One of the challenges in building a UI application is correctly using the UI thread. This is a shared resource, and so any misuse has the potential to have global application effect. The most common form of misuse is using the UI thread for a long...

Launching a child window inside MMC 3.0 from managed code isn’t easy. Different APIs are required for different circumstances. I don’t know exactly why this is, but I assume it has something to do with all the tricks MMC does to give each managed...

Actually the title of this article should be entitled “How to use WeakEventManager with ICommand implementations”, but the memory leak title is more exciting (and true) Overview Some WPF controls, such as Buttons, are command sources . A command...

When my team first starting hitting “memory leaks” due to event handlers we investigated a variety of solutions. There are many examples on the web for implementing some kind of weak listener – but interestingly almost all of them have some flaw. In the...

One cool thing about DependencyProperties is the ability to have AttachedDependencyProperties (or Attached Property for short). Regular properties are defined on a type and exist for instances of that type and sub-classes. An Attached Property is defined...

On a WinForms project in the past we were working on scalability and performance. One of the things we discovered was that individually invoking items to the UI thread was a bottleneck. The theory is that the each time one does a BeginInvoke it adds...

The Issue Recently a friend asked a question about ObservableCollection. The question was how to do an “AddRange” method on it. The obvious answer is, of course, just write a method which iterates over the input collection and calls Add for each...

There have been several great blogs and articles about the Model-View-ViewModel pattern lately. I thought I would share my own example and thoughts on it – specifically on using this pattern to develop reusable controls. Rather than re-explain what...

Recently I was asked to modify one of my controls so the user of the control could get the proper placement of thier context menus. My intial response was for them to use the placement properties on the ContextMenu/ContextMenuService to achieve the right...

I've been working on a problem of having a "popup" control in my project. For various reasons the Popup class isn't working for this scenario, because the scenario is outside the designed scope of Popup. So I've been looking at the AdornerLayer as...

In my project we always deal with live data - that is data from the Data Model may change at any minute due to reasons like user interaction or an asynchronous change in what system the UI is modeling. For the most part we want the UI to update automatically...