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Scroll to row when programmatically setting selected item
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This is a migrated thread and some comments may be shown as answers.
Maria
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Maria asked on 08 Dec 2010, 03:36 PM
Hello,

I'm trying to implement a "find" feature where the user can enter a value in a textbox (outside of the grid) then click a button to find the row that matches the search criteria.  I'm able to programmatically set the selectitem on the grid successfully, but if the item is not in the current scroll region the user has to scroll down to to the item.  Is there a way to ensure that the selected item is always in view?  Also, I should mention that we are using MVVM, so there is no code behind.

Thanks.

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Vlad
Telerik team
answered on 08 Dec 2010, 03:49 PM
Hi,

 You can use our ScrollIntoView() method to achieve your goal. Since your using MVVM you can create your custom attached behavior to do this - you can check for the project in this blog post for more info about attached behaviors. 

Kind regards,
Vlad
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Thomas
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answered on 20 Jul 2011, 02:10 PM
The blog did not help me. Can you please give a example for this problem?

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Erik
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answered on 18 Aug 2012, 01:48 PM
This is what I came up with

In your ViewModel:
private Requirement _scrollIntoViewObject;
public Requirement ScrollIntoViewObject
{
    get { return _scrollIntoViewObject; }
    private set
    {
        _scrollIntoViewObject = value;
        OnPropertyChanged("ScrollIntoViewObject");
    }
}

In your RadGridView:
<telerik:RadGridView ItemsSource="{Binding MyItems}">
      <i:Interaction.Behaviors>
            <Utils:RadGridScrollIntoViewBehavior/>
      </i:Interaction.Behaviors>
</telerik:RadGridView>

And lastly:
public class RadGridScrollIntoViewBehavior : Behavior<RadGridView>
{
    private RadGridView Grid
    {
        get
        {
            return AssociatedObject;
        }
    }
 
    protected override void OnAttached()
    {
        base.OnAttached();
 
        Grid.DataContextChanged += GridDataContextChanged;
    }
 
    private void GridDataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
    {
        if (e.OldValue != null)
        {
            ((INotifyPropertyChanged) e.OldValue).PropertyChanged -= DataContextOnPropertyChanged;
        }
        if (e.NewValue != null)
        {
            ((INotifyPropertyChanged) e.NewValue).PropertyChanged += DataContextOnPropertyChanged;
        }
    }
 
    private void DataContextOnPropertyChanged(object sender, PropertyChangedEventArgs e)
    {
        if (!e.PropertyName.Equals("ScrollIntoViewObject")) return;
 
        var propertyInfo = sender.GetType().GetProperty(e.PropertyName);
        var scrollIntoViewObject = propertyInfo.GetValue(sender, null);
 
        if(scrollIntoViewObject != null)
        {
            Grid.ScrollIntoView(scrollIntoViewObject);
        }
    }
}

There must be a better solution without the propertyname and the reflection, but this works in my scenario
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Lawrence
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answered on 10 Feb 2015, 02:33 PM
Here's an Extension method that I wrote that will scroll into view and select the row with a data pager.

public void ScrollIntoView<T>(T dataItem, RadDataPager radDataPager)
{
    var items = (Collection<T>)this.ItemsSource;
    int index = items.IndexOf(dataItem);
    int page = (int)Math.Floor((double)index / radDataPager.PageSize);
 
    radDataPager.MoveToPage(page);
 
    this.SelectedItem = items[index];
    this.ScrollIntoView(this.SelectedItem);
}
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MG
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answered on 07 Jul 2015, 06:34 AM

Based on Erik's post, here is another attempt..

public class RadGridViewScrollIntoViewBehavior: Behavior<RadGridView>
    {
        private RadGridView Grid
        {
            get { return AssociatedObject; }
        }
 
        protected override void OnAttached()
        {
            base.OnAttached();
            Grid.Items.CollectionChanged += Items_CollectionChanged;
        }
 
        private void Items_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
        {
            if (e.Action == NotifyCollectionChangedAction.Add)
            {
                var myRow = e.NewItems[0] as MyClassType;
                if (labelSet != null)
                {
                    Grid.ScrollIntoView(myRow );
                }
            }
        }
    }

