C# Discussion Boards - CodeProject

21-Jan-09 19:36

Hi EveryBody,

How to Drag and Drop Treeview Item into listview? Please help me out..

I have one parent node and two child nodes. when I drag a Parent Node, included child nodes are also to be dragged.
And all of them to be placed in listview row (3 columns).

Please help me out with a sample example. Itz very urgent for me Confused | :confused:

Udayaraju22-Jan-09 0:31

22-Jan-09 0:31

Please reply me

DaveyM6922-Jan-09 1:51

DaveyM69

22-Jan-09 1:51

Udayaraju wrote:
Itz very urgent for me

... but not urgent for us. I saw your post hours ago but ignored it because of this. Bumping your post will not get you any further.

I won't give you the code but I'll give you the theory so you can code it yourself. If you get stuck with a specific part of your code, post it and we'll have a look.

What you want is a very simple 3 step process.

In the treeview's mousedown event , get the node at the mouse point. Set the selectednode to be that node If it's not null and is a 'Parent' node, call the treeview's DoDragDrop method.

In the listview's dragover event, set the effect property of the event arguments to copy.

In the litview's DragDrop event, convert the data to a treenode (would be a good idea to null check here too) then convert it and it's nodes (children) to a listviewitem with listviewsubitems and add to your listview.

Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)

Udayaraju22-Jan-09 3:01

22-Jan-09 3:01

Hi,

Thanq for ur Suggestion But i tried inthes way..can you corect the problem here.

See the below code. Here I have a Problem. Treeview has already one root node and twochild nodes with it.
They have to be dragged and dropped in listview.

The main Problem is wen I drag an item..the Itemdrag event is not fired.?? Please try to resolve it.

private void tvwSalesProducts_ItemDrag(object sender, ItemDragEventArgs e)
{
tvwSalesProducts.DoDragDrop(e.Item, DragDropEffects.Copy | DragDropEffects.Move);
}

private void lstMultiProItems_DragEnter(object sender, DragEventArgs e)
{
e.Effect = DragDropEffects.Copy | DragDropEffects.Move;
}

private void lstMultiProItems_DragDrop(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent("System.Windows.Forms.TreeNode", false))
{
string[] Items = new string[5];
TreeNode SourceNode;
SourceNode = (TreeNode)e.Data.GetData("System.Windows.Forms.TreeNode");
Items[0] = Convert.ToString(SourceNode.Tag);
Items[1] = SourceNode.Text.ToString();
Items[2] = SourceNode.FirstNode.Text.ToString();
Items[3] = SourceNode.LastNode.Text.ToString();

lstMultiProItems.Items.Clear();
lstMultiProItems.Columns.Add("ID", 100, HorizontalAlignment.Left);
lstMultiProItems.Columns.Add("Product Name", 100, HorizontalAlignment.Left);
lstMultiProItems.Columns.Add("Selling Price", 100, HorizontalAlignment.Left);
lstMultiProItems.Columns.Add("Conversion", 100, HorizontalAlignment.Left);

ListViewItem Item1 = new ListViewItem(Items);
lstMultiProItems.Items.Add(Item1);
lstMultiProItems.AllowColumnReorder = false;
lstMultiProItems.FullRowSelect = true;
}
}

DaveyM6922-Jan-09 4:07

DaveyM69

22-Jan-09 4:07

Check out the working code below and compare - you should be able to figure it out from this.

/* Assumes
TreeView treeView1. Parent node must have Tag "Parent" and
exactly two child nodes for drag to work
ListView listView1 with three columns already added.

