop down lists and two buttons which are created at design time. Button 1 creates a series of buttons called "Test 1.x" based upon the selection of the two drop down lists. This works fine and am happy with the logic.However.... Button two should remove all the dynamically created buttons from the form.This does not happen. What does happen is that 50% of the buttons are removed starting with the first one. WHen checking the loop it only enters the loop half the amount of times that there are buttons. Very strange. When the loop is run repeatability it will remove all controls. Why will my logic not remove all the dynamically created controls at once? What is wrong with my logic?
I attach two code snippets and the .net file for your consideration.Button method which creates the dynamically created buttons from the two drop down lists and adds to form
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim Count As Integer Dim MaxHours As Integer
My program has two forms which get data from the same data source. After binding controls to tables and fields on both forms, I noticed each form has it's own apparently duplicate DataSet. Is it standard practice for each form to have its own DataSet even though they use the same ConnectionString and connect to the same database at the same time?
I'm having trouble getting controls in non active tabs to update. I have a tab control with 12 tabs. Each tab displays a custom calendar of days for each month. For each of the days I used label controls. Now the trouble im having is when I re-size the window I want the day labels in each tab to re-size accordingly. I have the re-size function written and working but for some reason it will only re-size the active tab. In order for me to have the labels on the other tabs update to the re-size I need to open each tab as to load it then it will update the controls.I've tried putting Application.DoEvents() in my re-size loop but that didn't work. How can I get the other tabs to update / redraw the controls without having to open the tabs first?
I have a form with many controls that are binded to a datasource. when some of these values change, they impact aspects of the form itself like the backgroud color or the title. There is a filter applied to it so it only displays certain records (this is important).when I change something and save the data I need to update the filter to show all the previous records plus the current one.All that works great, but the problem is: saving the data or changing the filter makes the controls take a new value based on the new record and go through the subs that each one have to modify the aspect of the form. This happens because if I save the data first, then the current record does not conform to the filter and all the data in the form changes, or if I change the filter first, we go to the first record of the set.
After that I return to the correct record and everything looks fine, but going to all the changes makes the app halt for a moment.Is there a way that I can stop the controls in the form form updating to their binding data while saving or changing the filter in the bindingsource?
I have created a dynamic form and have added several textboxes controls giving them names such as tb1, tb2 etc. The form is create and displayed, however cannot update the value of the controls.
Private WithEvents gform As New GenerateForm The form is created using the following from click event of a button Dim x As Boolean = gform.myForm("AForm") -- Form get created and displayed x = gform.PopulateForm("a test message") -- The value is passed but not displayed Public Class GenerateForm Dim tbMsg As New TextBox() [Code] .....
I have a function that changes the text in the DisplayMember of a ListBox by first changing the DataTable DataSource and then reloading the datasource.Trouble is, editing any value under the first item causes the DisplayMember values to 'vanish' from sight - they are still there as you can click on them, they just can't be viewed!
I have a custom collection which is derived from a base class implementing IEnumerable and IEnumerator, this collection is populated with custom objects.I'm trying to set the datasource on a ComboBox on a WinForm to use the above collection - but when the code is run the ComboBox is always empty.
The code I was using was this:
Private Sub ViewSources_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load ' declaration Dim sourceCollection As SourceCollection Dim source As Source
Using MSDN documentation on creating Control Arrays in VB.net I proceeded to create a control array based on my UserControl. I modified the code programmatically to Loop through a For-Next loop to create 6 objects using the same UserControl. After creating these objects, I proceed to perform graphics on each control to draw a rectangle of which is in the center of the control by using a Timer_Tick event.
I'm trying to update the UI from a background thread without invoking the control. Mainly because I've tried to do so and it never worked from a class. It worked just fine within the form class, but froze up in the class. I didn't receive any errors, it just lost its multi-threaded-ness.
I'm having a similar problem with using the SynchronizationContext class. I made a quick example to test if this would work how I think it should:
[Code]....
There's very little information on MSDN about this class in general and every example on the web I've seen so far, has nothing to do with classes.
I have a base form and I am trying to get the DataSource of the ActiveControl if the control is a datagridview.What I have so far is:
Dim curControl As Control = Me.ActiveControl Dim ControlType As String = curControl.GetType.ToString() If ControlType = "System.Windows.Forms.DataGridView" Then
I could hard-code in the column names ("WO_Number",WO_CustID","CustLastName", etc...), but would prefer to pick this up dynamically (partly because I want to reuse this code later).
I have a text file that looks like this: 9,1,3,Half,2.20 9,2,9,Half,2.20 9,2,7,Full,3.40 9,2,7,Return,4.20 9,5,2,Half,2.20 How I would sum the last column, all of the numbers in bold, of this text file and then make the result as the DataSource of a Textbox?
I have a module that handles adding controls and populating values on a form. One of the controls is a button (there can be many) which acts as a lookup. For some reason, when I click the Button, it winds up in the btnLookup_Click event and displays the various messages, but it does not update the label (labLookup) text on the form. Am I missing something?
In a windows forms project, I have several combo boxes. The first combo box contains a list of objects. Those objects then have several lists which are used as the datasource's for the successive combo boxes, depending on which item is chosen in the first.
I would like to know how do .net developers manage a large window application with a large number of controls, such as textbox , button, groupbox? I have seen a number of people do it this way : declare the controls as an array and initialize them one by one at run time . In this way it is easy to manage those controls because they can be accessed by array index; but this solution seems to require very good understanding of control's attribute such as its location, font etc. This could be a difficult task if the project is passed on to a less experienced developer and add changes to it.How do you deal with it?
I have a Master List in the DataGrid that displays all the "Monitors" - think of them as Audits (for context). Basically when a user clicks on a row in the DataGrid the TextBoxes, ComboBoxes, CheckBoxes and DatePickers all show the values and the user can edit them there and that all reflects in the DataGrid just fine.How do i go about using the same TextBoxes, ComboBoxes, CheckBoxes and DatePickers to add a new record?
<Monitor.VB> Public Class Monitor Public Property MID As Integer Public Property FileNumber As String
