c# - LINQ 查询中的三元运算符未按预期工作

Question

我正在尝试根据某些条件过滤对象列表。我看到一些帖子在他们的 LINQ 查询中使用三元运算符来完成此任务。

此代码片段的底部是我的 LINQ 查询。我希望它测试每个 where，而它似乎只尝试第一个 where 并留下其余部分。 List 不包含我期望的数据。我做错了什么？

    private ObservableCollection<LogEvent> m_LogEvents = ApplicationData.MainLogEntries.LogEvents;
    public ObservableCollection<LogEvent> LogEvents
    {
        get { return m_LogEvents; }
        set { m_LogEvents = value; RaisePropertyChanged("LogEvents"); }
    }

    private bool m_ViewDebugLogs = false;
    public bool ViewDebugLogs
    {
        get { return m_ViewDebugLogs; }
        set { m_ViewDebugLogs = value; RaisePropertyChanged("ViewDebugLogs"); FilterList(); }
    }

    private bool m_ViewErrorLogs = true;
    public bool ViewErrorLogs
    {
        get { return m_ViewErrorLogs; }
        set { m_ViewErrorLogs = value; RaisePropertyChanged("ViewErrorLogs"); FilterList(); }
    }

    private bool m_ViewInfoLogs = true;
    public bool ViewInfoLogs
    {
        get { return m_ViewInfoLogs; }
        set { m_ViewInfoLogs = value; RaisePropertyChanged("ViewInfoLogs"); FilterList(); }
    }

    private void FilterList()
    {
        List<LogEvent> selectedEvents = (from x in LogEvents
                                         where (ViewDebugLogs) ? x.Level == "Debug" : false
                                         where (ViewErrorLogs) ? x.Level == "Error" : false
                                         where (ViewInfoLogs) ? x.Level == "Info" : false
                                         select x).ToList();

    }

编辑:此操作的目标是启用适当的 bool ViewDebugLogs、ViewErrorLogs 或 ViewInfoLogs 或三者的任意组合日志按适当的类型过滤。

我已经从答案中尝试了以下但没有成功:

这只获取调试日志:

            List<LogEvent> selectedEvents = (from x in LogEvents
                                         where (ViewDebugLogs == true) ? x.Level == "Debug" : false
                                         || (ViewErrorLogs == true) ? x.Level == "Error" : false
                                         || (ViewInfoLogs == true) ? x.Level == "Info" : false
                                         select x).ToList();

这只获取调试日志:

            List<LogEvent> selectedEvents = (from x in LogEvents
                                         where (ViewDebugLogs == true) ? x.Level == "Debug" : true
                                         || (ViewErrorLogs == true) ? x.Level == "Error" : true
                                         || (ViewInfoLogs == true) ? x.Level == "Info" : true
                                         select x).ToList();

这什么也得不到:

            List<LogEvent> selectedEvents = (from x in LogEvents
                                         where (ViewDebugLogs == true) ? x.Level == "Debug" : true
                                         where (ViewErrorLogs == true) ? x.Level == "Error" : true
                                         where (ViewInfoLogs == true) ? x.Level == "Info" : true
                                         select x).ToList();

Answer 1

多个 where 条件连接在一起，就像您使用 AND 一样。如果您尝试执行 OR，则应改用 ||。

List<LogEvent> selectedEvents = (from x in LogEvents
                                 where (ViewDebugLogs) ? x.Level == "Debug" : false
                                 || (ViewErrorLogs) ? x.Level == "Error" : false
                                 || (ViewInfoLogs) ? x.Level == "Info" : false
                                 select x).ToList();