如题 如何获取这个List里面的值。前提是我不知道这个List里面是什么类型我把一个List<MyEntity> 作为一个Object对象传到一个方法里了，那这个方法怎么获取List里面的值呢？
List<MyEntity> a = new List<MyEntity>();
a.Add(obj);
MyFun(a);public void MyFun(Object obj){
//如何获取这个List里面的值。前提是我不知道这个List里面是什么类型
}
List<MyEntity> a = new List<MyEntity>();
a.Add(obj);
MyFun(a);public void MyFun(Object obj){
//如何获取这个List里面的值。前提是我不知道这个List里面是什么类型
}
public void MyFun(List <MyEntity> obj){
//如何获取这个List里面的值。前提是我不知道这个List里面是什么类型
}，如果你一定要装箱的话，看看能不能进行数据转换了：
public void MyFun(Object obj){
//如何获取这个List里面的值。前提是我不知道这个List里面是什么类型
List<MyEntity> listObj=(List<MyEntity>)obj;
}
恩，程序的需要，所以要装箱，至于转换，是转换不了的，因为我不知道具体这个类型是什么类型。我很想把这个Object类型转换成List<Object>，这样，我就可以用反射把他的属性值都取出来，但我实在不知道怎么转换。或者说用别的方法？
不好意思，其实我具体的东西没写太多，害怕把大家绕进去了。是这样的我用一个方法，去获取这个对象里面的属性值public bool AuditDeleteObject(Object obj, String userName)
{
PropertyInfo[] pis = obj.GetType().GetProperties(BindingFlags.Public | BindingFlags.Instance);//获得对象的所有public属性
Dictionary<string, PropertyInfo> DCPropertyInfo = new Dictionary<string, PropertyInfo>();
foreach (PropertyInfo pi in pis)
{
if (pi.PropertyType.Name.ToString()=="List`1")
{//如果这个对象的属性是个List集合
if (pi.GetValue(obj, null) != null)
{
AuditDeleteObject(pi.GetValue(obj, null), userName);
//本来想递归调用去继续解析这个属性对象，但传过去的list,就不会了
}
}
else
{
DCPropertyInfo.Add(pi.Name.ToUpper(), pi);
} }
return true;
}
// Code for building SimpleType.dll.
using System;namespace Simple_Type
{
public class MySimpleClass
{
public void MyMethod(string str, int i)
{
Console.WriteLine("MyMethod parameters: {0}, {1}", str, i);
} public void MyMethod(string str, int i, int j)
{
Console.WriteLine("MyMethod parameters: {0}, {1}, {2}",
str, i, j);
}
}
}
using System;
using System.Reflection;
using System.Globalization;
using Simple_Type;
namespace Custom_Binder
{
class MyMainClass
{
static void Main()
{
// Get the type of MySimpleClass.
Type myType = typeof(MySimpleClass); // Get an instance of MySimpleClass.
MySimpleClass myInstance = new MySimpleClass();
MyCustomBinder myCustomBinder = new MyCustomBinder(); // Get the method information for the particular overload
// being sought.
MethodInfo myMethod = myType.GetMethod("MyMethod",
BindingFlags.Public | BindingFlags.Instance,
myCustomBinder, new Type[] {typeof(string),
typeof(int)}, null);
Console.WriteLine(myMethod.ToString());
// Invoke the overload.
myType.InvokeMember("MyMethod", BindingFlags.InvokeMethod,
myCustomBinder, myInstance,
new Object[] {"Testing...", (int)32});
}
} //****************************************************
// A simple custom binder that provides no
// argument type conversion.
//****************************************************
class MyCustomBinder : Binder
{
public override MethodBase BindToMethod(
BindingFlags bindingAttr,
MethodBase[] match,
ref object[] args,
ParameterModifier[] modifiers,
CultureInfo culture,
string[] names,
out object state)
{
if(match == null)
throw new ArgumentNullException("match");
// Arguments are not being reordered.
state = null;
// Find a parameter match and return the first method with
// parameters that match the request.
foreach(MethodBase mb in match)
{
ParameterInfo[] parameters = mb.GetParameters(); if(ParametersMatch(parameters, args))
return mb;
}
return null;
} public override FieldInfo BindToField(BindingFlags bindingAttr,
FieldInfo[] match, object value, CultureInfo culture)
{
if(match == null)
throw new ArgumentNullException("match");
foreach(FieldInfo fi in match)
{
if(fi.GetType() == value.GetType())
return fi;
}
return null;
} public override MethodBase SelectMethod(
BindingFlags bindingAttr,
MethodBase[] match,
Type[] types,
ParameterModifier[] modifiers)
{
if(match == null)
throw new ArgumentNullException("match"); // Find a parameter match and return the first method with
// parameters that match the request.
