此方法(位于System.Collections命名空间下)用于在不删除对象的情况下返回堆栈顶部的对象。此方法类似于Pop方法，但是Peek不会修改Stack。
用法:
public virtual object Peek ();
返回值：它返回堆栈顶部的对象。
异常：在空堆栈上调用Peek()方法将引发InvalidOperationException。因此，在使用Peek()方法检索元素之前，请始终检查堆栈中的元素。
下面给出了一些示例，以更好地理解实现。
示例1:
// C# code to illustrate the
// Stack.Peek 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
Console.Write("Total number of elements"+
" in the Stack are : ");
Console.WriteLine(myStack.Count);
// Displaying the top element of Stack
// without removing it from the Stack
Console.WriteLine("Element at the top is : "
+ myStack.Peek());
// Displaying the top element of Stack
// without removing it from the Stack
Console.WriteLine("Element at the top is : "
+ myStack.Peek());
// Displaying the count of elements
// contained in the Stack
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 Element at the top is : 6th Element Element at the top is : 6th Element Total number of elements in the Stack are : 6
示例2:
// C# code to illustrate the
// Stack.Peek Method
using System;
using System.Collections;
class GFG {
// Driver code
public static void Main()
{
// Creating a Stack
Stack myStack = new Stack();
// Displaying the top element of Stack
// without removing it from the Stack
// Calling Peek() method on empty stack
// will throw InvalidOperationException.
Console.WriteLine("Element at the top is : "
+ myStack.Peek());
}
}运行时错误：
Unhandled Exception:
System.InvalidOperationException: Stack empty.
参考：
相关用法
注：本文由纯净天空筛选整理自Kirti_Mangal大神的英文原创作品 Stack.Peek Method in C#。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。