static private void SearchListAndRemoveEventHandlers(object pObjectToUnhook)
{
if (_UserPreferenceChangedList == null)
{
return; //Do not run if we somehow haven't found the list.
}
//unfortunately, SystemEventInvokeInfo is a private class so we can't declare a reference of that type.
//we will use object and then use reflection to get what we need...
List <UserPreferenceChangedEventHandler> listDelegatesToRemove = new List <UserPreferenceChangedEventHandler>();
//this is NOT threadsafe. Unfortunately, if the collection is modified an exception will be thrown during iteration.
// This will happen any time another thread hooks or unhooks the UserPreferenceChanged event while we iterate.
// Modify this to be threadsafe somehow if that is required.
foreach (object oSystemEventInvokeInfo in _UserPreferenceChangedList)
{
UserPreferenceChangedEventHandler oDelegate =
GetDelegateFromSystemEventInvokeInfo(oSystemEventInvokeInfo) as UserPreferenceChangedEventHandler;
if (oDelegate != null && oDelegate.Target == pObjectToUnhook)
{
//at this point we have found an event handler that must be unhooked.
listDelegatesToRemove.Add(oDelegate);
}
}
//We should unhook using the public method because the internal implementation of this event is unknown.
// iterating the private internal list is already shady enough without manipulating it directly...
foreach (UserPreferenceChangedEventHandler itemToRemove in listDelegatesToRemove)
{
SystemEvents.UserPreferenceChanged -= itemToRemove;
}
}
/// <summary>
/// Constructs a new Aero styled form.
/// </summary>
public AeroForm()
{
Font = SystemFonts.MessageBoxFont;
_preferencesHandler = new UserPreferenceChangedEventHandler(SystemEvents_UserPreferenceChanged);
SystemEvents.UserPreferenceChanged += _preferencesHandler;
}
/// <summary>
/// Constructs a new Aero styled form.
/// </summary>
public AeroForm()
{
Font = SystemFonts.MessageBoxFont;
_preferencesHandler = new UserPreferenceChangedEventHandler(SystemEvents_UserPreferenceChanged);
SystemEvents.UserPreferenceChanged += _preferencesHandler;
}
/// <summary>
/// Extends BeginInvoke so that when a state object is not needed, null does not need to be passed.
/// <example>
/// userpreferencechangedeventhandler.BeginInvoke(sender, e, callback);
/// </example>
/// </summary>
public static IAsyncResult BeginInvoke(this UserPreferenceChangedEventHandler userpreferencechangedeventhandler, Object sender, UserPreferenceChangedEventArgs e, AsyncCallback callback)
{
if (userpreferencechangedeventhandler == null)
{
throw new ArgumentNullException("userpreferencechangedeventhandler");
}
return(userpreferencechangedeventhandler.BeginInvoke(sender, e, callback, null));
}
public void SignalsUserPreferenceEventsAsynchronouslyOnThemeChanged()
{
var changing = new AutoResetEvent(false);
var changed = new AutoResetEvent(false);
UserPreferenceChangingEventArgs changingArgs = null;
UserPreferenceChangingEventHandler changingHandler = (o, e) =>
{
changingArgs = e;
changing.Set();
};
List <UserPreferenceChangedEventArgs> changedArgs = new List <UserPreferenceChangedEventArgs>();
UserPreferenceChangingEventArgs changingDuringChanged = null;
UserPreferenceChangedEventHandler changedHandler = (o, e) =>
{
changedArgs.Add(e);
changingDuringChanged = changingArgs;
// signal test to continue after two events were recieved
if (changedArgs.Count > 1)
{
changed.Set();
}
};
SystemEvents.UserPreferenceChanging += changingHandler;
SystemEvents.UserPreferenceChanged += changedHandler;
try
{
SendMessage(User32.WM_THEMECHANGED, 0, null);
Assert.True(changing.WaitOne(PostMessageWait));
Assert.NotNull(changingArgs);
Assert.Equal(UserPreferenceCategory.VisualStyle, changingArgs.Category);
Assert.True(changed.WaitOne(PostMessageWait));
Assert.Equal(2, changedArgs.Count);
Assert.NotNull(changedArgs[0]);
Assert.Equal(UserPreferenceCategory.Window, changedArgs[0].Category);
Assert.NotNull(changedArgs[1]);
Assert.Equal(UserPreferenceCategory.VisualStyle, changedArgs[1].Category);
// changed must follow changing for VisualStyle
Assert.NotNull(changingDuringChanged);
Assert.Equal(UserPreferenceCategory.VisualStyle, changingDuringChanged.Category);
}
finally
{
SystemEvents.UserPreferenceChanging -= changingHandler;
SystemEvents.UserPreferenceChanged -= changedHandler;
changing.Dispose();
changed.Dispose();
}
}
public void SignalsUserPreferenceEventsSynchronouslyOnReflectedThemeChanged()
{
bool changing = false, changed = false;
UserPreferenceChangingEventArgs changingArgs = null;
UserPreferenceChangingEventHandler changingHandler = (o, e) =>
{
changingArgs = e;
changing = true;
};
List <UserPreferenceChangedEventArgs> changedArgs = new List <UserPreferenceChangedEventArgs>();
