In my winforms app, I have a UserControl that contains a DataGridView. I instantiate and load this UserControl when needed into a panel in my Main Form (frmMain). My problem is figuring out how to resond to or listen for events raised in my UC's DataGridView. For example, I want to handle the CellDoubleClick event of the DataGridView in my Main Form rather than through the UC.
Is this possible? I had thought of updating a property when the cell in the grid is double-clicked, and then let my Main form do whatever when that property changes - therefore I thought of using INotifyPropertyChanged. Im not heavily clued up on how to use it in m scenario however, and would deeply appreciate some help in this regard, or if anyone can suggest an alternate solution.
Much thanx!
Your user control must encapsulate some logic, so if you want to handle event of the DataGridView that is in your control the way you've described, you probably missing something in idea of user controls and encapsulation. Technically here two ways to do this:
Make a public property in your user control of type DataGridView.
Make an event wrapper. You will need to create an event in your user control that is raised when DataGridView CellDoubleClick (or any) is rased and in your calling code you will handle this event wrapper.
The second approach is more logical, cos internal logic of your control is incapsulated and you can provide end-user of you component with more logical and meaningful event then CellDoubleClidk or else.
thank u 4 your reply. Sorry for not responding earlier. I did manage to sort this issue out by creating a public event in my UC:
public event DataGridViewCellEventHandler GridRowDoubleClick {
add { dgvTasks.CellDoubleClick += value; }
remove { dgvTasks.CellDoubleClick -= value; }
}
and in my main form, after I instantiate and load the UC
_ucTask.GridRowDoubleClick += new DataGridViewCellEventHandler(TasksGrid_CellDoubleClick);
with the following attached event:
private void TasksGrid_CellDoubleClick( object sender, DataGridViewCellEventArgs e ) {
// do work here!
}
This does work, although I don't know if any of u experts out there foresee a problem with this approach.
Related
I am working in Dynamics AX7 form development. I have to write code in 'Clicked' method of a button, but there is already some 'Sys Layer' code in 'Clicked' method. I have to apply some conditions on it. But I don't want to do 'over-layering', i have to do it with Extensions, but if I write code in onClicked event, the problem is, my code runs before or after the sys-layer code, but i need to apply some conditions on that sys-layer code.
my question is, can we achieve this logic with extension event handlers ? I have already done it with over-layering, but I need to do it with extensions. So is it possible to do it with extensions ?
Code is added below.
void clicked()
{
super();
// My logic will be written here
if(result == true) //This is my code, based on above logic I applied this check
{
// start of sys layer code
remainSalesPhysical.realValue(0);
remainInventPhysical.realValue(0);
if (formCtrl)
{
formCtrl.cancelLine();
}
element.closeOk();
// end of sys layer code
} //this is my code
else //this is my code
{ //this is my code
error("Some error message"); //this is my code
} //this is my code
}
Yes and no. If it's just a button then the super() doesn't really do anything, so you can do a pre event handler.
If it's a menu item button, where the super() calls a class, then you would do a post event handler to the class and not the button, so that way your logic runs immediately after the super() call.
And in your class, you can do something like formRun = _xppPrePostArgs.getThis() and then if (formRun.name() == formStr(SalesTable)) or any number of things if the class has multiple entry points.
I have searched about it and what i concluded so far is that, we can't do it 100% without overlayering. We have Pre and Post events but these are unable to cater the above mentioned problem, May be in future we will have some more specific way of doing this, but for now we have three options.
Do overlayering as we did in AX 2012 (which is not recommended)
Do it With Delegates (even with delegates we're restricted to do some overlayering, but it is recommended way)
You can also hide that button and replace it with your own button, but it will work only for Form Controls, we can't do it for methods, as you can't avoid calling them.
I solved my problem using delegates.
Here is a Helpful link I found about it and it helped.
https://ievgensaxblog.wordpress.com/2016/05/01/ax-7-how-to-override-form-data-source-field-methods-without-overlaying/
I am a noob to Windows Forms so this is likely a remedial question. I have a child component with a button and a text field. I want to use multiple instances of these in a parent component or form. At runtime, when the user clicks one of the buttons, I want the parent to get the event to decide what to do with the associated text.
Coming from the long lost world of Borland C++ Builder, during design time, I would simply double-click on the buttons and handlers in the parent would be created which I could just elaborate the code. With Windows Forms, the component controls are not clickable (at design time) from the parent and are "frozen". It is not obvious to me how to pass any child button clicks to a parent. I've tried things like changing the button modifier from private to public but that doesn't help. How is this best accomplished.
