How can I disable combobox before button clicked in WPF MVVM - wpf

Question

In my project I have a "Generate Reports" Button and a "Select Location" ComboBox. I want the user to be unable to choose a location before clicking
"Generate Report" Button.
the xaml containing the combobox and the button:
<Button Content="Generate Reports" Command="{Binding GenerateReportsCommand}" Height="36" Margin="4" />
<ComboBox Grid.Column="2" ItemsSource="{Binding Locations}" SelectedItem="{Binding SelectedLocation}">
<i:Interaction.Triggers>
<i:EventTrigger EventName="SelectionChanged">
<i:InvokeCommandAction Command="{Binding LocationFilterCommand}" />
</i:EventTrigger>
</i:Interaction.Triggers>
</ComboBox>
What can I do in the ViewModel or UI? Thank you for all your helps.

Answer 1

I'm going to assume you know how to use data binding (based on your post you already use it).
Create a new Boolean in your ViewModel and bind the ComboBox's IsEnabled to it. (Something like IsEnabled="{Binding YOURBOOLEAN}")
Update that Boolean from your GenerateReportsCommand after the user successfully generated the report. If you set that variable to true, the ComboBox's IsEnabled will also be set to true.

Answer 2

You should have an additional property inside the ViewModel.
private bool _areReportsGenerated = false;
public bool AreReportsGenerated
{
get => _areReportsGenerated;
set
{
_areReportsGenerated = value;
OnPropertyChanged(); // you method's implementation of INotifyPropertyChanged
}
}
If you don't have an implementation of INotifyPropertyChanged you can take a look at Microsoft one.
Inside GenerateReportsCommand you should set AreReportsGenerated to true.
In the xaml then you only have to bind the newly created property to the IsEnabled property of the ComboBox
<ComboBox Grid.Column="2" ItemsSource="{Binding Locations}" SelectedItem="{Binding SelectedLocation}" IsEnabled="{Binding AreReportsGenerated}">
<i:Interaction.Triggers>
<i:EventTrigger EventName="SelectionChanged">
<i:InvokeCommandAction Command="{Binding LocationFilterCommand}" />
</i:EventTrigger>
</i:Interaction.Triggers>
</ComboBox>
It should work.
I hope I was helpful.