C# 编程/关键字/is

关键字is 将对象与类型进行比较，如果它们相同或属于相同的“类型”（对象继承该类型），则返回true。因此，该关键字用于检查类型兼容性，通常在强制转换（转换）源类型到目标类型之前，以确保不会抛出类型转换异常。在null 变量上使用is 始终返回false。

此代码片段展示了示例用法

System.IO.StreamReader reader = new StreamReader("readme.txt");
bool b = reader is System.IO.TextReader;

// b is now set to true, because StreamReader inherits TextReader

C# 关键字
abstract as base bool break byte case catch char checked class const continue decimal default delegate do double else enum event explicit extern false finally fixed float for foreach goto if implicit in int interface internal is lock long namespace new null object operator out override params private protected public readonly ref return sbyte sealed short sizeof stackalloc static string struct switch this throw true try typeof uint ulong unchecked unsafe ushort using var virtual void volatile while
C# 特殊标识符（上下文关键字）
add alias async await dynamic get global nameof partial remove set value when where yield
上下文关键字（用于查询）
ascending by descending equals from group in into join let on orderby select where