private void InvokeBack(NavigationBackingOrForwardingEventArgs earg)
{
if (PageBacking == null)
{
return;
}
var lt = PageBacking.GetInvocationList().Reverse();
foreach (EventHandler <NavigationBackingOrForwardingEventArgs> one in lt)
{
one.Invoke(this, earg);
}
}
/// <summary>
/// 当此页处于活动状态并占用整个窗口时，在每次
/// 击键(包括系统键，如 Alt 组合键)时调用。 用于检测页之间的键盘
/// 导航(即使在页本身没有焦点时)。
/// </summary>
/// <param name="sender">触发事件的实例。</param>
/// <param name="e">描述导致事件的条件的事件数据。</param>
private void CoreDispatcher_AcceleratorKeyActivated(CoreDispatcher sender, AcceleratorKeyEventArgs e)
{
if (!e.Handled)
{
var virtualKey = e.VirtualKey;
// 仅当按向左、向右或专用上一页或下一页键时才进一步
// 调查
if ((e.EventType == CoreAcceleratorKeyEventType.SystemKeyDown ||
e.EventType == CoreAcceleratorKeyEventType.KeyDown) &&
(virtualKey == VirtualKey.Left || virtualKey == VirtualKey.Right ||
(int)virtualKey == 166 || (int)virtualKey == 167))
{
var coreWindow = Window.Current.CoreWindow;
var downState = CoreVirtualKeyStates.Down;
bool menuKey = (coreWindow.GetKeyState(VirtualKey.Menu) & downState) == downState;
bool controlKey = (coreWindow.GetKeyState(VirtualKey.Control) & downState) == downState;
bool shiftKey = (coreWindow.GetKeyState(VirtualKey.Shift) & downState) == downState;
bool noModifiers = !menuKey && !controlKey && !shiftKey;
bool onlyAlt = menuKey && !controlKey && !shiftKey;
if (((int)virtualKey == 166 && noModifiers) ||
(virtualKey == VirtualKey.Left && onlyAlt))
{
// 在按上一页键或 Alt+向左键时向后导航
e.Handled = true;
var ev = new NavigationBackingOrForwardingEventArgs(NavigationBackingOrForwardingEventArgs.NavigationEventSource.Mouse);
InvokeBack(ev);
if (!ev.Handled)
{
this.GoBackCommand.Execute(null);
}
}
else if (((int)virtualKey == 167 && noModifiers) ||
(virtualKey == VirtualKey.Right && onlyAlt))
{
// 在按下一页键或 Alt+向右键时向前导航
e.Handled = true;
var ev = new NavigationBackingOrForwardingEventArgs(NavigationBackingOrForwardingEventArgs.NavigationEventSource.Mouse)
{
IsForward = true
};
PageBacking?.Invoke(this, ev);
if (!ev.Handled)
{
this.GoForwardCommand.Execute(null);
}
}
}
}
}
/// <summary>
/// 在按下硬件“后退”按钮时调用。仅适用于 Windows Phone。
/// </summary>
/// <param name="sender">触发事件的实例。</param>
/// <param name="e">描述导致事件的条件的事件数据。</param>
private void HardwareButtons_BackPressed(object sender, BackRequestedEventArgs e)
{
if (!e.Handled)
{
var ev = new NavigationBackingOrForwardingEventArgs(NavigationBackingOrForwardingEventArgs.NavigationEventSource.System);
InvokeBack(ev);
if (!ev.Handled)
{
if (this.GoBackCommand.CanExecute(null))
{
e.Handled = true;
this.GoBackCommand.Execute(null);
}
}
else
{
e.Handled = true;
}
}
}
/// <summary>
/// 当此页处于活动状态并占用整个窗口时，在每次鼠标单击、触摸屏点击
/// 或执行等效交互时调用。 用于检测浏览器样式下一页和
/// 上一步鼠标按钮单击以在页之间导航。
/// </summary>
/// <param name="sender">触发事件的实例。</param>
/// <param name="e">描述导致事件的条件的事件数据。</param>
private void CoreWindow_PointerPressed(CoreWindow sender, PointerEventArgs e)
{
if (/*!e.Handled*/ true)
{
var properties = e.CurrentPoint.Properties;
// 忽略与鼠标左键、右键和中键的键关联
if (properties.IsLeftButtonPressed || properties.IsRightButtonPressed ||
properties.IsMiddleButtonPressed)
{
return;
}
// 如果按下后退或前进(但不是同时)，则进行相应导航
bool backPressed = properties.IsXButton1Pressed;
bool forwardPressed = properties.IsXButton2Pressed;
if (backPressed ^ forwardPressed)
{
e.Handled = true;
var ev = new NavigationBackingOrForwardingEventArgs(NavigationBackingOrForwardingEventArgs.NavigationEventSource.Mouse);
InvokeBack(ev);
if (!ev.Handled)
{
if (backPressed)
{
this.GoBackCommand.Execute(null);
}
if (forwardPressed)
{
ev.IsForward = true;
this.GoForwardCommand.Execute(null);
}
}
}
}
}