dotnet upgrade

DotNetSolutionTools.App/Views/MainWindow.axaml

@@ -95,6 +95,15 @@
                         Clear bin and obj folders
                     </TextBlock>
                 </Button>
+                <Button Grid.Row="2" Grid.Column="1" MinHeight="130" Padding="10" Margin="5"
+                        HorizontalAlignment="Stretch" VerticalAlignment="Stretch"
+                        VerticalContentAlignment="Center" HorizontalContentAlignment="Center"
+                        IsEnabled="{Binding SolutionFilePath, Mode=OneWay, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"
+                        Command="{Binding UpdateAllProjectsToNet80Command}">
+                    <TextBlock TextWrapping="Wrap">
+                        Update all projects in Solution to .NET 8.0
+                    </TextBlock>
+                </Button>
             </Grid>
         <Label HorizontalAlignment="Center" Name="ResultsLabel" Content="{Binding ResultsLabel}"></Label>
        </StackPanel>