此方法(位于System.Collections命名空间下)用于从堆栈中删除所有对象。此方法会将“堆栈计数”设置为零，并且还会删除对集合元素中其他对象的引用。此方法是O(n)运算，其中n是Count。
句法：
public virtual void Clear ();下面的程序说明了上面讨论的方法的使用：
范例1：
// C# code to illustrate the
// Stack.Clear Method
using System;
using System.Collections;
class GFG {
// Driver code
public static void Main()
{
// Creating a Stack
Stack myStack = new Stack();
// Inserting the elements into the Stack
myStack.Push("1st Element");
myStack.Push("2nd Element");
myStack.Push("3rd Element");
myStack.Push("4th Element");
myStack.Push("5th Element");
myStack.Push("6th Element");
// Displaying the count of elements
// contained in the Stack before
// removing all the elements
Console.Write("Total number of elements"+
" in the Stack are : ");
Console.WriteLine(myStack.Count);
// Removing all elements from Stack
myStack.Clear();
// Displaying the count of elements
// contained in the Stack after
// removing all the elements
Console.Write("Total number of elements"+
" in the Stack are : ");
Console.WriteLine(myStack.Count);
}
}
输出：
Total number of elements in the Stack are : 6
Total number of elements in the Stack are : 0
范例2：
// C# code to illustrate the
// Stack.Clear Method
using System;
using System.Collections;
class GFG {
// Driver code
public static void Main()
{
// Creating a Stack
Stack myStack = new Stack();
// Inserting the elements into the Stack
myStack.Push(3);
myStack.Push(5);
myStack.Push(7);
myStack.Push(9);
myStack.Push(11);
// Displaying the count of elements
// contained in the Stack before
// removing all the elements
Console.Write("Total number of elements "+
"in the Stack are : ");
Console.WriteLine(myStack.Count);
// Removing all elements from Stack
myStack.Clear();
// Displaying the count of elements
// contained in the Stack after
// removing all the elements
Console.Write("Total number of elements"+
" in the Stack are : ");
Console.WriteLine(myStack.Count);
}
}
输出：
Total number of elements in the Stack are : 5
Total number of elements in the Stack are : 0
参考：
- https://docs.microsoft.com/zh-cn/dotnet/api/system.collections.stack.clear?view=netframework-4.7.2