private void HandleKeyDown()
        {
            if (!string.IsNullOrEmpty(this.DisplayKey))
            {
                if (this.DisplayKey.ToUpper() == "C")
                {
                    IInputElement targetelement = Keyboard.FocusedElement;
                    if (targetelement != null)
                    {
                        if (targetelement as TextBox != null)
                        {
                            (targetelement as TextBox).Text = string.Empty;
                        }
                        else if (targetelement as PasswordBox != null)
                        {
                            (targetelement as PasswordBox).Password = string.Empty;
                        }
                    }
                    return;
                }

                for (int i = 0; i < this.DisplayKey.Length; i++)
                {
                    SoftKeyboardManager.PressSoftKey(this.DisplayKey[i] + "");
                }
            }
        }
        void HandleKeyDown()
        {
            if (!string.IsNullOrEmpty(this.DisplayKey))
            {
                if (this.DisplayKey == "Shift" && this.ParentKeyboard != null)
                {
                    this.ParentKeyboard.IsShiftPressed = !this.ParentKeyboard.IsShiftPressed;
                    return;
                }

                if (this.ParentKeyboard == null)
                {
                    SoftKeyboardManager.PressSoftKey(this.DisplayKey, this.EffectiveKey, this.IsShiftPressed, this.IsCapsLock);
                }
                else
                {
                    SoftKeyboardManager.PressSoftKey(this.DisplayKey, this.EffectiveKey, this.ParentKeyboard.IsShiftPressed, this.ParentKeyboard.IsCapsLock);
                }
            }
        }