c#泛型TryParse类型转换

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Reflection;
using System.Data;namespace ConsoleApplication11
{
class Program
{
static void Main(string[] args)
{
var dt = new DataTable();
dt.Columns.Add("c1", typeof(string));
var row = dt.NewRow();
row["c1"] = "abc";
var c = getDataFromDBField<double>(row["c1"], ); //返回2
var d = getDataFromDBField<object>(row["c1"], ); //返回"abc"
} private static T getDataFromDBField<T>(object obj, T defaultValue = default(T))
{
if (obj == null || obj == DBNull.Value)
return defaultValue; Type t = typeof(T);
if (t.IsGenericType && t.GetGenericTypeDefinition() == typeof(Nullable<>)) //支持可空类型
   t = t.GetGenericArguments()[0];
var tryParse = t.GetMethod("TryParse", BindingFlags.Public | BindingFlags.Static, Type.DefaultBinder
, new Type[] { obj.GetType() , t.MakeByRefType() }
, new ParameterModifier[] { new ParameterModifier() }); if (tryParse != null)
{
var parameters = new object[] { obj, Activator.CreateInstance(t) };
bool success = (bool)tryParse.Invoke(null, parameters);
if (success)
return (T)parameters[];
else
return defaultValue;
} return (T)Convert.ChangeType(obj, typeof(T));
}
}
}