问我可以在wp7中停止硬件的后退按钮吗？

EN

bool flag = false;

// Assuming this is where you can handle executions during loading
loading()
{
    flag = true;
}

// After loading is completed
loadComplete()
{
    flag = false;
}

// Handle back button
protected override void OnBackKeyPress(System.ComponentModel.CancelEventArgs e)
{
    if (flag)
    {
         e.Cancel = true;
    }
}

<phone:PhoneApplicationPage
.....
BackKeyPress="PhoneApplicationPage_BackKeyPress">

 private void PhoneApplicationPage_BackKeyPress(object sender, System.ComponentModel.CancelEventArgs e)
    {
        e.Cancel = CouldStepBack();
    }

 private bool CouldStepBack()
 {
    // todo return true, when load comleted
    // else return false
 }

protected override void OnNavigatedTo(NavigationEventArgs e)
    {
        if (NavigationService.CanGoBack)
        {
            while (NavigationService.RemoveBackEntry() != null)
            {
                NavigationService.RemoveBackEntry();
            }
        }
        base.OnNavigatedTo(e);
    }