I have created a UserControl using a DevExpress XtraTreeList. Basically in this user control I am using inventory Items. which are more than 30,000. Now when I load the complete table in my typed DataSet it takes almost 6-8 seconds.
The purpose to build the usercontrol is reuseability. So that we can use it in other parts of the application.
Now I am using this UserControl in a Winform, where this usercontrol is place in the left hand side on the form where it will be used as a Menu. The user is suppose to click its desired item by expanding the nodes and when the nodes is selected and then its further details will be fetched and will be displayed in the from. So far so good.
Now the reals issue is that in the same form along with other controls, we have a Devexpress XtraButtonEdit(build using a textbox and a button on the right handside). This buttonEdit is displaying the currently selected Item(from the treeMenu UserControl) code in its textbox, when we are clicking the buttonEdit button then we are loading another form as a model and displaying the same UserControl (XTRATreeList from DevEpress). The only issue is that when I am laoding this new form as a model. The tree again takes time to load which looks bit awkward.
To rectifiy this issue, I am trying to implement the Background worker thread, but bit confused that where should I implement that backgroundWork. In the User Control or in the form.
If I implement that Background worder in the UserControl then how can I access this BackgroundWorker thread and execute it on the main Form where I am using the UserControl on the left hand side as a Menu. Actually what I want is when user clicks the ButtonEdit control and the form loads, it should load like a flash or max in 2 sec....please help.... and execute it.
I hope that ppl will understand my issue.
If somebody finds any difficulty plz let me know....
Regards,
You don't have to "access this BackgroundWorker thread and execute it on the main Form".
A user control could contain its own Bgw. You nee a synchronous method (on the UC) to start it. Then handle the completed (and mayb progress) events inside your UC.
But the data won't load any faster, you only unfreeze your main GUI.
If the delay is caused in the code that loads the tree, then you should "thread" that part. I would recommend reading this sample chapter from C# in a Nutshell: http://www.albahari.com/threading/. They cover C# 4.0, but you should be able to apply most of the concepts to C# 3.0 if that's what you are using.
Related
I have a GMap.NET control on my main form, and then I have a second form that will show when the user clicks on a button. The problem is, that when the user leaves the second window and hovers over the GMap control from the main form, the main form comes to the front. This does not happen when i hover over the rest of the main window with the second window on the front. Also I have another form that will show while the program searches for some data, and this one will also disappear when the user hovers over the map.
I hope I explained it well enough, basically when I hover over the map the main window comes to the front. And it does only happen when there is another form of my project in front of it, not when there is any other window like firefox or something in the front.
So my question is: why does this happen and can I change this behavior? Is it a standard of the GMap.NET control? I am using the Version 1.7.0.0 control btw.
you must use
GMap1.DisableFocusOnMouseEnter = true;
i added this code to my program and problem solved.
It would help to see some code as to how you are showing the forms, but it sounds like you are doing something like secondwindow.Show() instead of secondwindow.ShowDialog(), and then an event from GMap for OnEnter is doing a Focus().
Then, when you have the "other form" in front of it, it's opened in a way that will restrict access to the parent form (ShowDialog(), etc).
In my form_load I have a mysql connection that loads data in a datagrid, when starting my application it will first try to load the mysql database and after its done it will load the form/interface with all the controls.
This leaves the user the impression nothing is happening, how can I first load the form/interface with all the controls and then my mysql database?
I would say, 3 approaches
1 - Separate Splash screen
2 - On-Form "splash screen" - first thing you do on form.load, is Me.Show(), then show a message, something like "Please wait while data is loaded". Progress can be shown to users as well using Application.DoEvents which will refresh your screen.
3 - Background worker thread. Using it, you can actually give user progress updates. That will leave your form completely responsive. http://msdn.microsoft.com/en-us/library/cc221403%28v=vs.95%29.aspx
Move your code to Shown event or OnShown overridden method. this will allow your form shown to user before it loads grid.
You should move your "Database calls" to worker threads as well.
protected override void OnShown(EventArgs e)
{
//Delegate the DB calls to worker threads here
//everything will be smooth then..
base.OnShown(e);
}
There are two ways to approach this situation. You need to pick the approach that best suits your needs.
Approach 1: Create a splash screen. A splash screen is a small window that opens up and usually had product info and a message like "Initializing...". You can see this in a lot of applications, such as Microsoft Office. You can see how to make one by looking at this article.
Approach 2: You will need to make your load data happen in a separate thread then your UI. You will need to load your data in the separate thread and bind it to a list of some sort temporarily, then after its done, bind the list to your Datagrid
Use other thread for loading data from mysql. It's loading form first, but not displaying it until code has finished work.
new Thread(new ThreadStart(LoadDataMethodHere)).Start();
You can use Form Shown event.
Alternatively you can use a different thread to connect to database and show data or use a timer.
good sirs!
