void CreateContext()
{
hwndSource = (HwndSource)PresentationSource.FromVisual(this.textArea);
if (hwndSource != null)
{
if (isReadOnly)
{
defaultImeWnd = IntPtr.Zero;
currentContext = IntPtr.Zero;
}
else
{
defaultImeWnd = ImeNativeWrapper.ImmGetDefaultIMEWnd(IntPtr.Zero);
currentContext = ImeNativeWrapper.ImmGetContext(defaultImeWnd);
}
previousContext = ImeNativeWrapper.ImmAssociateContext(hwndSource.Handle, currentContext);
hwndSource.AddHook(WndProc);
// UpdateCompositionWindow() will be called by the caret becoming visible
var threadMgr = ImeNativeWrapper.GetTextFrameworkThreadManager();
if (threadMgr != null)
{
// Even though the docu says passing null is invalid, this seems to help
// activating the IME on the default input context that is shared with WPF
threadMgr.SetFocus(IntPtr.Zero);
}
}
}
public void OnLostKeyboardFocus(KeyboardFocusChangedEventArgs e)
{
if (e.OldFocus == textArea && currentContext != IntPtr.Zero)
{
ImeNativeWrapper.NotifyIme(currentContext);
}
ClearContext();
}
public void UpdateCompositionWindow()
{
if (currentContext != IntPtr.Zero)
{
ImeNativeWrapper.SetCompositionFont(hwndSource, currentContext, textArea);
ImeNativeWrapper.SetCompositionWindow(hwndSource, currentContext, textArea);
}
}
void ClearContext()
{
if (hwndSource != null)
{
ImeNativeWrapper.ImmAssociateContext(hwndSource.Handle, previousContext);
ImeNativeWrapper.ImmReleaseContext(defaultImeWnd, currentContext);
currentContext = IntPtr.Zero;
defaultImeWnd = IntPtr.Zero;
hwndSource.RemoveHook(WndProc);
hwndSource = null;
}
}