C# string类Remove函数未生效

维护如下代码的时候发现经过Remove动作后PassItems和ProblemError变量仍然以逗号（","）结尾，及Remove函数未生效。

if ((Application.Current as App).PassItems.EndsWith(","))
                    (Application.Current as App).PassItems.Remove((Application.Current as App).PassItems.Length - 1);

if ((Application.Current as App).ProblemError.EndsWith(","))
                    (Application.Current as App).ProblemError.Remove((Application.Current as App).ProblemError.Length - 1);

查询资料发现C#中的string类的Remove函数只是生成了一个新的字符串，如果要在原始字符串中移除一部分数据，则需要将新生成的字符串重新赋值给原始变量，如：

if ((Application.Current as App).PassItems.EndsWith(","))
                    (Application.Current as App).PassItems = (Application.Current as App).PassItems.Remove((Application.Current as App).PassItems.Length - 1);

if ((Application.Current as App).ProblemError.EndsWith(","))
                    (Application.Current as App).ProblemError = (Application.Current as App).ProblemError.Remove((Application.Current as App).ProblemError.Length - 1);

按照如上改动后变量PassItems和ProblemError最后结尾处的（","）将会被移除。