I've been messing around with the next scenario:
First, I have a webform structured as a WebForm containing a DevExpress ASPXPopUpControl and some other controls. Inside the PopUpControl there is a UserControl (lets call it ucA) containing some other controls and a UserControl (called ucB) that contains a cursed ASPxHtmlEditor (added because it's a new requirement).
When the user hits a button on main webform I show the PopUp (originally was a jQuery dialog but since HTMLEditor messes up with jQuery I've been forced to break the standard and use the popup) which contains the ucA. The user fills some fields in ucA and hit the save button. After user hits, I save some dataz and at this point I need to recover a textbox value placed in the webform.
I'm using Parent.FindControl["myTextBox"] but it considers the popupcontrol as parent. When I was using jQuery (before implementing the editor) it worked like a charm.
I feel it's something trivial but thrust me when I say that this stole many hours of research.
Thanks in advance.
EDIT I forgot to mention that I want to look for another UserControl at main webform. This uc its used to display core messages to the user so when he hits the save button, save happens, popup is closed and i look (Parent.FindControl("myUCMessageBoard")) from the ucA for the usercontrol to display a "Transaction complete" message.
I'm thinking you're going to have to do something a little hacky, by using ViewState. If I understand correctly, you are trying to get access to a TextBox's Text on the Web Form, from a UserControl nested within a PopupControl (so you can't traverse all the way up to Web Form Level).
So, what I'd do at some point in the process is store the text in a ViewState variable that you can access from the User Control. It's not optimal, but since you're already hacking to get it to work, what's a little more hacking?
You should expose all controls from ucA as properties, then look for the control inside the DevxPopup the same way you doing. Given that all the controls that you need at the ucA has properties to access them, you could do all the logic you need!
Example:
public ucA : UserControl
{
public string myTextBoxText
{
get
{
return ((TextBox)Controls.FindControl("myTextBox")).Text;
}
}
/*And lot of controls*/
}
Then you looking for the popup at the Form
var ucA = (UcA)Form.Controls.FindControl("myPopup").Controls.FindControl("myucA");
ucA.myTextBoxText = /*Do stuff here with the text*/
Hopes this help you!
I want a form to be shown modal every time it is opend. Since I can not change the way it is created and opend. I wondered if it is possible to make the form stay on top from within the forms class.
One opportunity is the TopMost property. This works in general, but if I display the form while the main thread is waiting for it to close, the form will stay on top even if I change the application(to a browser for example). So no matter where I am, the form is still displayed.
Another issue which I came across is that in some cases it is adopted by the parent form which then might block other windows or popup messages.
I was thinking about a hook to the OnLostFocus event to get it on top again, once the focus is lost, but I'm not sure if that is a good idea ...
Any helpful thoughts about it?
Edit
Due to the comments I will extend my description, Here is the real use-case
We are using the Devexpress's SplashScreenManager which is able to show a certain form as a WaitForm. Since the WaitForm is not intended to be shown modal(see on the Support Center), we are looking for a way to do so.
We can not change the way the form is shown, because this is done through the SplashScreenManager. The WaitForm is shown both from the main thread, as well as from certain backgroundworker.
So this is only about an own form of ourselfs, displaying it within our own application.
Use:
TopLevel = true;
This will do exactly what you want; be topmost as long as the main form is shown and hide if the mainform is hidden by another window.
You can set the owner of your splash form to your main form explicitly without using .Show(owner).
splashForm.Owner=mainForm;
splashManager.Show(splashForm);
We did not want the TopMost property since it works on windows level and covers other windows too (for example the browser).
In the end I hooked up on the focus event of the window to make sure the window is always on top.
I have a WinForms application that, at some point, will do some calculations that take a couple of seconds. During this time, I disable the controls. Additionally I want to display a popup that kind of 'blocks' the application more visibly.
I tried placing a Panel on top of the Form in order to do so, but there I'm somehow not able to add any text to it. I.e. the Labels and ImageBoxes I put there are somehow not displayed or behind the Panel.
Any suggestions how I could achieve this in a quick and easy way? .. I mean, without redesigning the whole Form.
Your problem with the things not showing up in your additional panel is that everything is happening in the same thread, but your calculations are blocking everything from appearing because they are hogging up the thread. You should look into using a backgroundWorker, which is one of the tools in WinForms. You should throw the function call that performs the calculations into the DoWork method of the backgroundWorker, then the form itself can continue to function during the calculations.
See http://msdn.microsoft.com/en-us/library/cc221403%28v=vs.95%29.aspx for examples
Create a Dialog Box (windows form) to popup during the processing, then you can have the Dialog Box close once your processing is completed.
By using a Dialog Box not a Message Box, you can still have control over closing the window when your processing is done.
You could create a simple UserControl with just a Label and an ImageBox, maybe with public setter for their values. You can add it to your form setting its Visible property to false. Then you can make it visible during your calculations and go back top invisible in the end.