var  MainSkill =  string  .Join（ ，，SkillId.Where（x = >  x！ =  null &&！string.IsNullOrWhiteSpace（x.ToString（））））; 

只需使用LINQ并解决它

  //  首先删除空字符串 
 test = test.Where（x = &gt ; ！string.IsNullOrEmpty（SkillId））。ToArray（）; 
 //  现在连接它 
 var  MainSkill =  string  .Join（ ，，test）; 

i have an array i want to convert that array value to string ,when i am not inserting anything value its taking 1st value then comma then comma
i want to delete that comma


SkillId[0]=1
SkillId[2]=2
SkillId[3]=""
var MainSkill = string.Join(",", SkillId);
Tst.Skill = MainSkill;

here its coming "1,2,,"
how to delete the last cooma or add 0 there

var MainSkill = string.Join(",", SkillId.Where(x => x != null && !string.IsNullOrWhiteSpace(x.ToString())));

Just use LINQ and get it resolve

//first remove empty string
test =  test.Where(x => !string.IsNullOrEmpty(SkillId)).ToArray();
//now concatenate it
var MainSkill = string.Join(",", test);