How to detect if a Checkbox is switched on and off and write those changes back to the datasource?

Question

 <DataGrid Name="employeesDataGrid" AutoGenerateColumns="False">
        <DataGrid.Columns>
            <DataGridCheckBoxColumn
                xmlns:myconv="clr-namespace:MyProject.Converters"
                Binding="{Binding enabled, Converter={myconv:IntToBool}}"
                Header="Enabled">
                <DataGridCheckBoxColumn.CellStyle>
                    <Style>
                        <EventSetter Event="CheckBox.Checked" Handler="OnChecked" />
                    </Style>
                </DataGridCheckBoxColumn.CellStyle>
            </DataGridCheckBoxColumn>
            <DataGridTextColumn 
                Binding="{Binding proxyFor}"
                Header="Proxy For"
                />
        </DataGrid.Columns>
    </DataGrid>

Code Behind

    private void OnChecked(Object sender, RoutedEventArgs e)
    {
        // Not sure what to do here.
    }

How do I keep track of whats changed in the DataTable or the selected row?

I am loaded this at Initialize() with the following code

        using (OleDbConnection con = new OleDbConnection(connectionString))
        {
            dt = new DataTable("accesscontrol");

            CmdString = "SELECT proxyFor, enabled FROM accesscontrol WHERE currentlyLoggedOnUser = @userName";
            OleDbCommand cmd = new OleDbCommand(CmdString, con);
            cmd.Parameters.AddWithValue("userName", Environment.UserName);
            using (adapter = new OleDbDataAdapter(cmd))
            {
                adapter.Fill(dt);
            }                    
            employeesDataGrid.ItemsSource = dt.DefaultView;

Answer 1

This is what I would do; I would add an intermediate step in between the data loading. I would transfer the data that you have loaded into a Model which would have the properties corresponding to the types I need and do the binding against the models. All of the changes that are being made would be preserved in the models you have created.

This will give you some significant advantages, in the fact that you will not have to keep track of the individual changes and organize them in such a fashion. This will also allow you to keep the UI interaction "cleaner" per say. Making the code more readable and concise.

If you are running a MSSQL Server you might want to have a look into Entity Framework. It would make this work much easier.

This will be roughly how you translate your models based off of the OleDBConnection documentation

//this list should be declared out of this scope and be declared in the main class
List<YourDbModel> models = new List<YourDbModel>();   
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
    OleDbCommand command = new OleDbCommand(queryString, connection);
    connection.Open();
    OleDbDataReader reader = command.ExecuteReader();
    while (reader.Read())
    {
        // translate the properties of your query to your model.
        YourDbModel model = new YourDBModel();
        model.property = reader[0].ToString();
        models.add(model);
    }
    reader.Close();
}   

You then need to set your itemsource for the DataTable. Currently you are doing this manually I prefer MVVM style but for consistency I will do it your way.

Initilize();
employeesDataGrid.ItemSource = models;

Now you will need to reconfigure your columns to match the newly created models. After you set your binding that go from the columns to the properties of each individual model, the changes will automatically reflect from your to your models. If you want to reflect the changes from your model to your view you will need to have a proper viewmodel.

I would also like to urge you to investigate the MVVM way of doing binding, this makes WPF significantly easier and more fun to work with.

Answer 2

The proper way to handle this would be to use databinding.

1. Create your data models (they should have a boolean property that you can bind your check box to)
2. Put said data models into an observable collection
3. Bind your datagrid to your observable collection

When your check box is checked or unchecked the setter in the model will trigger. This can then be used to run what ever operations you'd like.

I could give you an exact example of this but there is maybe a billion of them already in existence. So to prevent further repetitiveness on the internet here's a few links...

What Is DataBinding

Datagrid binding in WPF

WPF checkbox binding

Answer 3

No need to detect if your CheckBox is bound to a Boolean Property of your DataSource. Property will be updated automatically.