How to format a string of amounts in C #

<summary>///to convert amount to custom type string///</summary>///<param name= "precision" > required precision based on precision </par am>///<param name= "Money" > Need to convert amount </param>///<returns> converted amount </returns> public string formatestring (int precision, double) {//For example, Formatestring (2,2333) ==> result: 2,333.00 string format = "# #  
    #,###,###,# #0. ";  
    for (int i = 0; i < precision i++) {format = format + ' 0 '; Return money.  
ToString (format);  
///<summary>///Convert objects of any type to double///</summary>///<param name= "Val" > objects to be converted </param>  <returns> return variable of type double </returns> public double convertdouble (object val) {if ((val = null) || (Val. ToString () = "")) | |  
    (Val is DBNull))  
    {return 0.0; } if (Val is string) {val = val. ToString ().  
    Replace (",", "");  
    try {return convert.todouble (val); } 
    catch {return 0.0; }  
}

This paper url:http://www.bianceng.cn/programming/csharp/201410/45582.htm