ReadOnlyCollection<T>.IndexOf(T) 方法

定义

搜索指定的对象,并返回整个 ReadOnlyCollection<T> 中第一个匹配项的从零开始的索引。Searches for the specified object and returns the zero-based index of the first occurrence within the entire ReadOnlyCollection<T>.

public:
 virtual int IndexOf(T value);
public int IndexOf (T value);
abstract member IndexOf : 'T -> int
override this.IndexOf : 'T -> int
Public Function IndexOf (value As T) As Integer

参数

value
T

要在 List<T> 中定位的对象。The object to locate in the List<T>. 对于引用类型,该值可以为 nullThe value can be null for reference types.

返回

Int32

如果找到,则为整个 itemReadOnlyCollection<T> 第一个匹配项的从零开始的索引;否则为 -1。The zero-based index of the first occurrence of item within the entire ReadOnlyCollection<T>, if found; otherwise, -1.

实现

注解

ReadOnlyCollection<T>向前搜索从第一个元素开始,到最后一个元素结束。The ReadOnlyCollection<T> is searched forward starting at the first element and ending at the last element.

此方法使用默认比较器确定相等性 EqualityComparer<T>.DefaultThis method determines equality using the default comparer EqualityComparer<T>.Default.

此方法执行线性搜索;因此,此方法是 O (n) 操作,其中 nCountThis method performs a linear search; therefore, this method is an O(n) operation, where n is Count.

适用于

另请参阅