https://blog.youkuaiyun.com/daonezh-cnhttps://blog.youkuaiyun.com/https://blog.youkuaiyun.com/daone/article/details/42488685https://blog.youkuaiyun.com/daone/article/details/42488685daoneWed, 07 Jan 2015 10:43:31 +0800 { /// Console.WriteLine("{0}{]]>https://blog.youkuaiyun.com/daone/article/details/42488565https://blog.youkuaiyun.com/daone/article/details/42488565daoneWed, 07 Jan 2015 10:33:42 +0800https://blog.youkuaiyun.com/daone/article/details/42488481https://blog.youkuaiyun.com/daone/article/details/42488481daoneWed, 07 Jan 2015 10:29:45 +0800https://blog.youkuaiyun.com/daone/article/details/42488311https://blog.youkuaiyun.com/daone/article/details/42488311daoneWed, 07 Jan 2015 10:27:27 +0800https://blog.youkuaiyun.com/daone/article/details/42488039https://blog.youkuaiyun.com/daone/article/details/42488039daoneWed, 07 Jan 2015 10:21:41 +0800https://blog.youkuaiyun.com/daone/article/details/42487949https://blog.youkuaiyun.com/daone/article/details/42487949daoneWed, 07 Jan 2015 10:16:23 +0800https://blog.youkuaiyun.com/daone/article/details/42487655https://blog.youkuaiyun.com/daone/article/details/42487655daoneWed, 07 Jan 2015 10:05:41 +0800https://blog.youkuaiyun.com/daone/article/details/29872907https://blog.youkuaiyun.com/daone/article/details/29872907daoneTue, 10 Jun 2014 18:44:47 +0800https://blog.youkuaiyun.com/daone/article/details/18219569https://blog.youkuaiyun.com/daone/article/details/18219569daoneMon, 13 Jan 2014 13:36:58 +0800https://blog.youkuaiyun.com/daone/article/details/18219425https://blog.youkuaiyun.com/daone/article/details/18219425daoneMon, 13 Jan 2014 13:30:21 +0800https://blog.youkuaiyun.com/daone/article/details/18032737https://blog.youkuaiyun.com/daone/article/details/18032737daoneThu, 09 Jan 2014 08:42:47 +0800https://blog.youkuaiyun.com/daone/article/details/18032665https://blog.youkuaiyun.com/daone/article/details/18032665daoneThu, 09 Jan 2014 08:38:22 +0800https://blog.youkuaiyun.com/daone/article/details/18032365https://blog.youkuaiyun.com/daone/article/details/18032365daoneThu, 09 Jan 2014 08:28:31 +0800https://blog.youkuaiyun.com/daone/article/details/6872931https://blog.youkuaiyun.com/daone/article/details/6872931daoneFri, 14 Oct 2011 11:42:33 +0800 是 lamada 运算符，可读为“goes to” 输入一个表示整型的字符串列表，并返回一个列表，包含其中偶数的平方，并且需要按照平方后的结果排序”。 原: static List GetSquaresOfPositive(List strList)]]>https://blog.youkuaiyun.com/daone/article/details/6834354https://blog.youkuaiyun.com/daone/article/details/6834354daoneThu, 29 Sep 2011 16:20:52 +0800https://blog.youkuaiyun.com/daone/article/details/6316132https://blog.youkuaiyun.com/daone/article/details/6316132daoneMon, 11 Apr 2011 17:29:00 +0800https://blog.youkuaiyun.com/daone/article/details/6316126https://blog.youkuaiyun.com/daone/article/details/6316126daoneMon, 11 Apr 2011 17:28:00 +0800关于类型的判断和转换有is和as这2个操作符。
具体区别和用法如下
is就是处于对类型的判断。返回true和false。如果一个对象是某个类型或是其父类型的话就返回为true，否则的话就会返回为false。另外is操作符永远不会抛出异常。代码如下：
System.Boolean b1 = (o is System.Object);//b1 为true
System.Boolean b2 = (o is Employee);//b2为false
如]]>https://blog.youkuaiyun.com/daone/article/details/6316115https://blog.youkuaiyun.com/daone/article/details/6316115daoneMon, 11 Apr 2011 17:25:00 +0800问号:
单问号---用于给变量设初值的时候,给变量(int类型)赋值为null,而不是0!
双问号---用于判断并赋值,先判断当前变量是否为null,如果是就可以赋一个新值,否则跳过!
 
（1）DbCommand.ExecuteScalar方法执行时，如果没有满足条件的数据，会返回null还是DbNull.Value？
答案：返回DBNull.Value
（2）使用Convert.ToString()方法将null或者DBNull.V]]>https://blog.youkuaiyun.com/daone/article/details/6316093https://blog.youkuaiyun.com/daone/article/details/6316093daoneMon, 11 Apr 2011 17:20:00 +08001.自定义一个透视表的结构体
public struct PivotItem { public string ascID; public object smTatY; public object smTatN; public object sxTatY; public object sxTatN; }
 

2.方法
using Ex]]>https://blog.youkuaiyun.com/daone/article/details/6316070https://blog.youkuaiyun.com/daone/article/details/6316070daoneMon, 11 Apr 2011 17:13:00 +0800一、数组
C#使用List,
内部实现都是数组,也就是一块连续的内存区域,插入、删除操作慢,随机访问速度快。
如:List list = new List();
二、链表
C#使用LinkedList,内部实现都是链表,插入、删除速度快,随机访问速度慢。
如:LinkedList link = new LinkedList();
三、字典
C]]>