.NET常用功能

1.判断对象判不为null或不为""或不为"undefined"

public static bool isNotNullOrBlank(Object obj)
{
    if (obj == null || obj.ToString().Trim() == "" || obj.ToString() == "undefined" || obj.ToString().Equals(decimal.MinValue.ToString()))
        return false;
    else
        return true;
} 

2.将对象转换为decimal数字,取N位小数点

decimal.Round(Convert.ToDecimal(dt.Rows[i]["str"]), n).ToString(); 

3.Tool工具包会自动将,分割为sql，eg:100,101分割为('100','101')，需要用Match判断然后替换成(100,101)

//v.getCondition()为分割补充查询条件
string Condition = v.getCondition();
//ExtJs:S_SEC_ID.getValue() != "" ?  S_SEC_ID.getValue() + "&'" : S_SEC_ID.getValue()  //前端增加&用来判断是此字段  //toUpperCase()可以变为大写
//用正则获取DRAW.customer_col_3的对应值
string result = System.Text.RegularExpressions.Regex.Match(Condition, "(?<=DRAW.customer_col_3 like).*?(?=&'')").Value;  //值为空时不给判断符号  
//s = Regex.Replace(s, @"\r\n", " ");  //\r\n是转行
if (result != "")//result存在时
{
    string result2 = " '" + result.Replace("'", "").Replace(" ","");
    Condition = Condition.Replace(result, result2).Replace("&'", "");  //替换原字符串
}

 4.创建字典，添加字典key,value

Dictionary<string, string> dictionary= new Dictionary<string, string>();
//添加
dictionary.Add("key", "value");
//根据key获取value
string key=dictionary["key"]
//根据value获取key //Linq
string value=dictionary.First(kv => kv.Value == "value").Key;

5.创建泛型集合，添加元素，转成数组

List<string> NameList = new List<string>();
NameList.Add("value");
string[] NameArray = NameList.ToArray();