WPF.Net v4.7.2 令人担忧的调试和直接运行的区别

Question

I was using.Net 4.0 and now I have updated to.Net 4.7.2. I have noticed very worrying problems. The program now behaves differently when running from the Visual Studio (2012) debugger or running from the ex e directly.

These are two problems I have noticed that don't happen with the debugger but do happen when running from the exe :

1. A DataGrid column that had "*" to use the remaining width just shows the column the minimum width to hold the data.

2. Page Loaded events are only fired sometimes. This seems to be affected by the amount of working being done when displaying the page. Like if there is too much work it just does not bother firing the event.

Anyone else having this or know why?

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More info on this. I have discovered it is always firing the Page Loaded event but it was before I had subscribed to it.

So what this means is that in debug things are happening at a different speed to direct running causing things to happen in a different order - race condition.

Answer 1

They introduced a new allocation algorithm in 4.7 to prevent infinite loops that ocurred during the layout of a Grid under some circumstances. Please refer to the docs for more information.

You can disable the new algorithm by adding a switch to your App.config file:

<runtime>
  <AppContextSwitchOverrides value="Switch.System.Windows.Controls.Grid.StarDefinitionsCanExceedAvailableSpace=true" />
</runtime>