I have inherited an ASP.NET/C# project written way back in .NET 1.0. I started programming in .NET 2.0, so some of the antiquated concepts are foreign. I noticed that 80% of the pages have the following snippet or something similar:
#region Component Designer generated code
//Required by the Web Services Designer
private IContainer components = null;
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
connSQL = new System.Data.SqlClient.SqlConnection();
connSQL.ConnectionString = Inventory.Properties.Settings.Default.connectionString;
}
/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose( bool disposing )
{
if(disposing && components != null)
{
components.Dispose();
}
base.Dispose(disposing);
}
#endregion
Although this area is hit in the page load process, commenting it out has no obvious effects on the web page. I can guess that if the connSQL object is used and not initialized elsewhere, then problems can come up, this just hasn't been the case. So, my question is where does this designer generated code come from? I've never seen in it the code behind. Is this another .net 1.0 thing?
I believe it was ASP.NET 2.0 when partial classes were added. Before then, all the designer code had to be included in the code behind. Now, some of that code is separated in a partial class so it doesn't clutter up your code.
I don't know how you created your new pages, but as long as the new init code is working, I wouldn't think you need to hang on to this code.
Related
The team and I are looking at Orchard to use as our CMS. We have a fairly large ASP.NET 4.0 WebForms app and we can only migrate the bits one piece at a time. With that in mind, we will still serve our aspx pages and slowly convert them into the CMS as time allows.
I've noticed on the docs # orchardproject.net/docs, link here, about how one does authorization inside a module. So all that has to be done is include IOrchardService in the constructor of a controller and it'll get injected at runtime.
public AdminController(IMyService myService, IOrchardServices orchardServices) {
_myService = myService;
Services = orchardServices;
}
Because the conversion process will be slow, ¿can I provide a constructor with the IOrchardServices on a System.Web.UI.Page subclass?
// something like this
public partial class Test : System.Web.UI.Page
{
IOrchardServices _service;
public Test(IOrchardServices orchardServices)
{
_service = orchardServices;
}
}
This does not work, throws an exception expecting a default constructor. If I place the default constructor, the page loads correctly but IOrchardServices is not injected. ¿Is this even possible?
I am using VS2008 and have a solution file which contains 1 Website and 1 Class Library Project.
The Class Library is a Custom Control which derives from Label. The Website contains a reference to the control - it builds successfully and the compiled .dll gets added to the Website's /bin folder. I can then use it in any of the website's .aspx pages without error.
What I cannot do, however, is reference any of the Website's data access methods that are in static classes in /App_Code from within the custom control.
I don't want to repeat the website data access logic all over again within the custom control when I know it will already exist in the website - I just want to be able to call a method from a class in /App_Code . If I try and reference anything in /App_Code from within the Class Library, it fails to build and says it can't find the Namespace or that it doesn't exist in the current context.
How can I achieve this so that the Custom Control builds as a standalone control, but can make use of classes in the website it gets used in? Delegates, possibly? Was hoping it might be more straightforward than that.
EDIT: I should add that the reason the control is in a separate Class Library is so that I can include JavaScript as an embedded resource within the Control. So when it's used in a .aspx page, it adds a WebResource.axd? style link to the page instead of a load of plaintext JavaScript in the <head> section.
EDIT 2:
In the website App_Code folder, I have a static class that handles data access (snippet):
[DataObject]
public static class DBAccess
{
[DataObjectMethod(DataObjectMethodType.Select)]
public static DataTable GetSomeData(Int32 SomeParam, DateTime OtherParam)
{
SqlConnection cn = SqlLibrary.GetConnection(DBConnectionString);
DataTable _dt;
SqlLibrary.SProcFill(out _dt, cn, "usp_SomeData_Select", SomeParam, OtherParam);
return _dt;
}
}
In the Class Library's custom control (which I want to build independently of the website's existence, yet be capable of calling its methods when used as a control in an .aspx page):
namespace MyCustomControls
{
public class StatusControl : Label
{
private Int32 _someProperty = -1;
private DateTime _otherProperty = DateTime.Now;
public StatusControl()
{
//some constructor logic
}
public void FetchData()
{
//what I'd **like** to do here is:
DBAccess.GetSomeData(_someProperty, _otherProperty);
//...but DBAccess isn't "visible" to this control at build time
}
}
}
I am working on a Silverlight application using V3 SP1 of MVVM Light Toolkit.
