DataBound UserControl And PropertyNameChanged Event In .net Winforms?
Oct 30, 2009
I have a UserControl, with a TextBox and a databound property - Value.Value can be any object such as a Color, Array, Font etc.Any time the text changes, the property Value is changed as long as it is valid.Looking at the msdn article: How to: Apply the PropertyNameChanged Pattern , it says I should use the PropertyNameChanged Event patternfrom the control side.Now, If I have DataSourceUpdateMode = OnValidate, then I don't even need to apply this pattern. If, say. my Value property is bound to a colour field in a business object, then after I type red, in the textbox and tab to another field, then any other fields on the form, that bind to the same colour field, are updated immediately.
I'm trying to save some layouts from DevExpress Grid Controls so that users can change the layouts and reload them in at a later use of the control.
My question is this for speed issues I am loading the control via a user control inside of a form. Now my problem is I am creating the control by adding an instance of the control to a panel control inside of a tabbed group control when the tab is made visible and then clearing the control when the control is hidden.
If ClaimsGridPanelControl.Visible = True Then ClaimsGridPanelControl.Controls.Add(New RXClaimsGridControl(ClaimsBindingSource)) Else ClaimsGridPanelControl.Controls.Clear() End If
So inside of the RxClaimGridControl I need to call a SaveLayout method when I am clearing the control. But there is no event, at least that I can find, that triggers when a usercontrol is removed/closed/hidden.
My thoughts for handling the .Clear() would be to raise an event in the parent control and then to handle that event inside of the user control.
Is there some event that I am missing in regards to the removal/closing/hiding of a user control, or is there a better way to do this.
what is the most robust method for adding a empty row (to select "nothing") to a ListBox?
Dim List = Enumerable.Repeat(New TABLE With {.Text = "", .ID = -1}, 1).AsQueryable().Union(From t In mainctx.TABLEs) ddlMangelKategorie.DisplayMember = "Text" ddlMangelKategorie.ValueMember = "ID" ddlMangelKategorie.DataSource = List.ToList
But this has some drawbacks:wordy must explicit write the Type (TABLE in this case), so i cant wrap this in a function have not found an solution, which works with anonymous types I.e. if I add a From t In mainctx.TABLEs Select Text=col1, id=col2 to the query, this method does not work anymore.
I have an WinForms app that requires Name/Address data in lots of places, so I decided it would be a good idea to create a User Control. So far, so good. My problem is this: Let's say that my UserControl presents 2 text boxes (txtFName and txtLName) and txtLName is mandatory. What I want to do is put the validation code, e.g.: Code:If txtLName.Text.Length = 0 ThenMessagebox.Show("Enter a last name")End If
I've got an MDI form with child forms that I'd like to refactor to a single form with a tab control containing child controls, in order to move away from MDI clunkiness. When looking at converting the child forms into child controls (or usercontrols), I do see that I'd lose the FormClosing event, which some of the child forms use.
I can override Dispose to handle some of the functionality, but in some cases I'd like to cancel the closing event. Also, I'd like this event to be called before the control is closed even when the form it's on isn't closing, so wiring the control to the form's closing event isn't an option.
[URL]its a free hoster, so you have to wait 10 seconds.First here's the steps to replicate, then I'll explain what the problem is:
(1) Create a System.Windows.Forms.UserControl and add a button to the bottom-right hand corner. Leave the button anchor as default (top-left). Add some more buttons dotted around so that you can see that they scale correctly.
(2) Add the UserControl to a form in the construtor, after the InitializeComponent call.
(3) Run the form.
(4) Increase the form font size some way (eg click a form button).
All the controls within the usercontrol scale perfectly but the usercontrol itself doesn't. It's width and height are increased by way too much. Look at the margin now between the button at the bottom-right hand corner and the usercontrol.To correct the problem, the usercontrol must be added before the InitializeComponent call.If it wasn't possible for me to add the usercontrol before InitializeComponent, is there any way for me to correct the scaling?
I am working on a wizard form framework that will allow me easily create wizard forms.I have a WizardForm form that has a panel on it. My plan is to dynamically load UserControls into this panel on the form.Each UserControl that is loaded onto the form panel must implement certain properties (allowNavigateNext, AllowNAvigate previous etc.). So I have created an interface to enforce that contract so that any custom user control can be used in the wizard as long as it implements that Interface. So far so good. created my first user control. I implemented the interface. All was good.I went to do the second user control and I realized that this second user control would have the EXACT SAME implementation of the interface as the first User Control. So...I thought...aha...duplicated code...how can I get rid of that.
