Social Icons

twitter google plus linkedin rss feed

Pages

22.11.10

Code Snippets in C# and Why my TwoWay Bindings are not working?

Well, regarding to the problem with the TwoWay binding, today I’ve learnt that they don’t work magically; each property should implement the Property Change Notification, the INotifyPropertyChanged. It’s not that complex, It takes a little more time to declare the property this way (by the way, you have it perfectly explained here) and this leads us to the Code Snippets thing.

Creating code snippets is one of those things I’ve left to learn later a lot of times… until today that I had to create an object with more than thirty properties launching the PropertyChanged event and I couldn’t delay it further.
To increase my productivity I have wasted a little of time and I have created a code snippet for the properties implementing the INotifyPropertyChanged. I’ve called it propNot I’m this creative, I can’t help it
To do so, in Visual Studio, I went to Tools and from there to Code Snippets Manager. There I chose C# and then I copied the address of the My Code Snippets folder.

I created a .snippet file on that folder with this content
<CodeSnippets  xmlns="http://schemas.microsoft.com/VisualStudio/2005/CodeSnippet">
 <CodeSnippet Format="1.0.0">
  <Header>
   <Title>propNot</Title>
   <Shortcut>propNot</Shortcut>
   <Description>Code snippet for properties with NotifyPropertyChanged</Description>
   <Author>Chan</Author>
   <SnippetTypes>
    <SnippetType>Expansion</SnippetType>
    <SnippetType>SurroundsWith</SnippetType>
   </SnippetTypes>
  </Header>
  <Snippet>
   <Declarations>
    <Literal>
     <ID>privName</ID>
     <Default>privName</Default>
     <ToolTip>Private name of the property</ToolTip>
    </Literal>
    <Literal>
     <ID>pubName</ID>
     <Default>pubName</Default>
     <ToolTip>Public name of the property</ToolTip>
    </Literal>
    <Literal>
     <ID>type</ID>
     <Default>string</Default>
     <ToolTip>Type of the property</ToolTip>
    </Literal>
   </Declarations>
   <Code Language="csharp"><![CDATA[private $type$ $privName$;
        
    public $type$ $pubName$
    {
     get { return $privName$; }

     set
     {
      $privName$ = value;
      // Call NotifyPropertyChanged when the property is updated
      NotifyPropertyChanged("$pubName$");
     }
    }]]>
   </Code>
  </Snippet>
 </CodeSnippet>
</CodeSnippets>
It’s tested and working, both the TwoWay binding and the Code Snippet.

Now that I know how to do them I think I’ll do them really usually. --EDIT-- I lied, I don't do them that usually because I am VERY lazy, but I do use this other snippet a lot:
<CodeSnippets  xmlns="http://schemas.microsoft.com/VisualStudio/2005/CodeSnippet">
 <CodeSnippet Format="1.0.0">
  <Header>
   <Title>INotify region with the necessary methods to implement the interface</Title>
   <Shortcut>inotifyregion</Shortcut>
   <Description>Creates region with the necessary methods to implement the interface INotifyPropertyChanged</Description>
   <Author>Jose Sanchez</Author>
   <SnippetTypes>
    <SnippetType>Expansion</SnippetType>
    <SnippetType>SurroundsWith</SnippetType>
   </SnippetTypes>
  </Header>
  <Snippet>
   <Declarations />
   <Code Language="csharp"><![CDATA[#region INotifyMethods
        // Declare the event
        public event PropertyChangedEventHandler PropertyChanged;

        // Create the OnPropertyChanged method to raise the event
        protected void NotifyPropertyChanged(string name)
        {
            PropertyChangedEventHandler handler = PropertyChanged;
            if (handler != null)
            {
                handler(this, new PropertyChangedEventArgs(name));
            }
        }
        #endregion]]>
   </Code>
  </Snippet>
 </CodeSnippet>
</CodeSnippets>