IL查看泛型

查看泛型的IL

我们在开发中经常用到泛型，下面一起通过IL来查看泛型背后做了那些工作

示例代码

示例代码如下：

using System;

namespace MyCollection
{
    public class GenericExample
    {
        public static T GetT<T>(T value)
        {
            return value;

        }
        public static void Main(string[] args)
        {
            int a = GetT(3);
            string str = GetT("I'am String");
            Console.WriteLine("value1:{0}	 Value2:{1}",a,str);
        }
    }
}

IL查看

通过这可以看到泛型在解释时，也会生成一个新的Class GetT(!!T):!!T

IL代码如下

.method public hidebysig static
    void Main (
        string[] args
    ) cil managed
{
    // Method begins at RVA 0x218c
    // Code size 38 (0x26)
    .maxstack 3
    .entrypoint
    .locals init (
        [0] int32 a,
        [1] string str
    )

    IL_0000: nop
    IL_0001: ldc.i4.3
    //这里的T转成了int32
    IL_0002: call !!0 MyCollection.GenericExample::GetT<int32>(!!0)
    IL_0007: stloc.0
    IL_0008: ldstr "I'am String"
    //而在这儿T的类型又转成了string
    IL_000d: call !!0 MyCollection.GenericExample::GetT<string>(!!0)
    IL_0012: stloc.1
    IL_0013: ldstr "value1:{0}	 Value2:{1}"
    IL_0018: ldloc.0
    IL_0019: box [mscorlib]System.Int32
    IL_001e: ldloc.1
    IL_001f: call void [mscorlib]System.Console::WriteLine(string, object, object)
    IL_0024: nop
    IL_0025: ret
} // end of method GenericExample::Main

泛型在运行时自动转换

通过上面的IL代码可知：泛型在运行时会自动转化类型