sorta new with Angular, odds are I can't do it... However,
What I'm trying to do is take a button and use the click event to call the bound objects codebehind method (without use of javascript functions):
i.e.: ng-click="MyClassObject.Method(param)"
Is this possible? and if so, what am I missing? :/
Note the object is bound, and data members are being used elsewhere in the view..
Related
I'm trying to create a function that adds usercontrols to my mainform. I want this function to be available from the usercontrols themselves as well, so I'm making it static.
My problem is that when it's static I can't use this.Controls.Add(ucontrol);, I tried to change it to ActiveForm.Controls.Add(ucontrol); but then ActiveForm is NULL and has no Controls property (throws an exception).
UPDATE #1: I ended up doing something like this inside the usercontrol:
MainForm ref_to_mainform_to_gain_access_to_functions = (MainForm)Parent;
ref_to_mainform_to_gain_access_to_functions.DisplayControl(ucontrol);
maybe it's even better, but I still assume it's possible to have access to the mainform from a static method?
UPDATE #2:
Application.OpenForms["FormName"]
worked from static method.
I still try to find out if that usercontrol entire purpose is serve as a menu with buttons that shows other usercontrols onclick, is it still a 'design-crime' to call a function on mainform (a function that shows usercontrols) from a user control? (like I did in 'update #1')
By adding controls from a user control to its parent you are breaking the separation of concerns principle and you are tightly coupling both controls/forms. As suggested by Hans Passant you should use events. Please refer to:
best practices to call methods in the parent form and access gui elements in parent form in c#
I have a Silverlight control with a method named DoSomething() decorated with the <ScriptableMember()> attribute. I then call this method successfully from JavaScript and proved by a little message box that apprears from the SL side that says "Method Called!".
Point is all that works. The problem I am having is that prior to calling this method I build up an ObservableCollection on the Silverlight control containing 1..n FileInfo objects. This works fine too and builds up as I add files to it. Each time I add a file, a messagebox tells me the count from Silverlight (i.e. "Count = 2").
Now the problem: when I call the method DoSomething() from JS and access that ObservableCollection the count = 0! To see what is going on I placed a message in the Silverlight control's constructor to see if it gets entered upon being called from JS, and indeed it does and appears to recreate the control.
If this is the case it kind of makes sense that my ObservableCollection has a count = 0 because it is not the same control instance where I built up the FileInfo collection.
So how in the world do I preserve the collection, and why would simply calling a method exposed to JS from Silverlight, recreate the control and not allow me to access it's given state? I don't want a new control, I need to manipulate it as-is. Or am I off base and doing something else wrong to cause this beahvior?
Thoughts? Thanks!
It turns out the instance registered was the culprit. The MSDN examples show registering a new instance of the type, but in my case I needed the actual instance of the Page Control itself which solved the problem.
So at the completion of my page's initialization, I could register the current page's instance like below:
HtmlPage.RegisterScriptableObject("SLControl", Me)
This allowed me from JS to access the control in it's current state which included all objects in the ObservableCollection as required. I blogged about this topic with code examples and the article below expands on this situation:
Get A Silverlight Control's Current Instance For Communicating Via The HTML Bridge:
http://allen-conway-dotnet.blogspot.com/2012/03/get-silverlight-controls-current.html
I've extended my domain class on the silverlight client side in a partial class. Specifically, I've added a RelayCommand property that I will be binding a button to. The RelayCommand property needs to be initialized, and so it would seem that the best place to do that would be in the OnCreated partial method.
However I gather that when the object from the server is materialized on the client side its constructor is not called (which seems totally wrong headed to me!) Since it's constructor is not called, it's not calling the OnCreated Method.
Is there a config or a convention for getting this OnCreated partial method to be called as the objects are materialized?
DataContractSerialization does not call the constructor of the objects that it deserializes. This decision was made because with the previous serialization methods in .NET having to always have a default constructor on any object that was going to be serialized was a problem. This is not specific to RIA Services, it was a design decision made when WCF itself was created and there is no configuration to change it.
You can find more information at http://blogs.msdn.com/b/carlosfigueira/archive/2011/09/06/wcf-extensibility-serialization-callbacks.aspx as well as examples of how you can use [OnDeserialized] to replicate the effect of the constructor being called.
However, there is a second issue that may cause you problems. Entities get constructed all the time. For example, any time you call TEntity.GetOriginal a new detached entity is being created and returned from the method. That makes trying to do anything like configuring a RelayCommand a potential performance and stability problem. You are probably better off configuring RelayCommands at the DataService or ViewModel level instead of inside the entity itself.
The partial method OnCreated() is only called when you instantiate an Entity using its default constructor.
If you want to initialize your loaded entities you have to override the OnLoaded method. A boolean is passed to it that specifies if the entity was loaded first time or not.
I am working with the Infragistics XamDatagrid. When an event takes place in the view (new record updated), I would like to call a method in the view model. I can't just listen to the CollectionChanged event of the source in the VM because that event gets triggered once the user begins editing the new row in the grid. The RecordUpdating event gets called when the user finished the edits.
What I am doing now is accessing the DataContext directly and calling the method. The problem is that there is nowhere I can find to attach a Command to the gird that would tigger on the event I am interested, nothing like the Command of a Button.
Generally, what is the best way to call into a VM from a view when there is no Command parameter I can set in the view?
Code-behind glue is fine in most cases, but if you find yourself gluing the same type of thing repeatedly, you can look into Attached Behaviors. Here's one old-school approach the introduces the concepts, but doesn't use the new Behavior class: http://www.codeproject.com/KB/WPF/AttachedBehaviors.aspx
Here is an example using the new Behavior class, including a demonstration of how it integrates with Blend: http://geekswithblogs.net/lbugnion/archive/2009/04/05/using-a-behavior-to-magnify-your-wpf-applications.aspx
I am trying to display a simple text block that shows the value of AvailableFreeSpace from IsolatedStorage.
That is: System.IO.IsolatedStorage.IsolatedStorageFile.GetUserStoreForApplication().AvailableFreeSpace
It needs to dynamically update as the available storage changes.
I know this is probably basic but I can't figure out how to bind to this variable. Any hints?
When you bind a property on a plain old CLR object, like IsolatedStorageFile.AvailableFreeSpace, to a UI property like TextBlock.Text you actually need to do a little extra work to make sure that changes in the CLR property are propagated to the UI. In SL, that means the CLR object (IsolatedStorageFile in this case) needs to implement INotifyPropertyChanged. The implementation is very simple, just add an event to your object called PropertyChanged; then fire that event every time something interesting changes which would be AvailableFreeSpace in your case. Since IsolatedStorageFile doesn't implement INotifyPropertyChanged you won't get updates when the AvailableFreeSpace changes. You'll need to create your own class that implements this interface, then use some mechanism like timer based polling to check IsolatedStorageFile.AvailableFreeSpace on a regular basis and reflect changes in your own AvailableFreeSpace property. Personally I would run all write calls to isolated storage through a custom class that would check the free space after the write operation and report those changes to the class you created with a custom AvailableFreeSpace property, making sure to fire the PropertyChanged event when this happens instead of using a timer to check periodically.