代码调用
代码如下:
namespace test
{
class Program
{
static void Main(string[] args)
{
var zoo1 = new zoo();
zoo1.animals = new List();
zoo1.animals.Add(new cat() { Name = "hello kitty", legs = 4 });
zoo1.animals.Add(new dog() { Name = "dog1", tail = true });
string json= fastJSON.JSON.Instance.ToJSON(zoo1); //序列化
var z = fastJSON.JSON.Instance.ToObject(json); //反序列化
Console.WriteLine(z.animals[0].Name);
Console.Read();
}
}
public class animal { public string Name { get; set; } }
public class cat : animal { public int legs { get; set; } }
public class dog : animal { public bool tail { get; set; } }
public class zoo { public List animals { get; set; }
}
基本的调用就是这么简单! 需要注意的是要反序列化的类好像必须声明为public的。
快速的秘密
大体浏览了一下代码，发现之所以快速的原因是作者利用反射时Emit了大量的IL代码：
代码如下:
internal object FastCreateInstance(Type objtype)
{
try
{
CreateObject c = null;
if (_constrcache.TryGetValue(objtype, out c))
{
return c();
}
else
{
if (objtype.IsClass)
{
DynamicMethod dynMethod = new DynamicMethod("_", objtype, null);
ILGenerator ilGen = dynMethod.GetILGenerator();
ilGen.Emit(OpCodes.Newobj, objtype.GetConstructor(Type.EmptyTypes));
ilGen.Emit(OpCodes.Ret);
c = (CreateObject)dynMethod.CreateDelegate(typeof(CreateObject));
_constrcache.Add(objtype, c);
}
else // structs
{
DynamicMethod dynMethod = new DynamicMethod("_",
MethodAttributes.Public | MethodAttributes.Static,
CallingConventions.Standard,
typeof(object),
null,
objtype, false);
ILGenerator ilGen = dynMethod.GetILGenerator();
var lv = ilGen.DeclareLocal(objtype);
ilGen.Emit(OpCodes.Ldloca_S, lv);
ilGen.Emit(OpCodes.Initobj, objtype);
ilGen.Emit(OpCodes.Ldloc_0);
ilGen.Emit(OpCodes.Box, objtype);
ilGen.Emit(OpCodes.Ret);
c = (CreateObject)dynMethod.CreateDelegate(typeof(CreateObject));
_constrcache.Add(objtype, c);
}
return c();
}
}
catch (Exception exc)
{
throw new Exception(string.Format("Failed to fast create instance for type '{0}' from assemebly '{1}'",
objtype.FullName, objtype.AssemblyQualifiedName), exc);
}
}