Is any difference between the datacontext sets in code behind and xaml?

Question

I am using the DataGridComboBoxColumn, and if I set the datacontext to the Window in XAML means the ItemsSource loaded fine in combobox column. If I set the datacontext to the window in code behind in MainWindow constructor after the InitializeComponent(), Itemssource not loaded in the combobox column.

Could you please share any suggestion on this ?

Code :

<Window.DataContext>
        <local:OrderInfoRepositiory/>
    </Window.DataContext>

<DataGrid Name="dataGrid1"
                  Width="308"
                  Height="200"
                  HorizontalAlignment="Left"
                  VerticalAlignment="Top"
                  AutoGenerateColumns="False"
                  ItemsSource="{Binding OrderInfoCollection}">
            <DataGrid.Columns>

                <DataGridComboBoxColumn x:Name="ComboBoxColumn"                                        
                                        Header="Position"
                                        ItemsSource="{Binding ComboItemSource}"
                                         />
                <DataGridTextColumn Binding="{Binding OrderID}" Header="Name" />
            </DataGrid.Columns>
        </DataGrid>

OrderInfoRepository definition:

public class OrderInfoRepositiory : INotifyPropertyChanged
    {

        private ObservableCollection<string> comboitemSource;

        public ObservableCollection<string> ComboItemSource
        {
            get
            {
                return comboitemSource;
            }
            set
            {
                comboitemSource = value;
                RaisePropertyChanged("ComboItemSource");
            }
        }

        ObservableCollection<OrderInfo> orderCollection;
        public ObservableCollection<OrderInfo> OrderInfoCollection
        {
            get { return orderCollection; }
            set { orderCollection = value; RaisePropertyChanged("OrderInfoCollection"); }
        }        
        public OrderInfoRepositiory()
        {
            orderCollection = new ObservableCollection<OrderInfo>();
            OrderInfoCollection = GenerateOrders();

            ComboItemSource = new ObservableCollection<string>();
            ComboItemSource.Add("Germany");
            ComboItemSource.Add("Mexico");
            ComboItemSource.Add("Sweden");
            ComboItemSource.Add("France");
            ComboItemSource.Add("Spain");
            ComboItemSource.Add("Canada");
        }
}

I have added the code in mainwindow.xaml, please help me. its urgent requirement. — Elavarasan M, Oct 20 '15 at 04:49
Try this in your code behind `ComboBoxColumn.ItemSource=YourDataScource` — Thirisangu Ramanathan, Oct 20 '15 at 05:00
No, if i set the datacontext to the window from code behind, combobox column itemssource not loaded. In the above code, i have set the datacontext to the window in XAML. — Elavarasan M, Oct 20 '15 at 05:01
There is in theory no difference between assigning the `DataContext` value in XAML vs code-behind. People with urgent requests should be _especially_ careful to [present their question in a clear, answerable way](https://stackoverflow.com/help/how-to-ask). Please provide [a good, _minimal_, _complete_ code example](https://stackoverflow.com/help/mcve) that reliably reproduces the problem you are trying to fix. — Peter Duniho, Oct 20 '15 at 05:01
@ElavarasanM this may help you : http://stackoverflow.com/questions/5824600/databind-from-xaml-to-code-behind — Thirisangu Ramanathan, Oct 20 '15 at 05:11
is any option to set the itemssource to the combobox column without using the relativesource ? — Elavarasan M, Oct 20 '15 at 05:36
Can you post the code behind of the xaml? You might be making a small mistake when you do it from the code — Sandesh, Oct 20 '15 at 06:33
I would like to know if it's still urgent now? Or it has already been at deadline? — King King, Oct 20 '15 at 08:05
@ Sandeesh - Please find the below code behind code. 'this.DataContext=new OrderInfoRepository()'. thats all in the mainwindow constructor after the InitializeComponent(). — Elavarasan M, Oct 20 '15 at 08:29

score -1 · Answer 1 · answered Oct 20 '15 at 10:18

-1

There is a very small technical difference in setting the DataContext in xaml and the code behind.

When you define it in the xaml's code behind the UI will be initialized first and then the DataContext is initialized while if you define it in the xaml itself the DataContext is initialized while initializing the UI itself.

Unless you are missing the PropertyChanged notification in your DataContext there should not be any visible difference between defining the DataContext in xaml's code behind or xaml itself.

answered Oct 20 '15 at 10:18

Sandesh

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I have used the propertychanged. also by this http://www.thomaslevesque.com/2011/03/21/wpf-how-to-bind-to-data-when-the-datacontext-is-not-inherited/#comment-82716 one, i am able to acheive my requirement. Is any other way other than this ? – Elavarasan M Oct 21 '15 at 04:19
Can you post your class definition of `OrderInfoRepositiory`? – Sandesh Oct 21 '15 at 04:37

Is any difference between the datacontext sets in code behind and xaml?

1 Answers1