本文整理汇总了C#中System.Linq.Queryable.Single方法的典型用法代码示例。如果您正苦于以下问题:C# Queryable.Single方法的具体用法?C# Queryable.Single怎么用?C# Queryable.Single使用的例子?那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。
在下文中一共展示了Queryable.Single方法的3个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的C#代码示例。
示例1:
// Create two arrays.
string[] fruits1 = { "orange" };
string[] fruits2 = { "orange", "apple" };
// Get the only item in the first array.
string fruit1 = fruits1.AsQueryable().Single();
Console.WriteLine("First query: " + fruit1);
try
{
// Try to get the only item in the second array.
string fruit2 = fruits2.AsQueryable().Single();
Console.WriteLine("Second query: " + fruit2);
}
catch (System.InvalidOperationException)
{
Console.WriteLine(
"Second query: The collection does not contain exactly one element."
);
}
输出:
First query: orange Second query: The collection does not contain exactly one element
示例2:
string[] fruits = { "apple", "banana", "mango",
"orange", "passionfruit", "grape" };
// Get the only string in the array whose length is greater than 10.
string fruit1 = fruits.AsQueryable().Single(fruit => fruit.Length > 10);
Console.WriteLine("First Query: " + fruit1);
try
{
// Try to get the only string in the array
// whose length is greater than 15.
string fruit2 = fruits.AsQueryable().Single(fruit => fruit.Length > 15);
Console.WriteLine("Second Query: " + fruit2);
}
catch (System.InvalidOperationException)
{
Console.Write("Second Query: The collection does not contain ");
Console.WriteLine("exactly one element whose length is greater than 15.");
}
输出:
First Query: passionfruit Second Query: The collection does not contain exactly one element whose length is greater than 15.
示例3: Main
//引入命名空间
using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.Linq;
public class MainClass{
public static void Main(){
int[] numbers = {1, 2, 3, 4, 5, 6, 7, 8, 9};
var query = numbers.Single(n => n > 8);
Console.Write(query);
}
}