msdn 上一个关于线程锁的问题,有代码

[我看你有戏]

// statements_lock2.cs
using System;
using System.Threading;

class Account 
{
	int balance;

	Random r = new Random();

	private static object obj = new object();

	public Account(int initial) 
	{
		balance = initial;
	}

	int Withdraw(int amount) 
	{

		// This condition will never be true unless the lock statement
		// is commented out:
		if (balance < 0) 
		{
			throw new Exception("Negative Balance");
		}

		// Comment out the next line to see the effect of leaving out 
		// the lock keyword:
		//lock (this)
		lock(obj)
		{
			if (balance >= amount) 
			{
				Console.WriteLine("Balance before Withdrawal :  " + balance);
				Console.WriteLine("Amount to Withdraw        : -" + amount); 
				balance = balance - amount;
				Console.WriteLine("Balance after Withdrawal  :  " + balance);
				return amount;
			}
			else 
			{
				return 0; // transaction rejected
			}
		}
	}

	public void DoTransactions() 
	{
		for (int i = 0; i < 100; i++) 
		{
			Withdraw(r.Next(1, 100));
		}
	}
}

class Test 
{
	public static void Main() 
	{
		Thread[] threads = new Thread[10];
		Account acc = new Account (1000);
		for (int i = 0; i < 10; i++) 
		{
			Thread t = new Thread(new ThreadStart(acc.DoTransactions));
			threads[i] = t;
		}
		for (int i = 0; i < 10; i++) 
		{
			threads[i].Start();
		}
	}
}

我把 lock (this) 用lock(obj)代替，也起到了线程锁的作用，

能否告诉我一下，lock(obj)有什么好处没

网上也有说法但是我不太明白

谢谢了

[ztenv]

lock(this)锁住了整个类对象，
lock(obj)以锁住的只是obj，此是可以访问this的其它对象

[fengjian_428]

1L说的对