protected override List <object> _Filter(List <object> _unfilteredData, string _displayMember, string userInput) { int count = userInput.Length - 1; string userLetters = userInput.ToLower(); List <object> results = new List <object>(); foreach (var obj in _unfilteredData) { var itemLetters = GetFilterString(obj, _displayMember).ToLower(); if (count < itemLetters.Length) { char currentLetter = itemLetters[count]; // 如果是英文 if (CharUtil.IsEnglishLetter(currentLetter)) { if (currentLetter.ToString().ToLower()[0] == userLetters[count]) { results.Add(obj); } continue; } } } return(results); }