我正在尝试使用反射从动态类中检索字段或属性,但当我使用Getfield或GetProperty调用动态对象时,它无法找到该字段,并且没有进入任何动态对象的Try*方法。
不确定为什么在.net4上无法正常工作。
请参见下面的testdyn动态测试类。
我是这样调用它的:
获取这些结果:
预计会看到:
不确定为什么在.net4上无法正常工作。
请参见下面的testdyn动态测试类。
我是这样调用它的:
dynamic td = new testdyn();
td.SendDebugEvent += new DebugDelegate(debug);
td.test();
获取这些结果:
one = -1
two = -1
fiddle = -1
test = -1
set: fiddle = 241827974
fiddle = -1
预计会看到:
one = 1
two = 2
fiddle = 3
test = -1
set: fiddle = 241827974
fiddle = 241827974
我做错了什么?
注意:如果我调用'td.fiddle',它确实可以正常工作...但是你会知道创建类的名称却不知道访问它的名称似乎很奇怪??
从这篇文章中可以看出,也许Reflection不支持DynamicObject,因为它实现了IDynamicMetaObjectProvider。
问题在于这段代码被外部应用程序使用了反射。
如果你有想法,请告诉我。
代码如下。
public delegate void DebugDelegate(string msg);
public class testdyn : System.Dynamic.DynamicObject
{
List<string> items = new List<string>(new string[] { "one", "two", "fiddle", "my", "lou" });
List<int> vals = new List<int>( new int[] { 1,2,3,5,8 });
public event DebugDelegate SendDebugEvent;
void debug(string msg)
{
if (SendDebugEvent!=null)
SendDebugEvent(msg);
}
public void set(string name, int v)
{
var idx = items.IndexOf(name);
if (idx < 0)
return;
vals[idx] = v;
debug("set: " + name + " = " + v);
}
int get(string name)
{
object o = null;
var t = GetType();
try {
o = t.GetProperty(name).GetValue(this, null);
int v = (int)o;
return v;
} catch
{
try
{
var f = t.GetField(name);
o = f.GetValue(this);
return (int)o;
}
catch
{
}
}
return -1;
}
string g(string name) { return name+" = "+get(name).ToString(); }
Random r = new Random();
public void test() { test(string.Empty); }
public void test(string mytmp)
{
var t = GetType();
// do some reads
debug(g("one"));
debug(g("two"));
debug(g("fiddle"));
debug(g("test"));
// do some sets
set("fiddle", r.Next());
// they should change
debug(g("fiddle"));
}
public override bool TryInvokeMember(System.Dynamic.InvokeMemberBinder binder, object[] args, out object result)
{
debug("got invoke member");
return base.TryInvokeMember(binder, args, out result);
}
public override bool TrySetMember(System.Dynamic.SetMemberBinder binder, object value)
{
debug("got setmember");
return base.TrySetMember(binder, value);
}
public override bool TryGetIndex(System.Dynamic.GetIndexBinder binder, object[] indexes, out object result)
{
debug("got getindex");
return base.TryGetIndex(binder, indexes, out result);
}
public override bool TryGetMember(System.Dynamic.GetMemberBinder binder, out object result)
{
// get index of column value trying to be retrieved
var idx = items.IndexOf(binder.Name);
// default to empty
result = string.Empty;
// return error if we can't find
if (idx < 0)
{
return base.TryGetMember(binder, out result);
}
// get result
result = vals[idx];
return true;
}
public override bool TryInvoke(System.Dynamic.InvokeBinder binder, object[] args, out object result)
{
debug("got invoke");
return base.TryInvoke(binder, args, out result);
}
public override bool TryCreateInstance(System.Dynamic.CreateInstanceBinder binder, object[] args, out object result)
{
debug("got create instance");
return base.TryCreateInstance(binder, args, out result);
}
public override IEnumerable<string> GetDynamicMemberNames()
{
debug("got member names");
return items.ToArray();
}
}