Why does the radio button ".Checked" result in an error?

Simply because Checked is an event not a boolean property and in C#,events can only be used with += or -= to attach or remove handlers which is why gRBuEradicatedBlueCities.Checked = false gives CS0079. RadioButton uses the IsChecked property to store whether it is selected.

https://learn.microsoft.com/en-us/dotnet/api/system.windows.controls.radiobutton?view=windowsdesktop-10.0

so try this instead:

gRBuEradicatedBlueCities.Background =
    (SolidColorBrush)(new BrushConverter().ConvertFrom("#0000ff"));

gRBuEradicatedBlueCities.IsChecked = false;

and if you want to react when the radio button becomes checked then use the event like this:

gRBuEradicatedBlueCities.Checked += gRBuEradicatedBlueCities_Checked;

and define:

private void gRBuEradicatedBlueCities_Checked(object sender, RoutedEventArgs e)
{
    // do lalalalalala
}

1 Reply

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Amira Bedhiafi4mo ago
Accepted answer
Simply because Checked is an event not a boolean property and in C#,events can only be used with += or -= to attach or remove handlers which is why gRBuEradicatedBlueCities.Checked = false gives CS0079. RadioButton uses the IsChecked property to store whether it is selected.
https://learn.microsoft.com/en-us/dotnet/api/system.windows.controls.radiobutton?view=windowsdesktop-10.0
so try this instead:
```
gRBuEradicatedBlueCities.Background =
    (SolidColorBrush)(new BrushConverter().ConvertFrom("#0000ff"));

gRBuEradicatedBlueCities.IsChecked = false;
```
and if you want to react when the radio button becomes checked then use the event like this:
```
gRBuEradicatedBlueCities.Checked += gRBuEradicatedBlueCities_Checked;
```
and define:
```
private void gRBuEradicatedBlueCities_Checked(object sender, RoutedEventArgs e)
{
    // do lalalalalala
}
```