ThreadLocal

public class Test2
{
    private List<string> lst1;
    public Test2()
    {
        lst1 = new List<string>();
    }

    public List<string> getList()
    {
        return lst1;
    }
    public void setList(List<string> l)
    {
        lst1 = l;

    }
}

调用:创建一个Test2对象，给里面的lst1赋值，启动一个线程，也给里面的lst1再赋值。

        ThreadLocalTest.Test2 t11 = new ThreadLocalTest.Test2();
        t11.setList(new List<string>() { "a1", "b1", "c1" });

        Thread t = new Thread(() =>
        {
            t11.setList(new List<string>() { "aa", "bb", "cc" });
            foreach (string a in t11.getList())
            {
                Console.WriteLine("Thread:" + a);
            }
        });
        t.Start();
        t.Join();

        foreach (string a in t11.getList())
        {
            Console.WriteLine(a);
        }

image.png

从结果看没什么特别，新的赋值把旧的赋值覆盖掉了。
---------------------分割线------------------------
这次将List<string>用ThreadLocal来定义。
例子1：

public class Test1
{
    private readonly ThreadLocal<List<string>> _localCtx = new ThreadLocal<List<string>>(() => new List<string>());

    public List<string> getList()
    {
        return _localCtx.Value;
    }
    public void setList(List<string> l)
    {
        _localCtx.Value = l;

    }
}

调用：

        ThreadLocalTest.Test1 t1 = new ThreadLocalTest.Test1();
        t1.setList(new List<string>() { "a", "b", "c" });

        Thread t = new Thread(() => {
            t1.setList(new List<string>() { "aa", "bb", "cc" });
            foreach (string a in t1.getList())
            {
                Console.WriteLine("Thread:"+a);
            }
        });
        t.Start();
        t.Join();
        foreach (string a in t1.getList())
        {
            Console.WriteLine(a);
        }

image.png

例子2：

    static void Main(string[] args)
    {
        ConsoleApplication37.Test1 t1 = new ConsoleApplication37.Test1();
        List<string> l = t1.getList();
        l.Add("a");
        l.Add("b");
        l.Add("c");
        Thread t = new Thread(() =>
        {
            List<string> l2 = t1.getList();
            l2.Add("a2");
            l2.Add("b2");
            l2.Add("c2");
            foreach (string a in t1.getList())
            {
                Console.WriteLine("Thread:" + a);
            }
        });
        t.Start();
        t.Join();
        foreach (string a in t1.getList())
        {
            Console.WriteLine(a);
        }
    }

image.png

用了ThreadLocal，哪怕是同一个对象，如果调用对象的是不同的线程，ThreadLocal也会new一个新的内部属性。