Example needed on drag and drop between cxgrid and treeview

Paer Toernell

created 6 years ago

Hello,

I'm trying to see how drag and drop works, but the CXGRID drag and drop demo is unusable for me. I am very, very impressed that you have created the "DragDropDemoMain" cxgrid without any Views. I don't know how you load the views into the grid and i don't really care. I care about trying to track down the mechanisms of the drag and drop, and without having a view connected to a event that's not so easy.

I also want to find out how the DataController.FocusedRecordIndex; is connected to the key of my underlying database, but that is hard because then by a lot of reverse engineering i have to somehow find out the field list from the XML document that is loaded into the clientdatasets…

In essence, i have to spend A LOT of time on reverse engineering just to understand your demos before i can get started with the drag and drop.

Som what i need is some simple demo for drag and drop between cxgrid and treview and a goodand USABLE explanation of how to IMPLEMENT the DataController.FocusedRecordIndex (not just another "explanation" that is technically correct but don't explain anything) .

Regards, Pär.

Answers approved by DevExpress Support

DevExpress Support Team

created 6 years ago

Hello Pär,

We do not have a simpler demo for this task. Attached is a small sample project I created to demonstrate Drag And Drop operations. I hope this example will be of help.

Here are the actions you need to perform to enable Drag And Drop in TcxGrid:

Set the Grid View's DragMode property to dmAutomatic.
Handle the target control's OnDragOver event to accept Drop operations.
Implement the target control's OnDragDrop event to place a dropped data record into this control.
Use the DataController.FocusedRecordIndex property to get any value of a focused record.

Please review the "TcxCustomGridView.DragMode" and "Implementing Drag-And-Drop Functionality" help topic and related articles for additional information.

dxSample.ZIP

Comments (2)

Paer Toernell 6 years ago

I was unclear. I already find some example about how to drag from a grid to a treeview. Its the other way i need. From a treeview to a cxgrid. How to identify the record involved in both components.

Paer Toernell 6 years ago

Finally i solved it. Nowhere in any demo or in any help file could i find how to get the info from the Source (when a Treeview)

In the event …TableView1DragDrop(Sender, Source: TObject; X,
Y: Integer);

Var

ANode: TcxTreeListNode;
aNodeVar : Variant;
treeCol : TcxDBTreeListColumn;

Begin

ANode := TcxDBTreeList(Source).FocusedNode;
treeCol:=TcxDBTreeList(Source).GetColumnByFieldName('ID');
aNodeVar:=ANode.Values[treeCol.ItemIndex];

Well, i found thousands of lines with text for the advanced stuff i not yet need, but the very few lines i needed to get started was not there.

Best regards, Pär

Example needed on drag and drop between cxgrid and treeview

Answers approved by DevExpress Support

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