In the RadGridView,

<telerik:RadGridView ItemsSource="{Binding MyItems}">
      <i:Interaction.Behaviors>
            <Utils:RadGridScrollIntoViewBehavior/>
      </i:Interaction.Behaviors>
</telerik:RadGridView>

 

Thanks

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Dimitrina
Telerik team
answered on 07 Jul 2015, 08:38 AM
Hi,

You can check the documentation on Scroll to a particular row or column on the different options RadGridView suggests and how the scroll methods are expected to work.

Regards,
Dimitrina
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Dan
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answered on 01 Apr 2016, 02:22 PM
public class RadGridViewScrollSelectedItemIntoViewBehavior : Behavior<RadGridView>
    {
        #region Overrides
        protected override void OnAttached()
        {
            base.OnAttached();
            AssociatedObject.Unloaded += OnUnloaded;
            AssociatedObject.SelectionChanged += OnSelectionChanged;
        }
 
         
        #endregion
 
        #region Implementation
        private void OnUnloaded(object sender, System.Windows.RoutedEventArgs e)
        {
            AssociatedObject.Unloaded -= OnUnloaded;
            AssociatedObject.SelectionChanged -= OnSelectionChanged;
        }
        private void OnSelectionChanged(object sender, SelectionChangeEventArgs e)
        {
            object si = AssociatedObject.SelectedItem;
            if (si != null)
            {
                AssociatedObject.ScrollIntoView(si);
            }
        }
 
 
        #endregion
    }
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Stefan Nenchev
Telerik team
answered on 04 Apr 2016, 01:17 PM
Hello Dan,

Thank you for providing the additional approach and contributing to the Telerik community.

Regards,
Stefan Nenchev
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Dinesh
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answered on 07 Feb 2019, 06:08 AM
I just need some help on how to scroll HORIZONTALLY by using (SHIFT + MOUSE SCROLL) IN WPF application. Give some idea or Code & Project Solution....
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Dinesh
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answered on 08 Feb 2019, 09:38 AM
I just need some help on how to scroll HORIZONTALLY by using (SHIFT + MOUSE SCROLL) IN WPF application. Give some idea or Code & Project Solution...
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Dinesh
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answered on 08 Feb 2019, 09:43 AM
I just need some help on how to scroll HORIZONTALLY by using (SHIFT + MOUSE SCROLL) IN WPF application. Give some idea or Code & Project Solution...
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Shanthosh
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answered on 11 Feb 2019, 09:36 AM

using telerik not working on shift + mousewheel 

try this code without telerik

 private void ScrollViewer_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
        {  
             ScrollViewer scrollviewer = sender as ScrollViewer;

            if (Keyboard.Modifiers == ModifierKeys.Shift)
            {
                if (e.Delta > 0)
                    scrollviewer.PageLeft();
                else
                    scrollviewer.PageRight();
                e.Handled = true;
            }
        }

xaml code:

<ScrollViewer HorizontalScrollBarVisibility="Visible" VerticalScrollBarVisibility="Visible" PreviewMouseWheel="ScrollViewer_PreviewMouseWheel" />

 

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Vladimir Stoyanov
Telerik team
answered on 11 Feb 2019, 11:20 AM
Hello Dinesh,

I replied to your question in the other forum thread: https://www.telerik.com/forums/ctrl-mousescroll-for-zoom-mousescroll-for-scrolling#_sxWZEbW80ySdQ1Swtiruw.

Regards,
Vladimir Stoyanov
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Maria
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Vlad
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Thomas
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Erik
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Lawrence
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MG
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Dimitrina
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Dan
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Stefan Nenchev
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Dinesh
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Shanthosh
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Vladimir Stoyanov
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