dotnet/Documentation/compatibility/wpf-hang-when-resizing-a-grid.md

## Resizing a Grid can hang

### Scope
Edge

### Version Introduced
4.7

### Version Reverted
4.7.1

### Source Analyzer Status
NotPlanned

### Change Description
An infinite loop can occur during layout of a `T:System.Windows.Controls.Grid` under the following
circumstances:

* Row definitions contain two *-rows, both declaring a MinHeight and a MaxHeight.
* Content of the *-rows doesn't exceed the corresponding MaxHeight
* The Grid's available height is exceeded by the first MinHeight (plus any other fixed or Auto rows)
* The app targets .NET Framework 4.7, or opts in to the 4.7 allocation algorithm by setting
   `Switch.System.Windows.Controls.Grid.StarDefinitionsCanExceedAvailableSpace=false`

The loop would also happen with more than two rows, or in the analogous case for columns.

The issue is fixed in .NET Framework 4.7.1.

- [ ] Quirked
- [ ] Build-time break

### Recommended Action
Upgrade to .NET Framework 4.7.1.  Alternatively, if you don't need the 4.7 allocation algorithm
you can use the following configuration setting:

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

### Affected APIs
 * Not detectable via API analysis

### Category
Windows Presentation Foundation (WPF)

<!--
    ### Original Bug
    442027
-->