Paul Sheriff's Blog for the Real World - All Comments

re: Using Xml Files on Windows Phone

psheriff — Thu, 09 Feb 2012 20:53:56 GMT

Imran,

Yes, using the xElem variable you can call the Save() method. You simply need to save the data into Isolated Storage on the phone.

Paul

re: Using Xml Files on Windows Phone

Imran — Thu, 09 Feb 2012 19:42:03 GMT

You show how to read. Any way to write

re: Using a WPF ListView as a DataGrid

hemantnaik — Wed, 08 Feb 2012 13:07:26 GMT

Nice and Informative, Gr8 Work

re: Wrapping up Configuration Manager

eidand — Tue, 07 Feb 2012 16:10:39 GMT

Yes I can see your point Paul.

I work with AppSettings quite a bit and never needed anything but a generic library class for it hence why I code it in this manner.

The reason I do like extension methods is because they keep the code extremely clean and readable which is very important to me. I can look at that 1 line method and I'll never have to ask myself what it does because it's pretty clear.

In the end I guess it's all down to personal preference. It's good to have alternatives and and it's even better to see how others do exactly what you are doing, just in a very different way :).

re: Wrapping up Configuration Manager

psheriff — Tue, 07 Feb 2012 15:43:08 GMT

Andrei,

Thanks for posting your code. Yes, you can use static methods. However, I often find that when I use static I end up needing an instance of my properties at some point. I will then often use a singleton pattern where I add code like the following:

private static AppConfig _Instance = null;

public static AppConfig Instance

{

get

{

if (_Instance == null)

_Instance = new AppConfig();

return _Instance;

}

set

{

_Instance = value;

}

By doing this, I can use 1 line of code:

string path = AppConfig.Instance.GetSetting("XmlPath", "");

Personally I am not a big fan of extension methods. I find programmer's do not always know they are there and I don't trust Microsoft to keep supporting them. This was one of the main points of my blog, I am trying to wrap up Microsoft's stuff so "when" they change things, I can modify my stuff in one place. :)

Paul

re: Wrapping up Configuration Manager

Andrei — Tue, 07 Feb 2012 09:42:02 GMT

that's a lot of code for something which is inherently very simple.

I use a static function for this type of work which simply checks for null and returns an empty string if the value is missing from appsettings.

If I need the result returned as a specific type then I have a few extension methods which do what I need in one simple call. This is really a library function, does not require an instance of a class and can be called with 1 line of code.

More than that, the extension methods can be applied to anything of a certain type, so the code is reusable and used in other parts of the system not by a wrapper class.

Example :

public static class GenericFunctionality

{

public static string RetrieveAppSetting(string AppSettingName)

{

string result = string.Empty;

if (ConfigurationManager.AppSettings[AppSettingName] != null)

result = ConfigurationManager.AppSettings[AppSettingName].ToString();

return result;

}

Extension :

public static int ToInt(this string source)

{

int result = 0;

int.TryParse(source, out result);

return result;

}

Usage : int result = GenericFunctionality.RetrieveAppSetting("something").ToInt();

a bit more code can be added to ensure against passing nulls to the function I suppose but, I feel this implementation is a bit more useful

re: Creating a Base Window Class in WPF

psheriff — Mon, 06 Feb 2012 16:05:50 GMT

Clint,

No, this still works. I use this technique all the time. I am using Visual Studio 2010.

The one thing I notice is that your x:Class="myEmailer...", but your base class is in another namespace. Is your ClientWindow in another DLL? If so, then you need the Assembly reference in your xmlns:src="...".

Paul

re: Creating a Base Window Class in WPF

Clint — Sat, 04 Feb 2012 17:29:46 GMT

Has this changed in the last few months or recent WPF release/C# 4 release?

I get an error of "Only a root tag can specify attribute 'x:Class'. Line 2 Postition 5" Which is this:

<src:myClient.ClientWindow

x:Class="myEmailer.EmailMessageWindow"

xmlns="schemas.microsoft.com/.../presentation"

xmlns:x="schemas.microsoft.com/.../xaml"

xmlns:src="clr-namespace:myClient"

The theory being I'm working on a client/server package. There will be several different types of client applications for different purposes all talking to the same server. So I want each client to inherit from a client base where all the communication protocol stuff is located.

So I made a base ClientWindow, then want to inherit from that for the EmailClient, UserClient, PosClient and so on.

re: Windows Phone List Box with Images

Jayamohan — Fri, 03 Feb 2012 02:05:32 GMT

This was really useful. I had used your source snippet in my application. I was planning to use a lot of source lines to implement the same. But your simple way of using the the XAML files to populate the values helped me a lot.

re: Filtering CollectionView Data in Silverlight 4

ricardo — Sat, 28 Jan 2012 04:58:43 GMT

You solve all my filtering and grouping problems which I spent most of my day looking for a solution, PagedCollectionView is the way to go...

My filter is based on categories selected from a dropdown, all the same the .Filter = Query is what I needed...

Thanks a million!!!