我认为，ArrayList和List<T>之间的区别是:

List<T>, where T is value-type is faster than ArrayList. This is because List<T> avoids boxing/unboxing (where T is value-type). Many sources say - usually ArrayList used just for backward compatibility. (is not a real difference, but i think it is important note). Reflection is easier with nongeneric ArrayList then List<T> ArrayList has IsSynchronized property. So, It is easy to create and use syncronised ArrayList. I didin't found IsSynchronized property for List<T>. Also Keep in mind this type of synchronization is relatively inefficient, msdn): var arraylist = new ArrayList(); var arrayListSyncronized = ArrayList.Synchronized(arraylist Console.WriteLine($"syncronized {arraylist.IsSynchronized}"); Console.WriteLine($"syncronized {arrayListSyncronized.IsSynchronized}"); var list = new List<object>(); var listSyncronized = ArrayList.Synchronized(list); Console.WriteLine($"syncronized {list.IsSynchronized}");//error, no such prop Console.WriteLine($"syncronized {list.IsSynchronized}");//error, no such prop ArrayList has ArrayList.SyncRoot property which can be used for syncronisation (msdn). List<T> hasn't SyncRoot property, so in the following construction you need to use some object if you use List<T>: ArrayList myCollection = new ArrayList(); lock(myCollection.SyncRoot) // ofcourse you can use another object for this goal { foreach (object item in myCollection) { // ... } }

ArrayList不是类型安全的，而List<T>是类型安全的。简单:)。

我认为，ArrayList和List<T>之间的区别是:

List<T>, where T is value-type is faster than ArrayList. This is because List<T> avoids boxing/unboxing (where T is value-type). Many sources say - usually ArrayList used just for backward compatibility. (is not a real difference, but i think it is important note). Reflection is easier with nongeneric ArrayList then List<T> ArrayList has IsSynchronized property. So, It is easy to create and use syncronised ArrayList. I didin't found IsSynchronized property for List<T>. Also Keep in mind this type of synchronization is relatively inefficient, msdn): var arraylist = new ArrayList(); var arrayListSyncronized = ArrayList.Synchronized(arraylist Console.WriteLine($"syncronized {arraylist.IsSynchronized}"); Console.WriteLine($"syncronized {arrayListSyncronized.IsSynchronized}"); var list = new List<object>(); var listSyncronized = ArrayList.Synchronized(list); Console.WriteLine($"syncronized {list.IsSynchronized}");//error, no such prop Console.WriteLine($"syncronized {list.IsSynchronized}");//error, no such prop ArrayList has ArrayList.SyncRoot property which can be used for syncronisation (msdn). List<T> hasn't SyncRoot property, so in the following construction you need to use some object if you use List<T>: ArrayList myCollection = new ArrayList(); lock(myCollection.SyncRoot) // ofcourse you can use another object for this goal { foreach (object item in myCollection) { // ... } }

ArrayList是不同类型数据的集合，而List<>是其自身依赖的相似类型数据的集合。

是的，差不多。List<T>是泛型类。它支持存储特定类型的值，而不强制转换为对象(当T是ArrayList情况下的值类型时，这会引起装箱/拆箱开销)。ArrayList仅存储对象引用。作为一个泛型集合，List<T>实现了泛型IEnumerable<T>接口，可以很容易地在LINQ中使用(不需要任何Cast或OfType调用)。

ArrayList属于c#没有泛型的时代。不赞成使用List<T>。你不应该在以。net >= 2.0为目标的新代码中使用ArrayList，除非你必须与使用它的旧API进行交互。

如.NET Framework文档中所述

我们不建议你将数组列表类用于new 发展。相反，我们建议您使用通用的List<T> 类。ArrayList类被设计用来保存异构类 对象的集合。然而，它并不总是提供最好的 的性能。相反，我们建议如下: 对于异构对象集合，使用List<Object>(在c#中)或List(of Object)(在Visual Basic中)类型。 对于对象的同构集合，使用List<T>类。

请参见不应使用非泛型集合