how can i access a public function in an .ascx file using C#?
Thanks
If the function is not static you will need to first obtain an instance of the class containing the function and then invoke the function on this instance. For example:
<%
// obtain an instance of the type containing the function
Foo instance = new Foo();
// invoke the function on this instance
string result = instance.Bar();
%>
Obviously it would be better to do this in the code behind file instead of polluting your markup.
Like other public functions in .NET Framework - via object reference. But sometimes Visual Studio doesn't automatically see your User Control's public members. Try to rebuild your user control and the site if IntelliSense window doesn't show it to you.
Where are you calling the function from? The containing page? Masterpage? Parent control? The control itself? Regardless, you'll need to somehow obtain a reference to the control instance (unless the method is static) in order to invoke this method. And the type of your reference must match that of the class that defines the method.
Edit:
MyControl myControl = (MyControl)Page.FindControl("Id_Of_The_Control");
if (myControl != null)
{
myControl.TheMethod();
}
if you don't want to add your ascx control into a placeholder programmatically, just implement IAttributeAccessor and IUserControlDesignerAccessor interfaces to your user control class like;
public partial class yourascxclassname: System.Web.UI.UserControl, IAttributeAccessor, IUserControlDesignerAccessor
you can access only public members of your ascx control.
Related
if i have
public partial class MyLittlePage: System.Web.UI.Page
{...
and i have overriden for example the OnLoad...
my question : where in the code(reflector) does the compiler creates this :
System.Web.UI.Page= new MyLittlePage(); ??
i want to see all the chain of the polymorphic affect..
(or in other words : i'm overloading OnLoad for what virtual function ? )
i know the virtual function is on the Control Page
but i wasn't able to see the Polymorphic creation pattern of :
Class1 x = new Class2();
In the depths of ASP.NET 4...
HttpApplication uses the nested MaterializeHandlerExecutionStep class to populate HttpContext.Handler from an IHttpHandlerFactory.
Through a layer of caching, requests for Page (and all types implementing IHttpHandler) use an instance of System.Web.Configuration.HandlerFactoryWrapper.
HandlerFactoryWrapper.GetHandler() in turn calls HttpRuntime.CreateNonPublicInstance(), which uses Activator.CreateInstance() to instantiate the class.
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'm building a site on the new Razor engine that comes with MVC 3 (and loving the new syntax!). However, I am at a loss about using public properties / constants with it. I know that with WebForms we could add a public property in code behind:
public string ImageFolder { get; set; }
I would like to define important variables in one global place that my views can access, starting with paths to CSS files and images:
#{
Layout = "~/Views/Shared/_Layout.cshtml";
var ContentFolder = "~/Content";
var CssFolder = ContentFolder + "/Stylesheets";
var ImageFolder = ContentFolder + "/Images";
}
I have tried putting the above code block in _Layout, as well as inside _ViewStart. However, accessing them from child views fails miserably. I thought of defining a public property in the above code block but it doesn't compile.
Solutions?
As far as I have seen, noone uses code behind with Razor.
I guess I should be able to inherit from the default view and define my properties there (as described on Stack).
But I'm strongly hoping that there should be an easier way to do something so simple?
I decided to follow yet another path, and extended UrlHelper to provide paths to all three folders I think I might need:
public static class ExtensionMethods
{
private const string ImagesFolder = "~/Images";
private const string StylesheetsFolder = "~/Stylesheets";
private const string ScriptsFolder = "~/Scripts";
public static string Images(this UrlHelper url)
{
return url.Content(ImagesFolder);
}
public static string Stylesheets(this UrlHelper url)
{
return url.Content(StylesheetsFolder);
}
public static string Scripts(this UrlHelper url)
{
return url.Content(ScriptsFolder);
}
}
All good to go... almost :-) I'm now wondering if there's a place where I would be able to define the using MyNamespace.Helper statement would go in order for these extension methods to be available application-wide. In the old days we would add an entry in web.config:
<system.web>
<pages>
<namespaces>
<add namespace="MyNamespace.Helper"/>
</namespaces>
</pages>
</system.web>
This doesn't seem to work with Razor :-( I tried adding a using statement in _ViewStart.cshtml but no luck either - the only way for my extension methods to be visible is to add a using statement on a particular page, which again isn't ideal.
Any suggestions? Have any of you seen an explanation of Razor's order of page parsing & delivery?
Your can create a folder "App_Code" and create a file "GlobalVal.cshtml".
bellow is a sample code in the file:
#functions{
public static readonly string __siteHome = "http://www.example.com";
public static readonly string __siteResource = "http://resource.example.com";
}
and bellow is a sample using it:
#GlobalVal.__siteHome
Use the PageData property:
#{
Layout = "~/Views/Shared/_Layout.cshtml";
PageData.Add("ContentFolder", "~/Content");
}
and inside _Layout.cshtml:
<%=PageData["ContentFolder"]%>
In _layout view
#{
App.AnyName = "abc";
}
In Inherit view
#{
var anyVariable = App.AnyName;
}
Just place the constants in a public module inside your app_code folder, or if you don't want to do that just create a clasas in app_code and use the using (imports) keyword to import the namespace (class name) in each view and you can use it that way.