Note I am using C++ as I am sharing header file definitions with an associated C++ embedded app.
-Bob
UPDATE:
My apologies, I thought I was still in my C# search :(
This is slightly complicated if you actually want to bubble up an event, or very easy if you use methods.
Methods:
In your child container, add a constructor or property that takes in and stores the parent. Then in the button handler, call this.Parent.ButtonClicked(this); and of course in the parent, add a ButtonClicked(ChildType child) method. That should get you there that way.
Custom Event:
To use events, you need to add a few things. Firstly, add a custom EventArgs class as such:
class ChildClickedEventArgs : EventArgs
{
// include a ctor and property to store and retrieve the child instance.
}
Then add a public delegate for it:
public delegate void ChildClickedEventHandler(object sender, ChildClickedEventArgs e);
Then to your child class, add a ButtonClicked event:
public event ChildClickedEventHandler ChildClicked;
And finally, a helper method to raise it:
private OnButtonClicked()
{
if (this.ChildClicked != null)
{
this.ChildClicked(this, new ChildClickedEventArgs(this));
}
}
Then when you add the child class to the parent, add an event handler for each, and you can handle your custom event for your custom control.
Alternatively:
If you can expose the Button in your child class, simply do the above but register it to this.child.Button.Clicked, saving adding the event handler yourself.
Ok, so what I am looking to do is to display some sort of login control (maybe a UserControl with a TextBox and PasswordBox) when the app is started.
In a non-mvvm situation, a way of doing this would be to use the PopUp primitive control, add the usercontrol as a child element and off you go.
In an MVVM situation, i'm a bit confused about how you would achieve a simmilar result.
I have looked into messaging with the DialogMessage and this is fine for displaying a typical MessageBox, but what about a custom usercontrol?
any help would be fantastic! I can't seem to find any demo code of this anywhere.
In a MVVM situation you can use a delegate to let your View open the dialog when the ViewModel requests it.
You define a delegate at the VM:
public Func<LoginResult> ShowLoginDialogDelegate;
In your View you define the function that will be called:
private LoginResult ShowLoginDialog()
{
LoginResult result;
// show a dialog and get the login data
return result;
}
Then you "connect" the delegate and method in the View:
_viewModel = new MyViewModel();
DataContext = _viewModel;
_viewModel.ShowLoginDialogDelegate += ShowLoginDialog;
And now you can use it in your ViewModel e.g. when a command is executed like that:
LoginResult result = ShowLoginDialogDelegate();
An easier answer is to control it's visibility through a View State which with a little manipulation can be made to work through databinding allowing the view model to display the "Logon Page" state when required.
I just recently wrote about this for the Silverlight/XNA series which you can view here.
It would be much simplier if the SL4 DataEventrigger was available but hay ho.
I am using this code to map a database to my Windows Phone 7 application.
In particular when I add a new Card item (in a Phone Page different from the home page) and when I get back to the home page the balance value of my Credit Card list does not update (Which is bound to an observable collection of type Card). I think I have added all the necessary NotifyPropertyChanged.
Am I missing something:
Code: Here
This is kind of a shot in the dark, but I don't see PropertyChanged being set anywhere... if PropertyChanged does not get set, then it will equal null and none of the NotifyPropertyChanged calls will actually call PropertyChanged().
I had a problem once that wouldnt update my URI, just try to actualize when you can, not sure how to go about your particular problem but I had a problem that when I changed teams in my app, the main page wouldnt update the statistics when you returned to it, so I just added a method that retrieves the value once more, I use nested classes with setters and getters so its all handled for me
protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)
{
method();
base.OnNavigatedTo(e);
}
I am developing a Windows Phone7 application in which I have two App bar buttons both when clicked makes Asynchronous calls to Web and Callbacks will be performed upon the Web response.
Now my problem is, if I click on one button and as the Async operation is going on in the background ans meanwhile if I click on another button both callbacks are executing one after the other, which is not good for obvious reasons. Could any one help me on how to handle this???
First I thought to disable other buttons when 1 Async operation is going. But it doesnt give good feel for user. So what will be the best way to handle this problem??
You can use a Flag variable and check its value within the async call complete method. Based on your requirement you can choose to update or not update the view.
I was looking for the same answer.
I have found the solution, If you initialize an object inside a constructor like this, you will get multiple loops when you call a service function:
public partial class MainPage : PhoneApplicationPage
{
MovieServiceClient mov;
public MainPage()
{
mov = new MovieServiceClient(); //Don't do this.
InitializeComponent();
}
}
Avoid that.