ListView DataBindig using MVVM (WPF, ListView, Binding)

Question

I have model called ListViewModel with one method:

namespace LayoutMVVM.ViewModels
{
    public class ListViewModel
    {
        public void getData()
        {
        testViewClassDataContext tv = new testViewClassDataContext();
        List<test_view> tvq = (from tt in tv.test_views
                               select tt).ToList();
        }
    }
}

Into my UserControl called ListView I want to get result from model and bind to List:

ListView.xaml:

<UserControl .....>    
    <Grid Background="Crimson">

        <ListView Width="230" Height="250"  Name="lvMyList">
            <ListView.View>
                <GridView>
                    <GridViewColumn Header="FirstName" Width="90" DisplayMemberBinding="{Binding FirstName}" />
                    <GridViewColumn Header="LastName" Width="90" DisplayMemberBinding="{Binding LastName}" />
                    <GridViewColumn Header="Type" Width="50" DisplayMemberBinding="{Binding Type}" />
                </GridView>
            </ListView.View>
        </ListView>

    </Grid>
</UserControl>

ListView.cs

namespace LayoutMVVM.Views
{
    public partial class ListView : UserControl
    {
        public ListView()
        {
            InitializeComponent();

            ListViewModel lvm = new ListViewModel();
            lvMyList.ItemsSource = lvm.getData(); //error 
        }
    }
}

I'm starting with WPF and don't know how to correclty bind data.

Sajeetharan · Accepted Answer · 2017-04-14 12:53:29Z

4

Probably you should change the method as follows, so that method will return actual results,

public List<test_view> getData()
    {
        testViewClassDataContext tv = new testViewClassDataContext();
        List<test_view> tvq = (from tt in tv.test_views
                               select tt).ToList();
        return tvq;
    }

answered Apr 14, 2017 at 12:53

Sajeetharan

223k65 gold badges370 silver badges409 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

4est Over a year ago

@@Sajeetharan - thanks, one question: it's ok with MVVM or should I change something?

Sajeetharan Over a year ago

Yeah it's totally fine

4est Over a year ago

thanks, because Naresh wrote to use this.DataContext = lvm....instead of my lvMyList.ItemsSource = lvm.getData();

Naresh Ravlani · Accepted Answer · 2017-04-14 13:20:28Z

1

Sajeetharan's answer looks fine but if you want to go ahead with MVVM, replace code behind code like this:

namespace LayoutMVVM.Views
{
    public partial class ListView : UserControl
    {
        public ListView()
        {
            InitializeComponent();
            ListViewModel lvm = new ListViewModel();
            this.DataContext = lvm; //this is what you are missing                
        }
    }
}

and assign ItemsSouce of ListView in XAML like this:

        <ListView Width="230" Height="250"  Name="lvMyList" ItemsSource="{Binding tvq}" >
            <ListView.View>
                <GridView>
                    <GridViewColumn Header="FirstName" Width="90" DisplayMemberBinding="{Binding FirstName}" />
                    <GridViewColumn Header="LastName" Width="90" DisplayMemberBinding="{Binding LastName}" />
                    <GridViewColumn Header="Type" Width="50" DisplayMemberBinding="{Binding Type}" />
                </GridView>
            </ListView.View>
        </ListView>

You will have to create a list property List(or ObservableCollection) "tvq" and populate it by calling getData() in ViewModel.

I would suggest you read more about MVVM and bindings. Happy coding !!

edited Apr 14, 2017 at 13:20

answered Apr 14, 2017 at 13:05

Naresh Ravlani

1,63014 silver badges29 bronze badges

7 Comments

Sautins Over a year ago

He is setting directly the itemsource and so, if the getdata() method would return something, it should work anyway without setting the datacontext.

Naresh Ravlani Over a year ago

@CiccioRocca : Got your point. Bt anyways if he wants to go with MVVM, I think my answer would be useful.

Sautins Over a year ago

Yes it is a good suggestion, but the reason his program doesn't work is not related to DataContext, but it's the fact that getData method is a Void and so the line :lvMyList.ItemsSource = lvm.getData(); doesn't make any sense.

4est Over a year ago

so how can I use data his.DataContext = lvm to load data? as now after I change method as Sajeetharan said I using lvMyList.ItemsSource = lvm.getData();

Sautins Over a year ago

@4est Now that you've changed the getData as told you Sajeetharan, you could set Itemssource with Databinding as suggested Naresh Ravlani. Merge the two answers ;)

|

Sautins · Accepted Answer · 2017-04-14 14:44:39Z

I'm adding this response to integrate what have been told in the previous response:

First of all change the method getData as told you Sajeetharan:

public List<test_view> getData()
    {
        testViewClassDataContext tv = new testViewClassDataContext();
        List<test_view> tvq = (from tt in tv.test_views
                               select tt).ToList();
        return tvq;
    }

The second thing to do is changing code behind as told you Naresh Ravlani:

public partial class ListView : UserControl
    {
        public ListView()
        {
            InitializeComponent();
            ListViewModel lvm = new ListViewModel();
            this.DataContext = lvm; //this is what you are missing                
        }
    }

Third pay attention that the equivalent you have also tell to your view that the list has an itemssource:

        <ListView Width="230" Height="250"  Name="lvMyList" ItemsSource="{Binding}" >
            <ListView.View>
                <GridView>
                    <GridViewColumn Header="FirstName" Width="90" DisplayMemberBinding="{Binding FirstName}" />
                    <GridViewColumn Header="LastName" Width="90" DisplayMemberBinding="{Binding LastName}" />
                    <GridViewColumn Header="Type" Width="50" DisplayMemberBinding="{Binding Type}" />
                </GridView>
            </ListView.View>
        </ListView>

Look at this:

<ListView Width="230" Height="250"  Name="lvMyList" ItemsSource="{Binding}" >

Note that you have to tell to the listview to take its itemsource from Datacontext using DataBinding (ItemSource = "{Binding}").

I hope it will help you!

Collectives™ on Stack Overflow

ListView DataBindig using MVVM (WPF, ListView, Binding)

3 Answers 3

3 Comments

7 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

3 Comments

7 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related