我有一个类是这样的:
public static class Messenger<T>
{
private static readonly Dictionary<string, Delegate> eventTable = new Dictionary<string, Delegate>();
public static void DoSomethingWithEventTable() //Somehow fills eventTable
public static void Clear()
{
eventTable.Clear();
}
}
现在,我调用了DoSomethingWithEventTable
在我的程序中的某个地方两次,如下所示:
Messenger<int>.DoSomethingWithEventTable();
Messenger<float>.DoSomethingWithEventTable();
我要清除eventTable
对于每个 Messenger<T>
。我该怎么做呢?我应该打电话Clear
对于我放入泛型中的每种类型,如下所示:
Messenger<int>.Clear();
Messenger<float>.Clear();
或者做一次这样的傻事就足够了:
Messenger<string>.Clear();
UPD:基本实验表明我应该清除每个使用过的 T 的 Messenger。现在有人可以为这些类提供更好的设计吗?
我现在使用的更详细版本:
static public class Messenger<T>
{
private static readonly Dictionary<string, Delegate> eventTable = new Dictionary<string, Delegate>();
static public void AddListener(string eventType, Callback<T> handler)
{
// Obtain a lock on the event table to keep this thread-safe.
lock (eventTable)
{
// Create an entry for this event type if it doesn't already exist.
if (!eventTable.ContainsKey(eventType))
{
eventTable.Add(eventType, null);
}
// Add the handler to the event.
eventTable[eventType] = (Callback<T>)eventTable[eventType] + handler;
}
}
static public void RemoveListener(string eventType, Callback<T> handler)
{
// Obtain a lock on the event table to keep this thread-safe.
lock (eventTable)
{
// Only take action if this event type exists.
if (eventTable.ContainsKey(eventType))
{
// Remove the event handler from this event.
eventTable[eventType] = (Callback<T>)eventTable[eventType] - handler;
// If there's nothing left then remove the event type from the event table.
if (eventTable[eventType] == null)
{
eventTable.Remove(eventType);
}
}
}
}
static public void Invoke(string eventType, T arg1)
{
Delegate d;
// Invoke the delegate only if the event type is in the dictionary.
if (eventTable.TryGetValue(eventType, out d))
{
// Take a local copy to prevent a race condition if another thread
// were to unsubscribe from this event.
Callback<T> callback = (Callback<T>)d;
// Invoke the delegate if it's not null.
if (callback != null)
{
callback(arg1);
}
}
}
static public void Clear()
{
eventTable.Clear();
}
}
我还有另一门课也很重要Messenger
(非通用,是的)和 Messenger<T,M>
,也许有一天我什至需要像 Messenger<T,M,N>
这样的东西等
最佳答案
每个Messenger<T>
type 将有它自己的 eventTable 副本,因此您需要为您使用的每个不同的 T 调用 Clear()。
如本次测试所示:
[TestFixture]
public class Tests
{
static class MyClass<T>
{
public static List<int> Member = new List<int>();
}
[Test]
public void StaticTest()
{
var m1 = MyClass<int>.Member;
var m2 = MyClass<string>.Member;
Assert.AreNotSame(m1, m2);
}
}
关于c# - 我应该如何清除通用静态类中的字段?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/13082007/