Combobox selectionchanged event in MVVM

Question

Hi Friends, How to bind the itemsource to combobox through MVVM and how to get the selected data in MVVM on a button click.

Sachidanand Suraj · Answer

1. Declare the ComboxItems as collectionView in ViewModel- public CollectionView comboBoxItems { get; set; } 2. Set the list Data on load by calling it at the time of load VerticalAlignment="Top"> /// /// Method to get the combobox data on load (View Model Code) maybe in constructor /// private void GetListData() { ListData = new ObservableCollection (); StudentModel model = new StudentModel(); ListData = model.GetListData(); //Getting the data from the model comboBoxItems = new CollectionView(model.GetListData()); //assign that data to the //collection view comboBoxItems.MoveCurrentTo(ListData[0]); comboBoxItems.CurrentChanged += ComboBoxItems_CurrentChanged; } 3. Way to get the selected data on selection changed of the dropdown list /// /// Method to select the selected items when the data of the list changed (View Model code) /// /// /// private void ComboBoxItems_CurrentChanged(object sender, EventArgs e) { if(Loaded) //Loaded is bool variable which is initially set to false, MessageBox.Show((((CollectionView)sender).CurrentItem).ToString()); Loaded = true; } 4. Get the combo Box data on button click Command="{Binding GetData}" /> 5. ViewModel Code public ICommand GetData { get; set; } in the constructor GetData = new RelayCommand(GetItemsData); /// /// Method to get the combo Box data on click of event /// /// private void GetItemsData(object obj) { var Item = comboBoxItems.CurrentItem; MessageBox.Show(Item.ToString()); }

Juan Francisco Morales Larios · Answer

I would miss you configured the combobox SelectedItemProperty with one property of your ViewModelClass. A picture is worth more than athousand words

Rohit Nair · Answer

Hi,It works perfectly and thanks for that! Now I have written a method inside combo box change event which gives content name and IsSlected property of checkbox for eg:{"ABC",true}, {"PQR,"false} Based on the values the view is not updating as it should be ABCchecked and PQR unchecked, but both are checked. How can i achieve this?