防止ToString() 没值报错/TryGetValue

 

           Dictionary<string, object> keyValuePairs = new Dictionary<string, object>()
            {
                { "1","a"},
                { "2","b"},
             
            };

            var str = string.Empty;
            object ret;

            var end= keyValuePairs.TryGetValue("1", out ret);

            str= ret?.ToString();

            if (string.IsNullOrEmpty(str))
            { 
            
            }

 

            var str = string.Empty;
            object ret;
            var end = keyValuePairs.TryGetValue("1", out ret);
            str = ret?.ToString();

            if (string.IsNullOrEmpty(str))
            {
            }

            bool xs = "q".Equals("Q", StringComparison.OrdinalIgnoreCase);
            bool sx = "q".Equals("Q");

            string sd = null;
            var q = sd?.ToString();

            string sd2 = "";
            var q2 = sd?.ToString();


            int? xx = null;
            int? intCanNull = null;
            var hasValues = intCanNull.HasValue;
            if (hasValues)
            {
                int num = intCanNull.GetValueOrDefault();
            }
            else
            {
                int num = intCanNull.GetValueOrDefault();
            }