Add and remove User into SharePoint group Using Client Object Model

ClientContext client = new ClientContext(“http://SiteUrl”);

client.ExecuteQuery();

Web website = client.Web;

client.Load(website, w => w.AllProperties, w => w.SiteGroups, w => w.SiteUserInfoList, w => w.Webs,w => w.Title);

client.ExecuteQuery();

GroupCollection groupCollection = website.SiteGroups;

client.Load(groupCollection, groups => groups.Include(grps => grps.Users, grps => grps.Title));

client.ExecuteQuery();

User user;

foreach (Group group in groupCollection)

{

if (group.Title.Equals(“GroupName”))

{

UserCreationInformation userInfo = new UserCreationInformation();

userInfo.LoginName = “UserName”;

if (“Add”)

{

user = group.Users.Add(userInfo);

group.Users.AddUser(user);

}

else if (“Remove”)

{

user = group.Users.GetByLoginName(“UserName”);

group.Users.Remove(user);

}

group.Update();

website.Update();

client.ExecuteQuery();

}

}