Component.cs

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namespace System.ComponentModel;
 
[DesignerCategory("Component")]
public class Component : MarshalByRefObject, IComponent, IDisposable
{
    private static readonly object s_eventDisposed = new object();
 
    private ISite _site;
 
    private EventHandlerList _events;
 
    protected virtual bool CanRaiseEvents => true;
 
    internal bool CanRaiseEventsInternal => CanRaiseEvents;
 
    protected EventHandlerList Events => _events ?? (_events = new EventHandlerList(this));
 
    [Browsable(false)]
    [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
    public virtual ISite? Site
    {
        get
        {
            return _site;
        }
        set
        {
            _site = value;
        }
    }
 
    [Browsable(false)]
    [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
    public IContainer? Container => _site?.Container;
 
    [Browsable(false)]
    [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
    protected bool DesignMode => _site?.DesignMode ?? false;
 
    [Browsable(false)]
    [EditorBrowsable(EditorBrowsableState.Advanced)]
    public event EventHandler? Disposed
    {
        add
        {
            Events.AddHandler(s_eventDisposed, value);
        }
        remove
        {
            Events.RemoveHandler(s_eventDisposed, value);
        }
    }
 
    ~Component()
    {
        Dispose(disposing: false);
    }
 
    public void Dispose()
    {
        Dispose(disposing: true);
        GC.SuppressFinalize(this);
    }
 
    protected virtual void Dispose(bool disposing)
    {
        if (!disposing)
        {
            return;
        }
        lock (this)
        {
            _site?.Container?.Remove(this);
            if (_events != null)
            {
                ((EventHandler)_events[s_eventDisposed])?.Invoke(this, EventArgs.Empty);
            }
        }
    }
 
    protected virtual object? GetService(Type service)
    {
        return _site?.GetService(service);
    }
 
    public override string ToString()
    {
        ISite site = _site;
        if (site == null)
        {
            return GetType().FullName;
        }
        return site.Name + " [" + GetType().FullName + "]";
    }
}