// Search for a friend by keyword
FriendSearchParam param = new FriendSearchParam
{
  friendship_search_param_keyword_list = new List<string>
  {
    "Keyword 1"
  },
  friendship_search_param_search_field_list = new List<TIMFriendshipSearchFieldKey>
  {
    TIMFriendshipSearchFieldKey.kTIMFriendshipSearchFieldKey_Identifier,
    TIMFriendshipSearchFieldKey.kTIMFriendshipSearchFieldKey_NikeName,
    TIMFriendshipSearchFieldKey.kTIMFriendshipSearchFieldKey_Remark
  }
};
TIMResult res = TencentIMSDK.MsgSearchLocalMessages(param, (int code, string desc, List<FriendInfoGetResult> result, string user_data)=>{
 // Process the async logic
});