本文整理汇总了C#中System.Linq.Lookup<TKey,TElement>类的典型用法代码示例。如果您正苦于以下问题：C# Lookup<TKey,TElement>类的具体用法？C# Lookup<TKey,TElement>怎么用？C# Lookup<TKey,TElement>使用的例子？那么, 这里精选的类代码示例或许可以为您提供帮助。
Lookup<TKey,TElement>类属于System.Linq命名空间，在下文中一共展示了Lookup<TKey,TElement>类的1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: LookupExample
class Package
{
public string Company;
public double Weight;
public long TrackingNumber;
}
public static void LookupExample()
{
// Create a list of Packages to put into a Lookup data structure.
List<Package> packages = new List<Package> { new Package { Company = "Coho Vineyard", Weight = 25.2, TrackingNumber = 89453312L },
new Package { Company = "Lucerne Publishing", Weight = 18.7, TrackingNumber = 89112755L },
new Package { Company = "Wingtip Toys", Weight = 6.0, TrackingNumber = 299456122L },
new Package { Company = "Contoso Pharmaceuticals", Weight = 9.3, TrackingNumber = 670053128L },
new Package { Company = "Wide World Importers", Weight = 33.8, TrackingNumber = 4665518773L } };
// Create a Lookup to organize the packages. Use the first character of Company as the key value.
// Select Company appended to TrackingNumber for each element value in the Lookup.
Lookup<char, string> lookup = (Lookup<char, string>)packages.ToLookup(p => Convert.ToChar(p.Company.Substring(0, 1)),
p => p.Company + " " + p.TrackingNumber);
// Iterate through each IGrouping in the Lookup and output the contents.
foreach (IGrouping<char, string> packageGroup in lookup)
{
// Print the key value of the IGrouping.
Console.WriteLine(packageGroup.Key);
// Iterate through each value in the IGrouping and print its value.
foreach (string str in packageGroup)
Console.WriteLine(" {0}", str);
}
// This code produces the following output:
//
// C
// Coho Vineyard 89453312
// Contoso Pharmaceuticals 670053128
// L
// Lucerne Publishing 89112755
// W
// Wingtip Toys 299456122
// Wide World Importers 4665518773
// Get the number of key-collection pairs in the Lookup.
int count = lookup.Count;
// Select a collection of Packages by indexing directly into the Lookup.
IEnumerable<string> cgroup = lookup['C'];
// Output the results.
Console.WriteLine("\nPackages that have a key of 'C':");
foreach (string str in cgroup)
Console.WriteLine(str);
// This code produces the following output:
//
// Packages that have a key of 'C'
// Coho Vineyard 89453312
// Contoso Pharmaceuticals 670053128
// Determine if there is a key with the value 'G' in the Lookup.
bool hasG = lookup.Contains('G');
}