为什么使用`Checked`属性会导致奇怪的错误，事件只能发生在+ =或 - =的右边？

Question

I am working on c# on a WPF application.I have written the following code

public partial class MainWindow : Window
{
    public MainWindow()
    {
        RadioButton daw;
        InitializeComponent();

        if (qoneone.Checked == true)
        {
            MessageBox.Show("Correct");

        }
    }

A error occurs that says

event qoneone.Checked can only appear on left hand side of += or -=

Answer 1

You are accessing the wrong member of qoneone .

Instead you have to check the boolean property qoneone.IsChecked == true .

IsChecked is a property that you can read or write to get or change the current state of the RadioButton .

But Checked is an event . (You could attach an handler to it using += so you can do something when the RadioButton state change. Hence the error message.)

Answer 2

As giangregorio has stated, quone.checked is a property and this requires an event.

What you should be doing here is a delegate:

QueoneChanged += quoneevent;

quoneevent (Object sender, routed event s)
{
  \\insert code here

}