C#(4.0)不常见的语法

:指定参数

public datatable todaytotable(int userid)
{
return userid > 0 ? v_cn_task_valid_scoring_today.querytable(condition: " where 承接者id = " + userid) : null;
}

其中的condition: " where 承接者id = " + userid就是指定参数 condition是querytable方法的参数

/// <summary>
/// 查询指定表的记录
/// </summary>
/// <param name="table">表名</param>
/// <param name="fields">select 子句的字段名列表</param>
/// <param name="condition">查询条件</param>
/// <param name="args">以半角逗号分隔的命令参数名称列表</param>
/// <param name="vals">命令参数值数组(可选)</param>
/// <returns>查询结果</returns>
public static datatable querytable(this string table, string fields = null, int? limit = null, string condition = null, string args = null, params object[] vals)
{
return gettable(table.querydataset(fields, limit, condition, args, vals), 0);
}

??运算符

var m_queryfields = fields.trimnull() ?? "*";

等于

var m_queryfields = fields.trimnull() ? "*"：fields.trimnull();