I have a custom UserControl that contains just one TextBox. When I set the control to Enabled = False, the TextBox is disabled but the control is not (control still fires the Enter event).
How do I ensure that the UserControl will not receive focus?My Enabled Property Looks like this:
Private _Enabled As Boolean = True Public Shadows Property Enabled As Boolean Get Return _Enabled End Get
I have a simple windows Forms application where in I have a usercontrol called "MyControl" derived from PictureBox.
In this MyControl, I have the following code :
Sub New() MyBase.New() Me.BackgroundImage = My.Resources.MyImage 'This is a project resource image End Sub
Now when I drag and drop this MyControl into a form, I get the image and also those stuff. But the problem is that the BackgroundImage is being copied into the Form's local .resx file.So when I look into the form.designer file, I find the following :
My main form has two panels, left docked and right docked. The right side panel has two child panels with top dock and bottom dock settings. The usercontrol is added to the right side top panel. My usercontrol has a panel and a label. The panel is anchored on all 4 sides, the label is anchored on all except the bottom. At runtime I create this usercontrol and set it to dockstyle=fill and then I add it to my top right panel.
With everything set to "fill" I expect that when I add my usercontrol to the panel it will take on the appropriate width and height and pass that info to the child controls (labels) inside of my usercontrol. My problem is that this stretching of the size does not happen when I create my objects during the Load event on my usercontrol. Even though initializecomponent has ran for the usercontrol the panel inside of it (4 corners anchored) has not taken the x/y values of the available space. As a result my usercontrol shows up about 50% of the width I want.
I believe I am on the right path but didnt get it to fire. userControl1 contains a lstBox, it has MouseDoubleClick event doing something inside the userControl. But I want to add something to that event from the form containing the userControl1. So when I mouseDoubleClick the lstBox inside UserControl1 I want to fire the code in my form eventHandler and in the control eventHandler? RaiseEvent?
Public Class myForm 'CodeBehind of form containing userControl1 Private Sub UserControl1_MouseDoubleClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs ) Handeles UserControl1.MouseDoubleClick ds1.clear() [Code] .....
I have a WinForms application (OwnerForm) with some UserControl. When textbox of UserControl is changed, I want to filter content of a OwnerForm. But how can I make it? I don't want to specify OwnerForm inside the user control. I know a solution to add manually handlers for MyUserControl.tb.TextChanged to some functions on a owner form, but I think it's bad way. I'll prefer to have overridable functions, but I can't imagine how to do it.
private panelMain as System.Window.Forms.Panel private usrControl as System.Windows.Forms.UserControl private sub obj_responseMessage(byval envt as Integer) as Handles obj.responseMessage
[code]....
error: An unhandled exception of type 'System.ArgumentException' occurred in system.windows.forms.dll Additional information:Controls created on one thread cannot be parented to a control on a different thread.
I have a user control named "LettersDropControl". It has a dropdown list. I am using this control in a aspx page. When I change the selected item it is not calling the ddlLetters_SelectedIndexChanged event handler? What change I need to make in order to execute the code in ddlLetters_SelectedIndexChanged event handler?
<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="LettersDropControl.ascx.cs" Inherits="MSAJAX1.LettersDropControl" %> public partial class LettersDropControl : System.Web.UI.UserControl { private string selectedLetter; public string SelectedLetter { [Code] .....
Using VB2008 Express I'm getting the following warning on a RemoveHandler statement and subsequent issues since the event is still hooked. Warning 1 The 'AddressOf' expression has no effect in this context because the method argument to 'AddressOf' requires a relaxed conversion to the delegate type of the event. Assign the 'AddressOf' expression to a variable, and use the variable to add or remove the method as the handler.
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.
I created a little usercontrol that looks similar to Visual Studios toolbox. It works great in the user control project, but when I import it to a form the MouseLeave Event doesn't work. The MouseEnter event works fine however. Any idea why only the MouseLeave event doesnt work? I did notice that I have to use the Panel controls MouseLeave, MouseEnter events for things to work correctly. The Usercontrol Mouseleave and Mouseenter didn't work at all.
Public Class vsStyleToolBox Public isPinned As Boolean = False Public isShowing As Boolean = False
I attempt to serialize an object, and it throws an exception as shown below. I assume it attempts to serialize also the UserControl that subsribes to an event of the class I try to serialize. This is not desired. So how do I avoid serializing events?
SerializationException occured:Type 'System.Windows.Forms.UserControl' in Assembly'System.Windows.Forms, Version=2.0.0.0, Culture=neutral,PublicKeyToken=b77a5c561934e089' is not marked as serializable.
