public static readonly RoutedEvent CheckedEvent;
public static readonly RoutedEvent UncheckedEvent;
public static readonly RoutedEvent IndeterminateEvent;
public static readonly DependencyProperty IsCheckedProperty;
public static readonly DependencyProperty IsThreeStateProperty;
public ToggleButton();
public bool IsThreeState { get; set; }
public bool? IsChecked { get; set; }
public event RoutedEventHandler Checked;
public event RoutedEventHandler Indeterminate;
public event RoutedEventHandler Unchecked;
public override string ToString();
protected virtual void OnChecked(RoutedEventArgs e);
protected override void OnClick();
protected override AutomationPeer OnCreateAutomationPeer();
protected virtual void OnIndeterminate(RoutedEventArgs e);
protected virtual void OnUnchecked(RoutedEventArgs e);
protected internal virtual void OnToggle();
ToggleButton基类提供了两个属性和三个事件
IsThreeState属性为true表示控件支持3个状态，IsChecked属性为true表示当前控件已被选中。Checked事件表示选中时引发的事件，Unchecked事件表示从选中状态改为未选状态时引发的事件，Indeterminate事件表示不确定状态时引发的事件
