CODEWITHSUNDEEP
c#wpfxamltreeviewmouseevent
arjacsoh
arjacsoh

Reputation: 9232

Mouse events on Treeview

I want in the window of a wpf to set a treeview and make use of it through mouse events. Particularly, I would like a complex shape to be drawn on a canvas by a mouseclick on each item of the treeview. However I am not sure if the treeview can serve this purpose, since the implementation I made does not seem to work at all. The mouse events do not work (the delegates are not triggered). Could someone indicate me the reason? Have a look at the code:

<TreeView DockPanel.Dock="Left" Background="DarkGray" HorizontalAlignment="Left" VerticalAlignment="Top">
    <TreeViewItem Header="Input Data">
        <TreeViewItem Header="Vector" MouseEnter="create_Rhombus"/>
        <TreeViewItem Header="Array"/>
    </TreeViewItem>
    <TreeViewItem Header="Maths">
        <TreeViewItem Header="Add" MouseDown="create_AddRectangle"/>
        <TreeViewItem Header="Subtract" MouseDown="create_SubtractRectangle"/>
        <TreeViewItem Header="Multiply" MouseDown="create_MultiplyRectangle"/>
        <TreeViewItem Header="Divide" MouseDown="create_DivideRectangle"/>
    </TreeViewItem>
</TreeView>

The methods in the code behind file are:

private void create_AddRectangle(object sender, MouseButtonEventArgs e)

private void create_SubtractRectangle(object sender, MouseButtonEventArgs e)

….

However the above methods are not invoked. Why?

Upvotes: 0

Views: 1886

Answers (2)

brandonstrong
brandonstrong

Reputation: 688

I think there might be a bug with using tunneling (ie PreviewMouseDown). I implemented it and it fires correctly but if I try to access the DataContext I get a {DisconnectedItem} object. From the reading I've done online, this appears to be a bug with WPF.

I did find that I can wire a MouseLeftButtonDown and a MouseRightButtonDown events for a single TreeViewItem to the same method and it will work exactly the same way you'd expect the MouseDown event to work.

Upvotes: 0

brunnerh
brunnerh

Reputation: 184386

That is presumably because of the selection functionality, the mouse event is being marked as handled internally. Try using the tunneling versions of such events (i.e. PreviewMouseDown) instead.

Upvotes: 2

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