在SectionsCollection中清除LiveCharts中的WPF

Question

我正在用面向对象的LiveCharts构建一个WPF数据可视化工具。我有一个名为SectionsCollection的SectionsCollection对象，需要在数据变化时重新加载它。在重新分配到SectionsCollection之前，我运行以下代码段。

        try
        {
            if (SectionsCollection != null && SectionsCollection.Count > 0)
            {
                SectionsCollection.Clear();
            }
        }
        catch(Exception e)
        {
            Status += "Error in clearing SectionsCollection.\n"+e;
        }
        SectionsCollection = new SectionsCollection();

以下错误在SectionsCollection.Clear();行上间歇性地发生，标签NullReferenceException发生。

Exception thrown: 'System.NullReferenceException' in LiveCharts.Wpf.dll

Additional information: Object reference not set to an instance of an object.

如果我检查SectionsCollection不是空的，也不是空的，为什么会出现这个错误？

对于VisualsCollection和SeriesCollection类型，似乎也会出现此错误。

Answer 1

尝试添加标志以防止不必要的多个exec。在你的过程中：

 bool collIsBusy = false;
        try
        {
            if (SectionsCollection != null && SectionsCollection.Count > 0 && !collIsBusy)
            {
                collIsBusy = true; //flag to prevent throttling multiple executions
                SectionsCollection.Clear();
                collIsBusy = false;
            }
        }
        catch (Exception e)
        {
            Status += "Error in clearing SectionsCollection.\n" + e;
        }
        SectionsCollection = new SectionsCollection();