foreach(MethodBase mb in match)
{
ParameterInfo[] parameters = mb.GetParameters();
if(ParametersMatch(parameters, types))
return mb;
} return null;
} public override PropertyInfo SelectProperty(
BindingFlags bindingAttr,
PropertyInfo[] match,
Type returnType,
Type[] indexes,
ParameterModifier[] modifiers)
{
if(match == null)
throw new ArgumentNullException("match");
foreach(PropertyInfo pi in match)
{
if(pi.GetType() == returnType &&
ParametersMatch(pi.GetIndexParameters(), indexes))
return pi;
}
return null;
} public override object ChangeType(
object value,
Type myChangeType,
CultureInfo culture)
{
try
{
object newType;
newType = Convert.ChangeType(value, myChangeType);
return newType;
}
// Throw an InvalidCastException if the conversion cannot
// be done by the Convert.ChangeType method.
catch(InvalidCastException)
{
return null;
}
} public override void ReorderArgumentArray(ref object[] args,
object state)
{
// No operation is needed here because BindToMethod does not
// reorder the args array. The most common implementation
// of this method is shown below.
// ((BinderState)state).args.CopyTo(args, 0);
} // Returns true only if the type of each object in a matches
// the type of each corresponding object in b.
private bool ParametersMatch(ParameterInfo[] a, object[] b)
{
if(a.Length != b.Length)
return false;
for(int i = 0; i < a.Length; i++)
{
if(a[i].ParameterType != b[i].GetType())
return false;
}
return true;
} // Returns true only if the type of each object in a matches
// the type of each corresponding entry in b.
private bool ParametersMatch(ParameterInfo[] a, Type[] b)
{
if(a.Length != b.Length)
return false;
for(int i = 0; i < a.Length; i++)
{
if(a[i].ParameterType != b[i])
return false;
}
return true;
}
}
}
问题是，我不知道List 里面是什么类型的东西，所以我不能这样来转换，如果知道就简单了 :(
{
List<int> list = new List<int>();
list.Add(1); Object o = list; List<int> anotherList = (List<int>)o;
for (int i = 0; i < anotherList.Count; i++)
{
Console.WriteLine(anotherList[i]);
} Console.ReadLine();
}
我发现这两者之间是可以进行转换的！
用List<Object> lobj =Obj as List<Object>;
lobj对象始终为null
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Reflection;namespace WindowsApplication276
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent(); List<String> a = new List<String>();
a.Add("A");
MyFun(a);
} public void MyFun(Object obj)
{
Type T = obj.GetType(); if (T.GetInterface("IList") != null && T.IsGenericType)
{
String FullTypeString = T.FullName;
FullTypeString = FullTypeString.Remove(0, FullTypeString.IndexOf("[[") + 2); String SubItemTypeString = FullTypeString.Substring(0, FullTypeString.IndexOf(',')); if (Type.GetType(SubItemTypeString) == typeof(String))
{
List<String> L = (List<String>)obj;
MessageBox.Show(L[0]);
}
}
}
}
}
不过还是谢谢以上回答的朋友们，给了我很多提示
用这个方法可以解决掉，转换为数组。以下是关键代码if (pi.PropertyType.IsGenericType && pi.PropertyType.GetInterface("IList")!=null)
{
Object ListO = pi.GetValue(obj, null);
if (ListO != null)
{
MethodInfo method = ListO.GetType().GetMethod("ToArray");
AuditDeleteObjects(method.Invoke(ListO, null), userName);
}
}如果是List 就调用它自己的ToArray方法public bool AuditDeleteObjects(Object obj, String userName)
{
Object[] objs;
if (obj.GetType().IsArray && obj.GetType().BaseType.FullName == "System.Array")
{
objs = obj as Object[];
}
else {
objs =new Object[] {obj};
}
.......
}
a.Add(obj);
MyFun(a);public void MyFun<T>(List<T> t){
//如何获取这个List里面的值。前提是我不知道这个List里面是什么类型
t.foreach(x=>{
var yy=x.xxx...
...
});
}