UserPreferenceChangingEventArgs changingDuringChanged = null;
UserPreferenceChangedEventHandler changedHandler = (o, e) =>
{
changedArgs.Add(e);
changingDuringChanged = changingArgs;
changed = true;
};
SystemEvents.UserPreferenceChanging += changingHandler;
SystemEvents.UserPreferenceChanged += changedHandler;
try
{
SendReflectedMessage(User32.WM_THEMECHANGED, 0, null);
Assert.True(changing);
Assert.NotNull(changingArgs);
Assert.Equal(UserPreferenceCategory.VisualStyle, changingArgs.Category);
Assert.True(changed);
Assert.Equal(2, changedArgs.Count);
Assert.NotNull(changedArgs[0]);
Assert.Equal(UserPreferenceCategory.Window, changedArgs[0].Category);
Assert.NotNull(changedArgs[1]);
Assert.Equal(UserPreferenceCategory.VisualStyle, changedArgs[1].Category);
// changed must follow changing for VisualStyle
Assert.NotNull(changingDuringChanged);
Assert.Equal(UserPreferenceCategory.VisualStyle, changingDuringChanged.Category);
}
finally
{
SystemEvents.UserPreferenceChanging -= changingHandler;
SystemEvents.UserPreferenceChanged -= changedHandler;
}
}
public void SignalsUserPreferenceEventsAsynchronously(int message, int uiAction, string area, UserPreferenceCategory expectedCategory)
{
var changing = new AutoResetEvent(false);
var changed = new AutoResetEvent(false);
UserPreferenceChangingEventArgs changingArgs = null;
UserPreferenceChangingEventHandler changingHandler = (o, e) =>
{
changingArgs = e;
changing.Set();
};
UserPreferenceChangedEventArgs changedArgs = null;
UserPreferenceChangingEventArgs changingDuringChanged = null;
UserPreferenceChangedEventHandler changedHandler = (o, e) =>
{
changedArgs = e;
changingDuringChanged = changingArgs;
changed.Set();
};
SystemEvents.UserPreferenceChanging += changingHandler;
SystemEvents.UserPreferenceChanged += changedHandler;
try
{
SendMessage(message, uiAction, area);
Assert.True(changing.WaitOne(PostMessageWait));
Assert.NotNull(changingArgs);
Assert.Equal(expectedCategory, changingArgs.Category);
Assert.True(changed.WaitOne(PostMessageWait));
Assert.NotNull(changedArgs);
Assert.Equal(expectedCategory, changedArgs.Category);
// changed must follow changing for the same category
Assert.NotNull(changingDuringChanged);
Assert.Equal(expectedCategory, changingDuringChanged.Category);
}
finally
{
SystemEvents.UserPreferenceChanging -= changingHandler;
SystemEvents.UserPreferenceChanged -= changedHandler;
changing.Dispose();
changed.Dispose();
}
}
public void SignalsUserPreferenceEventsSynchronously(int message, int uiAction, string area, UserPreferenceCategory expectedCategory)
{
bool changing = false, changed = false;
UserPreferenceChangingEventArgs changingArgs = null;
UserPreferenceChangingEventHandler changingHandler = (o, e) =>
{
changingArgs = e;
changing = true;
};
UserPreferenceChangedEventArgs changedArgs = null;
UserPreferenceChangingEventArgs changingDuringChanged = null;
UserPreferenceChangedEventHandler changedHandler = (o, e) =>
{
changedArgs = e;
changingDuringChanged = changingArgs;
changed = true;
};
SystemEvents.UserPreferenceChanging += changingHandler;
SystemEvents.UserPreferenceChanged += changedHandler;
try
{
SendReflectedMessage(message, uiAction, area);
Assert.True(changing);
Assert.NotNull(changingArgs);
Assert.Equal(expectedCategory, changingArgs.Category);
Assert.True(changed);
Assert.NotNull(changedArgs);
Assert.Equal(expectedCategory, changedArgs.Category);
// changed must follow changing for the same category
Assert.NotNull(changingDuringChanged);
Assert.Equal(expectedCategory, changingDuringChanged.Category);
}
finally
{
SystemEvents.UserPreferenceChanging -= changingHandler;
SystemEvents.UserPreferenceChanged -= changedHandler;
}
}
/// <summary>
/// Sets handlers for notifying the application of desktop preference changes (taskbar movements, etc.).
/// </summary>
private void SetHandlers()
{
if (this.PreferenceEvent == null && this.PreferenceEventHandler == null)
{
this.PreferenceEvent = new UserPreferenceChanged(this.DesktopPreferenceChangedHandler);
this.PreferenceEventHandler = new UserPreferenceChangedEventHandler(this.PreferenceEvent);
SystemEvents.UserPreferenceChanged += this.PreferenceEventHandler;
}
}
/// <summary>
/// Releases handlers set by SetHandlers().
/// </summary>
private void ReleaseHandlers()
{
if (this.PreferenceEvent != null || this.PreferenceEventHandler != null)
{
SystemEvents.UserPreferenceChanged -= this.PreferenceEventHandler;
this.PreferenceEvent = null;
this.PreferenceEventHandler = null;
}
}
public static void add_UserPreferenceChanged(UserPreferenceChangedEventHandler value)
{
}
public static void add_UserPreferenceChanged (UserPreferenceChangedEventHandler value) {
}