Events subscribed
treeView1.ItemDrag += new ItemDragEventHandler(treeView1_ItemDrag);
listView1.DragOver += new DragEventHandler(listView1_DragOver);
listView1.DragDrop += new DragEventHandler(listView1_DragDrop);
*/
void treeView1_ItemDrag(object sender, ItemDragEventArgs e)
{
    TreeNode nodeData = (TreeNode)e.Item;
    // set as selected
    treeView1.SelectedNode = nodeData;
    // check is parent using tag property
    if ((string)nodeData.Tag == "Parent" && nodeData.Nodes.Count == 2)
        // OK
        treeView1.DoDragDrop(nodeData, DragDropEffects.Copy);
}
void listView1_DragOver(object sender, DragEventArgs e)
{
    // default to none
    e.Effect = DragDropEffects.None;
    // get tree node
    TreeNode nodeData = (TreeNode)e.Data.GetData(typeof(TreeNode));
    // check data in case coming from elsewhere
    if (nodeData != null && (string)nodeData.Tag == "Parent" && nodeData.Nodes.Count == 2)
        // OK so proceed
        e.Effect = DragDropEffects.Copy;

}
void listView1_DragDrop(object sender, DragEventArgs e)
{
    // get tree node
    TreeNode nodeData = (TreeNode)e.Data.GetData(typeof(TreeNode));
    // check data
    if (nodeData != null && (string)nodeData.Tag == "Parent" && nodeData.Nodes.Count == 2)
    {
        // convert
        ListViewItem newItem = new ListViewItem(nodeData.Text);
        foreach (TreeNode childNode in nodeData.Nodes)
        {
            ListViewItem.ListViewSubItem newSub = new ListViewItem.ListViewSubItem();
            newSub.Text = childNode.Text;
            // add children to parent
            newItem.SubItems.Add(newSub);
        }
        // add parent
        listView1.Items.Add(newItem);
    }
}

Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)

Udayaraju22-Jan-09 4:14

22-Jan-09 4:14

Thanq very mUch Dave..... these may help me a Lot.

I wil go through It and cum with u New errors..
Jus Kidding Thumbs Up | :thumbsup:

Udayaraju22-Jan-09 4:10

Issue with the Windows Service OnTimeElapsed

22-Jan-09 4:10

Guys Please Help me out,

I have added the event handlers from front end design. but still the event is not fired.
Can u please tel me wther the code is correct or not

mpavas21-Jan-09 19:33

mpavas

21-Jan-09 19:33

Hello,

I have a below issue with the windows service.

I have a method as below
private void OnElapsedTime(object source, ElapsedEventArgs e)
{
log.Info("OnElapsedTime");
BillPay.ProcessOrder();

}
I have a timer set for 1 mins in OnStart method
protected override void OnStart(string[] args)
{

//ad 1: handle Elapsed event
timer.Elapsed += new ElapsedEventHandler(OnElapsedTime);
//ad 2: set interval to 1 minute (= 60,000 milliseconds)
timer.Interval = 60000 ;
//ad 3: enabling the timer
timer.Enabled = true;
}

The problem:
If my ProcessOrder() method which process all orders do not get completed in 1 mins I see unexpected results in the database with duplicate entry. I suspect the method ProcessOrder() get called again onTimeElapsed, I have commit and rollback statements too. But does not help.

Please suggest as how can I resolve this issue.

Regards,
Pavas

Guffa21-Jan-09 21:51

Guffa

21-Jan-09 21:51

Stop the timer while you call the method, so that it does not start the event handler in another thread.

Despite everything, the person most likely to be fooling you next is yourself.

mpavas21-Jan-09 21:57

mpavas

21-Jan-09 21:57

So when it will again start?

Regards,
Pavas

mpavas21-Jan-09 22:18

mpavas

21-Jan-09 22:18

I believe, timer will start right after the method call is over..let me try this

Regards,
Pavas

Guffa22-Jan-09 0:45

Guffa

22-Jan-09 0:45

It will start when you turn the timer on again.

Despite everything, the person most likely to be fooling you next is yourself.

#realJSOP22-Jan-09 0:21

#realJSOP

22-Jan-09 0:21

Put your work into a thread, and fire off the thread each time the timer ticks. You can even prevent multiple threads from kicking off with appropriate code in the tick handler.

Personally, I wouldn't use a Timer object because it's the lowest priority message in Windows, and in a busy system, there's no guarantee the message will even be handled. Instead, I use a BackgroundWorker object for timers because they can be easily aborted. Sure, it's more code (go forbid a programmer should have to actually write some code), but it's much more reliable and controllable.