Drag and Drop functionality with RadGridView and Re-ordering Grid Row

[Pradnya]

Hi

how to implement drag and drop functionality with RadGridView and on drop I want replace specific column value.

Please help me how can I Implement this scenario.

Note: I have implemented Re-ordering functionality with same GridView.

Thanks-

 

[Nick]

Hello Pradnya,

You can add Drop handler to the header row and use it to modify the column that you just dropped upon. 

public MainPage()
{
    RadDragAndDropManager.ExecutionMode = DragExecutionMode.Disabled;

    InitializeComponent();

    this.radGridView1.RowLoaded += new EventHandler<RowLoadedEventArgs>(radGridView1_RowLoaded);
}

void radGridView1_RowLoaded(object sender, RowLoadedEventArgs e)
{
    if (e.Row is GridViewHeaderRow)
    {
        DragDropManager.AddDropHandler(e.Row, OnColumnHeaderDrop, true);
    }
}

private void OnColumnHeaderDrop(object sender, Telerik.Windows.DragDrop.DragEventArgs args)
{
    var column = ((args.OriginalSource as FrameworkElement).ParentOfType<GridViewHeaderCell>()).Column;
}

Hope this helps! 

Regards,
Nik
the Telerik team

[Pradnya]

Thank you for your reply,

if I make ExecutionMode = DragExecutionMode.Disabled then how can I register AddDragQueryHandler, AddDropQueryHandler.

Can you please provide some sample for above scenario.

Thanks-

[Pradnya]

I mean I want to update specific column and Specefic row value not a column header value.

[Nick]

Hi Pradnya,

In that case you have to set RadDragAndDropManager.AllowDrop to true on the Cells on which you need to drop. that way in the DropInfo handler, the destination will be the GridViewCell instead of the GridViewRow. 

Hope this helps! 

Greetings,
Nik
the Telerik team

[Pradnya]

Where I can set RadDragAndDropManager.AllowDrop to true on the Cells in xaml or in code behind

Thanks-

[Pradnya]

I tried using following way

public TestPage(RuleAuthoringViewModel ruleViewModel)
        {
            RadDragAndDropManager.ExecutionMode = DragExecutionMode.Disabled;

            InitializeComponent();

            RadDragAndDropManager.AddDragQueryHandler(list, OnDragQuery);
            RadDragAndDropManager.AddDropQueryHandler(gridview1.Columns[3], OnDropQuery);
            RadDragAndDropManager.AddDragInfoHandler(list, OnDragInfo);
            RadDragAndDropManager.AddDropInfoHandler(gridview1.Columns[3], OnDropInfo);

            RadDragAndDropManager.SetAllowDrop(gridview1.Columns[3], true);
}

Getting following error
Object reference not set to an instance of an object.

[Nick]

Hello Pradnya,

You can subscribe to the RowLoaded event of the GridView and set it there.

void GridView1_RowLoaded(object sender, RowLoadedEventArgs e)
{
    if (e.Row is GridViewRow)
    {
        foreach (var cell in e.Row.Cells)
        {
            RadDragAndDropManager.SetAllowDrop(cell, true);
        }
    }
}

Hope this helps!  All the best,
Nik
the Telerik team