从System.Threading.Timer在UI中调用时如何避免泄漏句柄？

using System;
using System.Threading;
using System.Windows.Forms;

public class TimerExample : Form
{
    private System.Threading.Timer timer;
    private WeakReference<System.Threading.Timer> timerWeakRef;

    public TimerExample()
    {
        timer = new System.Threading.Timer(OnTimerElapsed, null, 1000, 5000);
        timerWeakRef = new WeakReference<System.Threading.Timer>(timer);
    }

    private void OnTimerElapsed(object state)
    {
        // 执行定时操作
    }

    protected override void OnFormClosing(FormClosingEventArgs e)
    {
        base.OnFormClosing(e);

        if (timerWeakRef.TryGetTarget(out var target))
        {
            target.Dispose();
        }
    }
}