Binding ComboBox SelectedItem using MVVM

Question

I have a problem with the SelectedItem in my ComboBox.

Answer 1

    
        
        OK
    



        //student Class
        public class Student
        {
            public  int Id { set; get; }
            public string name { set; get; }
        }

        //set 2 properties in MainWindow.xaml.cs Class
        public ObservableCollection studentInfo { set; get; }
        public Student SelectedstudentInfo { set; get; }

        //MainWindow.xaml.cs Constructor
        public MainWindow()
        {
            InitializeComponent();
            bindCombo();
            this.DataContext = this;
            cmbData.ItemsSource = studentInfo;

        }

        //method to bind cobobox or you can fetch data from database in MainWindow.xaml.cs
        public void bindCombo()
        {
            ObservableCollection studentList = new ObservableCollection();
            studentList.Add(new Student { Id=0 ,name="==Select=="});
            studentList.Add(new Student { Id = 1, name = "zoyeb" });
            studentList.Add(new Student { Id = 2, name = "siddiq" });
            studentList.Add(new Student { Id = 3, name = "James" });

              studentInfo=studentList;

        }

        //button click to get selected student MainWindow.xaml.cs
        private void Button_Click(object sender, RoutedEventArgs e)
        {
            Student student = SelectedstudentInfo;
            if(student.Id ==0)
            {
                MessageBox.Show("select name from dropdown");
            }
            else
            {
                MessageBox.Show("Name :"+student.name + "Id :"+student.Id);
            }
        }