referring c# instance of object variable name with a string

referring c# instance of object variable name with a string

In Windows 7 phone (Silverlight platform), when a ListBox is created, the name of that ListBox is instatiated and assigned to a variable of the same name:

<ListBox Name="abcFeed" ... 

and used as:

abcFeed.ItemsSource = feed.Items; 

In my app I have many feeds and want to assign them to their respective ListBoxes. I have the names of the list boxes in a dictionary of strings.

this.feeds["abcFeed"] = "http://feed.abc.com/...."; this.feeds["nbcFeed"] = "http://feed.nbc.com/...."; 

But other than using a switch to assign the feeds to the ListBoxes I was wanting to take the ListBox string names from my dictionary and in a loop dynamically call the instances.

For example instead of doing:

feedName = "nbcFeed"; // Bind the list of SyndicationItems to our ListBox. switch (feedName) {   case "abcFeed":     abcFeed.ItemsSource = feed.Items;     break;   case "nbcFeed":     nbcFeed.ItemsSource = feed.Items;     break; } 

I would like to somehow take the dictionary keys and call the instantiated variablename like:

feedName = "nbcFeed"; // nbcFeed.ItemsSource = feed.Items; ((ListBox) feedName).ItemsSource = feed.Items; 

I've looked into Reflection, Assembly, and Activator.CreateInstance() (I already hve the instance though) but Im not getting a clear understanding if this is possible.

Can this be done or am I stuck with the switch?

I also tried:

this.GetType().GetProperty(feedName).ItemsSource = feed.Items; 

but I get an error:

Cannot convert lambda expression to type 'System.Delegate' because it is not a delegate type

Answers & Comments...

Answer: 1

Yes, Reflection is what you need to do this. But this:

this.GetType().GetProperty(feedName).ItemsSource = feed.Items;

doesn't work because Type.GetProperty() method returns a PropertyInfo (as Type.GetMethod() returns MethodInfo and so on...) so you should use PropertyInfo.GetValue() or PropertyInfo.SetValue() method if you want to work on the property value.

In your case this could work:

var myProperty = (ItemsControl)GetType().GetProperty(feedName).GetValue(this, null);  myProperty.ItemsSource = feed.Items; 

by : Fuexhttp://stackoverflow.com/users/1141063

Answer: 2

Unfortunately, you cannot access fields defined in XAML using reflection. Security restrictions in Silverlight prevent access to NonPublic fields (such as those generated for your XAML elements).

Using FindName should work fine.

ListBox abcFeed = LayoutRoot.FindName("abcFeed") as ListBox; 

by : TriggerPinhttp://stackoverflow.com/users/1549726

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