c#系列 list详情

private static readonly T[] s_emptyArray = new T[0];
public List()
{
  this._items = List<T>.s_emptyArray;
}

public void Add(T item)
{
  ++this._version;
  T[] items = this._items;
  int size = this._size;
  if ((uint) size < (uint) items.Length)
  {
 this._size = size + 1;
 items[size] = item;
  }
  else
 this.AddWithResize(item);
}

private void AddWithResize(T item)
{
  int size = this._size;
  this.EnsureCapacity(size + 1);
  this._size = size + 1;
  this._items[size] = item;
}

private void EnsureCapacity(int min)
{
  if (this._items.Length >= min)
 return;
  int num = this._items.Length == 0 ? 4 : this._items.Length * 2;
  if ((uint) num > 2146435071U)
 num = 2146435071;
  if (num < min)
 num = min;
  this.Capacity = num;
}

if (this._items.Length >= min)
 return;

 this.Capacity = num;

public int Capacity
{
 get => _items.Length;
 set
 {
  if (value < _size)
  {
   ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument.value, ExceptionResource.ArgumentOutOfRange_SmallCapacity);
  }

  if (value != _items.Length)
  {
   if (value > 0)
   {
    T[] newItems = new T[value];
    if (_size > 0)
    {
     Array.Copy(_items, newItems, _size);
    }
    _items = newItems;
   }
   else
   {
    _items = s_emptyArray;
   }
  }
 }
}

public bool Remove(T item)
{
 int index = IndexOf(item);
 if (index >= 0)
 {
  RemoveAt(index);
  return true;
 }

 return false;
}

public int IndexOf(T item)
 => Array.IndexOf(_items, item, 0, _size);

int IList.IndexOf(object? item)
{
 if (IsCompatibleObject(item))
 {
  return IndexOf((T)item!);
 }
 return -1;
}

private static bool IsCompatibleObject(object? value)
{
 // Non-null values are fine.  Only accept nulls if T is a class or Nullable<U>.
 // Note that default(T) is not equal to null for value types except when T is Nullable<U>.
 return (value is T) || (value == null && default(T) == null);
}

static void Main(string[] args)
{
 List<object> lists = new List<object>();

 lists.Add(null);

 Console.WriteLine(lists.Count);

 lists.Remove(null);
 Console.ReadLine();
}

public void RemoveAt(int index)
{
 if ((uint)index >= (uint)_size)
 {
  ThrowHelper.ThrowArgumentOutOfRange_IndexException();
 }
 _size--;
 if (index < _size)
 {
  Array.Copy(_items, index + 1, _items, index, _size - index);
 }
 if (RuntimeHelpers.IsReferenceOrContainsReferences<T>())
 {
  _items[_size] = default!;
 }
 _version++;
}

internal Enumerator(List<T> list)
{
 _list = list;
 _index = 0;
 _version = list._version;
 _current = default;
}

public void Dispose()
{
}

public bool MoveNext()
{
 List<T> localList = _list;

 if (_version == localList._version && ((uint)_index < (uint)localList._size))
 {
  _current = localList._items[_index];
  _index++;
  return true;
 }
 return MoveNextRare();
}

private bool MoveNextRare()
{
 if (_version != _list._version)
 {
  ThrowHelper.ThrowInvalidOperationException_InvalidOperation_EnumFailedVersion();
 }

 _index = _list._size + 1;
 _current = default;
 return false;
}

static void Main(string[] args)
{
 List<object> lists = new List<object>();

 lists.Add("123456");

 lists.Add("1231246");

 lists.Add("dsadadsads");

 lists.Add("eqewqew");

 foreach (var item in lists)
 {
  if (item.ToString() == "1231246")
  {
   lists.Remove(item);
  }
 }

 Console.ReadLine();
}

public int Count => _size;