My application is fully French/English. All UI elements (buttons, labels, etc.) and all the data (models). I need dynamic language switching and this is fully implemented and works with anything coming from a resource file. What I am struggling with is the ViewModels.
The Models have language specific prperties (DescriptionEn, DescriptionFr) and an additional property call LocalizedDescription which uses the current culture to return call the language specific property.
When the language changes (via a button click) I raise and broadcast (via the Messenger) a property changed event.
In each of my ViewModels, I register to receive the property changed message for the language swap.
I want to notify all the properties of the ViewModel that something has changed.
From: http://msdn.microsoft.com/en-us/library/system.componentmodel.inotifypropertychanged.propertychanged.aspx
The PropertyChanged event can indicate all properties on the object have changed by using either null or String.Empty as the property name in the PropertyChangedEventArgs.
However, since the toolkit abstracts the raising of the changed event with RaisePropertyChanged(...) I cannot get this to work. I have also examined the source of the tookit and discovered that RaisePropertyChanged calls VerifyPropertyName(..) which in turn returns an error is the property does not belong to the ViewModel. I also noticed that the VerifyPropertyName method is attributed with Conditional("DEBUG"), but even if I choose the Release configuration, the ArgumentException("Property not found") is still raised.
Does anyone know of a way to get this to work using the toolkit aside from manually calling RaisePropertyChanged for every property of the ViewModel?
Follow-up:
Based on the comment from Simon, I attempted to create my own class that extends ViewModelBase. I looked at the source on CodePlex and decided to create a single method called RaiseAllPropertyChanged(). It would simply be a copy of the RaisePropertyChanged(string propertyName) but without the parameter and without the call to VerifyPropertyName(...). I cannot get it to work. Here is what I have.
public class ViewModelBaseExtended : ViewModelBase
{
protected void RaiseAllPropertyChanged()
{
var handler = this.PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(String.Empty));
}
}
}
But I get a compiler error: The event 'GalaSoft.MvvmLight.ViewModelBase.PropertyChanged' can only appear on the left hand side of += or -=. This is a copy of the code that is used in the ViewModelBase.
Can someone offer some advice as to how to get this to work?
Solution:
I copied all the code from ViewModelBase into a new class. I then added the method RaisePropertyChanged() mentioned above which instantiates the PropertyChangedEventArgs class with String.Empty. This is now the new subclass for my ViewModels.
Thanks again to Simon for leading the way!
In case you're reading this in 2016, you can use ObservableObject and notify that all of the properties have changed by doing:
RaisePropertyChanged(string.Empty);
Unfortunately this is not possible with the current code-base of MVVMLight
In the short term your have 2 options:
User your own custom base class. And by custom base class I mean "Do not inherit from the MVVMLight class".
Download and compile MVVMLight in Release mode. This will force the "VerifyPropertyName" method to be excluded. Of course then you don't get the value of property name checks.
I am sure Laurent Bugnion will have this fixed soon.
