按时打算的撒

    public static class KZfun
    {
    ///
    /// 模拟Lamdan表达式
    ///
    /// 当前对象
    /// 泛型委托
    /// 结果集
    public static IEnumerable Where(this IEnumerable val, Func predicate)
    {
    var b1 = new Func(predicate);
     List temp = new List();
    foreach (var xx in val)
    {
    if (b1(xx))
    {
    temp.Add(xx);
    }
    }
    return temp;
    }
***
///
/// 重载
///
/// 类型
/// 当前对象
/// 结果集
public static IEnumerable Where(this IEnumerable val)
{
return val;
}
///
/// 返回和
///
/// 当前对象
/// 和
public static int? Sum(this IEnumerable val)
{
int? sum = 0;
foreach (var xx in val)
{
sum += xx;
}
return sum;
}
///
/// 返回最大值
///
/// 当前对象
/// 最大值
public static int Max(this IEnumerable val)
{
int max = 0;
foreach (var xx in val)
{
if (xx >= max)
{
max = xx;
}
}
return max;
}

///
/// 返回包含某个字符的字符串
///
/// 当前对象
/// 字符
/// 包含chars字符的字符串
public static List GetOneStr(this IEnumerable val, string chars)
{
List temp = new List();
foreach (var xx in val)
{
if (xx.Contains(chars))
{
temp.Add(xx);
}
}
return temp;
}
}

//调用
 static void Main(string[] args)
        {

            List test = new List { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
            int sum = test.Where(a => { return a > 3; }).Sum();
            int max = test.Where(a => { return a > 3; }).Max();
            Console.WriteLine(sum);
            Console.WriteLine(max);

            List Strs = new List() {"aaaa","abbb","caaaa","cccc","bbbbb"};
            Strs = Strs.Where().GetOneStr("a");
            foreach (var xx in Strs)
            {
                Console.WriteLine(xx);
            }
            Console.ReadKey();
        }