Combobox selectionchanged event in MVVM

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

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());

}

3 Replies

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Rohit Nair8y ago
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?
Juan Francisco Morales Larios9y ago
I would miss you configured the combobox SelectedItemProperty with one property of your ViewModelClass.

A picture is worth more than athousand words
Sachidanand Suraj9y ago
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
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());
}