Alternatively, if it makes sense to do so, just add them in your view model - remember, it might not make sense to add those vars to your model, but it can make sense to add them to your view model! This is what the view model is for, and this view model can grab the constant values from a public module or class or you can even set it in your actual view model itself, this way you will only define the values in one place and you don't need to use any namespace imports into each view :)
Let me know how it goes and if there is anything else I can do to help you out.
In vb.net but same as csharp and its easy to understand since it's vb.
Public class YourModel
// this is where you have the normal model you have... No big deal
End Class
...
// now you make the view model urself
...
Public class MyViewModel
Public MyNormalModel as YourModel
//notice we r declaring ur normal model as a variable, u can use a property instead
Public MyPathConstant1 as string = "abc"
Public MyPathConstant2 as string = "abc"
Public MyPathConstant3 as string = "abc"
End Class
Now, you gotta set the value of MyNormalModel to ur current model instance, although you can do that in ur controller, it's best practice to create a method inside the MyViewModel class that takes a copy of ur current model as argument and does the setting of MyNormalModel to the current model we just passed in the argument.
You can still make that call in your controller, but on another note, what people prefer to do is, instead of passing the whole normal model as a property, the just take the bits and pieces they need from the normal model and place them into the view (ie: you might just need half the properties in the normal model to be in the view model). This is because, remember, the view model will be passed to the view and they don't wanna pass things they wont use :). But this means you are going to need to set each of those properties one by one most likely (unless those exact ones are encapsulated in a sub class which usually doesn't happen by chance lol).
I kept it in one so you can just copy the normal model over in one shot for simplicity.
Now when you pass the view model to your view (MyViewModel) you will be able to use and access the normal model through the object notation and it's properties, eg... Model.MyNormalModel.Property1. Etc and do whatever you want with it in the view... Also, you can access the rest of your view model (the const values that we set) like this... Model.MyPathConstant1 and Model.MyPathConstant2 etc... So you have access to practically everything you want, ur normal model and whatever else you added later on all through what is now called your view model.
Please excuse typos -writing from and ipad lol. Let me know if this is making more sense.
You could use the built-in property of UrlHelper Content:
#Url.Content("~/Content/Stylsheets")
#Url.Content("~/Content/Images")
How to declare a global variable or a public sub in a web application that all aspx pages can have access to?
use a static variable in one of your code files.
"Global" variables can be kept in Cache using Cache.Add, or Application state using Application.Add.
"Globally-available" methods are generally an antipattern and should be avoided. If you need a utility function you can add a static method to a class, but beware the Ball of Mud antipattern.
1.You can use session variables which will be available to all pages in the scope of current session.
C#
Session("name")=value;
2.You can use application variables which will be available to entire application code untill application ends.
Application("name") = value;
Global.asax inherits from YourWebSiteApplicationClass...
public class YourWebSiteApplicationClass : HttpApplication
{
public string GlobalVariable;
public YourWebSiteApplicationClass()
{
GlobalVariable = "GLOBAL_VARIABLE";
}
}
...and in any .aspx or .cs(.vb) file...
<% = ((YourWebSiteApplicationClass)this.ApplicationInstance).GlobalVariable %>
Return "GLOBAL_VARIABLE".
Create a PageBase class and have your pages inherit from it.
I want to unit test my rendering engine for an ASP.NET app. I have some custom controls created in that app. Most of those control rely on having CreateChildControls() method called by the ASP.Net engine wheather during initial call or a postback.
When running a test CreateChildControls() does not get called and the control is in an "invalid" state.
As a workaround to get the tests going I explicitly call some other public method that calls EnsureChildControls() in it. This in effect causes CreateChildControls() to be executed and the control being initialized properly (just as it would normally when hosted on web server).
I would like to get rid of that extra method call and the control to still be in a proper state for testing.
Are there any elegant solutions to this problem?
You could alternatively use reflection to call CreateChildControls directly, thereby escaping the need to use the public method to invoke it. That would be easy enough:
var methodInfo = control.GetType().GetMethod("CreateChildControls", BindingFlags.Instance | BindingFlags.NonPublic);
methodInfo.Invoke(control, new object[] { });
You could embed this code somewhere so that you only need to do this once and reuse it.
EDIT: You could have your test inherit from your control too, so you can invoke some of these methods directly. But you have to instantiate your control by instantiating the test and not the control, as in:
public class CtlTest : Ctl
{
[Test]
public void A()
{
var ctl = new CtlTest();
ctl.RecreateChildControls(); //protected, but can be accessed because of inheritance
}
}
HTH.