Well the title pretty well describes my problem. Here is a little bit more detailed description of my problem: I am building an application with a TabControl, which I populate at execution time with TabPages. In my first version of the code, these TabPages were filled with a children ListView. The ListView was also created in code, using AddHandlers to link it to the DragEnter and DragDrop routines. Everything worked very well... Now as I need some other controls on every TabPage, instead of creating every single control in code, I have created a UserControl containing a ListView and a few Buttons, which I instantiate for every new TabPage. The problem now is that the DragDrop event is not raised anymore
I am using VB.NET together with ADO.NET to create a program. I have set my TableAdapters as needed and bound the correct tables-columns to my comboboxes.My problem though is this:My combobox2 item is bound to a datatable. The table adapter's Fill method (the select command basicaly) includes a public variable in the where clause to fetch the correct results. I ll put some code here to clarify it a bit more.Public Class Frm_inv
Given this illustration and basic code, how do I dequeue and draw the data that has been inserted into the User Control's Preperty queue? The graph/chart will need to show anywhere from 1 to 120 seconds of data, with each second representing electrical waveform data that arrives each second with a variable amount of sample data..The timer interval will have to vary with the amount of incoming data so that it shows a continuously moving waveform from right to left and the rate of drawing keeps up with the amount of data arriving. (so the queue doesn't get backed up)
I'm making a very basic vb.net winforms app, essentially you can drag files into it, and it then uses a batch file to process the files.
It's pretty simple and everything is going to plan so far, it accepts the right files, it uses the batch file to process them and the batch file does what it is supposed to.The only problem is that I don't know how to hook into the Exited event that can/should be raised by the batch file process when the process completes...
I want the DOS window of the batch file to remain hidden while it is running, so I have used ProcessStartInfo to specify the batch file, then set the WindowStyle property of the process to ProcessWindowStyle.Minimised, then used System.Diagnostics.Process.Start(myBatch) to start the process at the appropriate moment.
This is fine, it works and does what I want. However, the only way to tell when a process ends is to use the Exited event. But the Exited event apparently only works with a Process not a ProcessStartInfo. I could switch to use Process instead but then I couldn't (AFAIK) run the DOS window minimised... I've only been writing .net for a few days. This is how I'm running the batch file:
Dim myBatch As New ProcessStartInfo("C:\batchFiles\test.bat") myBatch.WindowStyle = ProcessWindowStyle.Minimized system.Diagnostics.Process.Start(myBatch)
I already have KeyPreview set to true in the form properties I'm working on a small program, and I'm having a problem where it seems that some of the controls on it inside groupboxes are not triggering the KeyDown event on my form when I press and release any arrow key, just the KeyUp event. Specifically, I've enabled KeyPreview on the form, and set breakpoints on e.SuppressKeyPress = True in both subroutines, and only the one for frmMain_KeyUp hits the breakpoint.
I added in the two GroupBox events hoping that might mitigate the issue, but no such luck. However, I have a custom control on the form that is specifically coded to ignore these keypresses, and the code works as expected on it.
Private Sub frmMain_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles Me.KeyDown, GroupBox1.KeyDown, GroupBox2.KeyDown e.SuppressKeyPress = True Select Case e.KeyCode
[code]....
The code in the user control that "ignores" keypresses is as such:
Private Sub TileDropDown_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles Me.KeyDown If e.KeyValue = 40 OrElse e.KeyValue = 38 OrElse e.KeyValue = 39 OrElse e.KeyValue = 37 Then e.SuppressKeyPress = True End If End Sub
In WinForms I could handle the Validated event to do something after the user changed text in a TextBox. Unlike TextChanged, Validated didn't fire for every character change; it only fired when the user was done.Is there anything in WPF I can use to get the same result, an event raised only after the user is done changing the text?
I have used the below code but its not showing the msgbox. What is wrong with this code ?
Private Sub frmSimple_Disposed(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Disposed Dim result = MsgBox("Are you sure you want to Exit ?", vbYesNo) If result = DialogResult.Yes Then me.Close() End If End Sub
I have a Windows form UserControl that receives electrical signal waveform data into a 128 element byte array Property every 1,000 ms.
I would like to have the Paint event draw a a subset of the 128 sample points of the array every 100ms (12-13 graphic.drawline operations) to simulate a rolling waveform display such as one would see on an oscilloscope or a medical monitoring device. Is it possible, and if so, how would I set the paint event handler to fire every 100 ms?
