string.join加引号

columnsGen = string.Join(",", modelDictionary.Keys);
valueGen = modelDictionary.Values.Aggregate(valueGen, (current, i) => current + ("'" + i + "',")).Trim(',');

var cparr = checkPoint.Split(',');
string tempcheckPoint = string.Empty;
tempcheckPoint = cparr.Aggregate("", (current, i) => current + ("'" + i + "',")).Trim(',');