Updates to Silverlight Code Browser

A couple of bits of news. I did a number of updates to the HackingSilverlightCodeBrowser here:

http://www.hackingsilverlight.net/HackingSilverlightCodeBrowser.html

including things like MEF and IsolatedStorage. As to the community edition of the book, I'm still trying to get some contributors to finish. I've been slammed with 60 hour weeks so chapter 2 and 4 and appendix a still need edits. maybe a weeks worth of work pending time which tends to be limited in my life. :)

Isolated Storage Made Easy

In its most simple form Isolated Storage allows you to save name value pairs and retrieve them at some other time the next time your app runs. Granted we could get into XML and text files etc but I'm going to stick with just name value pairs. Lets take a look at this line:

private void PresistKeyValue(string _Key, string _Value)
{
StreamWriter MyWriter = new StreamWriter(new IsolatedStorageFileStream(_Key, FileMode.Create, IsolatedStorageFile.GetUserStoreForApplication()));
MyWriter.Write(_Value);
MyWriter.Close();
}

Nice and simple. using this block we can use a line like this:

PresistKeyValue("foobarkey", "blah blah blah");

this like saves a key falue of 'foobarkey' with the 'blah blah blah' as the 'value'

Now then to get the data you need a block like this:
private string ReturnKey(string _Key)
{
string Output = String.Empty;

StreamReader sr = new StreamReader(new IsolatedStorageFileStream(_Key, FileMode.Open, IsolatedStorageFile.GetUserStoreForApplication()));

string ALine = String.Empty;
while ((ALine = sr.ReadLine()) != null)
{
Output += ALine;
}

return Output;
}

Yes a little simple but you should be able to lift both of these functions directly and use the code as such like this to regtrieve values:

string SomeValue = ReturnKey("foobarkey");

nice and simple.

Dependency Properties Made Easy

ok so I found that for some reason I thought I did a post on this before and I couldn't find it. So I thought I would make a new post as simple as possible. Here is a simple dp:


public readonly DependencyProperty ResistanceProperty = DependencyProperty.Register("Resistance", typeof(double), typeof(AnimatingPanelBase), null);
public double Resistance
{
get
{
return (double)GetValue(ResistanceProperty);
}
set
{
SetValue(ResistanceProperty, value);
}
}

Nice and simple right? why bother you ask, well the biggest issue is that if you want to animate properties of a custom control of some kind using data binding and what that change to filter into the UI of some control. Otherwise I try to avoid DP's as much as possible. So if you need todo some mucking around in your control after the DP value has changed then do this:

public static readonly DependencyProperty MinimumProperty = DependencyProperty.Register("Minimum", typeof(double), typeof(Dial), new PropertyMetadata(new PropertyChangedCallback(OnMinimumChanged)));

public double Minimum
{
get
{
return (double)GetValue(MinimumProperty);
}
set
{
SetValue(MinimumProperty, value);
}
}
private static void OnMinimumChanged(DependencyObject DpObj, DependencyPropertyChangedEventArgs e)
{
// some code :
}

You'll note that this has a changed handler but otherwise is like the first version. and that is pretty much it. :)