这取决于你需要如何执行。如果您可以接受 O（N）的表现，您可以执行以下操作：

It depends on how you need it to perform. If you can accept O(N) performance, you could just do something like:

foreach(var pair in clients) {
    if(pair.Value == expected) {
        clients.Remove(pair.Key);
        break;
    }
}

然而，如果你需要更快，你需要两个字典 - 一个与另一个相反（即由实例锁定）。因此，添加时，您可以：

However, if you need faster you would need two dictionaries - one the reverse of the other (i.e. keyed by the instances). So when adding, you would do:

clientsByKey.Add(key, value);
clientsByValue.Add(value, key);

，以便您可以执行（按值移除）：

so you can do (to remove-by-value):

string key;
if(clientsByValue.TryGetValue(value, out key)) {
    clientsByValue.Remove(value);
    clientsByKey.Remove(key);
}

或类似（按键删除）：

Foo value;
if(clientsByKey.TryGetValue(key, out value)) {
    clientsByValue.Remove(value);
    clientsByKey.Remove(key);
}