在《.NET框架程序设计》中有这样的一个例子：
using System;
struct Point : ICloneable
{
public Int32 x, y;
public override String ToString()
{
return String.Format("({0}, {1}", x, y);
}
public Object Clone()
{
return MemberwiseClone();
}
}
public class App
{
public static void Main()
{
Point p;
p.x = 10;
p.y = 20;
Console.WriteLine(p.ToString());
Console.WriteLine(p.GetType());
Point p2 = (Point)p.Clone();
ICloneable c = p2;
Object o = c.Clone();
p = (Point)o;
}
}
里面提到p在执行ToString方法的时候不会发生装箱。通过看IL代码确实是这么回事，但是再去查看Point的ToString方法的IL代码，发现在其中进行了装箱操作，那么是不是总的说来还是进行了装箱操作呢？
IL代码如下：
.method public hidebysig virtual instance string
ToString() cil managed
{
// Code size 37 (0x25)
.maxstack 3
.locals init (string V_0)
IL_0000: ldstr "({0}, {1}"
IL_0005: ldarg.0
IL_0006: ldfld int32 Point::x
IL_000b: box [mscorlib]System.Int32
IL_0010: ldarg.0
IL_0011: ldfld int32 Point::y
IL_0016: box [mscorlib]System.Int32
IL_001b: call string [mscorlib]System.String::Format(string,
object,
object)
IL_0020: stloc.0
IL_0021: br.s IL_0023
IL_0023: ldloc.0
IL_0024: ret
} // end of method Point::ToString
请各位高手指教。
using System; struct Point : ICloneable { public Int32 x, y; public override String ToString() { return String.Format("({0}, {1}", x, y); } public Object Clone() { return MemberwiseClone(); }} public class App { public static void Main() { Point p; p.x = 10; p.y = 20; Console.WriteLine(p.ToString()); Console.WriteLine(p.GetType()); Point p2 = (Point)p.Clone(); ICloneable c = p2; Object o = c.Clone(); p = (Point)o; }}里面提到p在执行ToString方法的时候不会发生装箱。通过看IL代码确实是这么回事，但是再去查看Point的ToString方法的IL代码，发现在其中进行了装箱操作，那么是不是总的说来还是进行了装箱操作呢？
IL代码如下：
.method public hidebysig virtual instance string
ToString() cil managed
{
// Code size 37 (0x25)
.maxstack 3
.locals init (string V_0)
IL_0000: ldstr "({0}, {1}"
IL_0005: ldarg.0
IL_0006: ldfld int32 Point::x
IL_000b: box [mscorlib]System.Int32
IL_0010: ldarg.0
IL_0011: ldfld int32 Point::y
IL_0016: box [mscorlib]System.Int32
IL_001b: call string [mscorlib]System.String::Format(string,
object,
object)
IL_0020: stloc.0
IL_0021: br.s IL_0023
IL_0023: ldloc.0
IL_0024: ret
} // end of method Point::ToString
请各位高手指教。
转载于:https://www.cnblogs.com/gamix/archive/2005/04/12/136414.html