锁定字符串不是一个好主意，我建议两个选择：

Locking on a string is not a good idea. I suggest two alternatives:

1. 使用字典< int，object> 作为padLocks类型，并将一个 ）; 作为值。


2. 创建一个简单地保存id的类;

1. Use a Dictionary<int,object> as padLocks' type, and put a new object(); as the value.
2. Create a class that simply holds the id; this would be better for readability if you ever want to look at your LockPad class while debugging.

LockPad类：

class LockPad {
    public int Id { get; private set; }

    public LockPad(int id) {
        this.Id = id;
    }

    public override string ToString() {
        return "lock of " + id.ToString();
    }
}

然后锁定该类。