A lighter solution to this problem would have been to override RaisePropertyChanged(string propertyName) in your class :
protected override void RaisePropertyChanged(string propertyName)
{
if (propertyName != null)
{
base.RaisePropertyChanged(propertyName);
}
else
{
var handler = PropertyChangedHandler;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(null));
}
}
}
I'm a first-time user of the AOP features of Unity 2.0 and would like some advice. My goal is to be able to log method calls in an ASPX page, like so:
public partial class Page2 : Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
[Log]
private void Testing()
{
}
}
Here is the code for the LogAttribute:
public class LogAttribute : HandlerAttribute
{
public override ICallHandler CreateHandler(IUnityContainer container)
{
return new LogHandler(Order);
}
}
Now the LogHandler:
public class LogHandler : ICallHandler
{
public LogHandler(int order)
{
Order = order;
}
public IMethodReturn Invoke(IMethodInvocation input, GetNextHandlerDelegate getNext)
{
string className = input.MethodBase.DeclaringType.Name;
string methodName = input.MethodBase.Name;
string preMethodMessage = string.Format("{0}.{1}", className, methodName);
System.Diagnostics.Debug.WriteLine(preMethodMessage);
return getNext()(input, getNext);
}
public int Order { get; set; }
}
The problem I have is how to use the [Log] attribute. I've seen plenty of example of how to configure the interception settings, for example:
container.AddNewExtension<Interception>();
container.Configure<Interception>().SetDefaultInterceptorFor<ILogger>(new InterfaceInterceptor());
But this implies that I have an interface to intercept, which I don't. I have the ASPX page which uses the [Log] attribute.
so how can I configure Unity to make use of the [Log] attribute? I've done this before using PostSharp and would like to be able to use Unity to do the same.
Cheers.
Jas.
You're unfortunately not going to get this to work in an ASP.NET page with Unity interception.
Unity interception uses a runtime interception model. Depending on the interceptor you choose, you'll either get a subclass with virtual method overrides to call the call handlers (VirtualMethodInterceptor) or a separate proxy object (Interface or TransparentProxyInterceptor) which execute the call handlers and then forward to the real object.
Here's the issue - ASP.NET controls creation and calls to your page, and there's no easy way to hook into them. Without controlling the creation of the page object, you can't use the VirtualMethodInterceptor, because that requires that you instantiate a subclass. And you can't use the proxy version either, because you need ASP.NET to make calls through the proxy.
PostSharp gets around this because it's actually rewriting your IL at compile time.
Assuming you could hook into the creation of the page object, you'd have to use the VirtualMethodInterceptor here. It's a private method, so you want logging on "self" calls (calls from one method of the object into another method on the same object). The proxy-based interceptors can't see those, since the proxy is a separate instance.
I expect there is a hook somewhere to customize how ASP.NET creates object - BuildManager maybe? But I don't know enough about the details, and I expect it'll require some pretty serious hacking to get work.
So, how do you get around this? My recommendation (actually, I'd recommend this anyway) is to use the Model-View-Presenter pattern for your ASP.NET pages. Make the page object itself dumb. All it does is forward calls to a separate object, the Presenter. The Presenter is where your real logic is, and is independent of the details of ASP.NET. You get a huge gain in testability, and you can intercept calls on the presenter without all the difficulty that ASP.NET gives you.
Since there is no ErrorProvider class in .NETCF, how can I implement similar functionality (not necessarily exactly like ErrorProvider)?
I am using all the regular databinding constructs to bind controls to a datatable, using the DataRow.RowError property and DataRow.SetColumnError method, but I can't find events on any of DataTable, BindingManagerBase, etc. that I can hook into to receive any sort of notification.
Am I stuck calling a method to manually iterate through all the controls on my form and change some look/feel of the bound control?
Thanks,
MrB
The ErrorProvider class seems pretty basic - actually, a little too basic. If you have Red Gate Reflector, I would recommend disassembling the class and looking at it. Otherwise, create a Dictionary<Control, String>.
Here is a quick idea on creating your own provider:
Dictionary<Control, String> ErrorSet = new Dictionary<Control, String>();
public void SetError(Control control, String message)
{
// code for adding error information
ErrorSet.Add(control, message);
}
public String GetError(Control control)
{
// code for retrieving error information
return ErrorSet[control];
}
public String Clear()
{
// code for clearing all errors
}
I don't have R-G reflector here or I would provide more sample methods. But this ought to provide some sort of sample to work from.