请问,我定义一个类,然后定义一个实体类的列表,执行 testList.Add(test);这句的时候总是报错,代码如下:
public class TEST
{
public int ScheduleID
{
get
{
return scheduleID;
} set
{
scheduleID = value;
}
} public string CreateUser
{
get
{
return createUser;
} set
{
createUser = value;
}
} private int scheduleID;
private string createUser;
}IList<TEST> testList = null;
TEST test = new TEST();
test.ScheduleID = 124856;
test.CreateUser = "user";
testList.Add(test);
public class TEST
{
public int ScheduleID
{
get
{
return scheduleID;
} set
{
scheduleID = value;
}
} public string CreateUser
{
get
{
return createUser;
} set
{
createUser = value;
}
} private int scheduleID;
private string createUser;
}IList<TEST> testList = null;
TEST test = new TEST();
test.ScheduleID = 124856;
test.CreateUser = "user";
testList.Add(test);
你的 testList = null?你用它add肯定会报空引用 ,先实例化一个IList<TEST>
using System;
using System.Collections;
using System.Collections.Generic; public class MyClass
{
public static void Main()
{
List<int> iList = new List<int>();
int[] iArray = new int[0];
ArrayList al = new ArrayList();
int count = 10;
//==========================
//增加元素
//==========================
for(int i = 0; i < count; ++i)
{
iList.Add(i);
} iArray = new int[count];//需要初始化
for(int i = 0; i < count; ++i)
{
iArray[i] = i;
} for(int i = 0; i < count; ++i)
{
al.Add(i);//这里有box操作
}
//==========================
//输出
//==========================
foreach(int i in iList)
{
Console.WriteLine(i);
} foreach(int i in iArray)
{
Console.WriteLine(i);
} foreach(object o in al)
{
Console.WriteLine(o);//这里有unbox操作
}
//============================
//继续增加元素
//============================
iList.Add(count); iArray = new int[count+1];//需要重新分配内存
for(int i = 0; i < count; ++i)
{
iArray[i] = i;
}
iArray[count] = count; al.Add(count); } }
List<TEST> testList = new List<TEST>();
然后就可以了!