TreeView on Focus Leave - disable button

Question

I am trying to have a Button which

gets Enabled when a node in the TreeView is selected
gets Disabled when a node in the TreeView loses focus

My Form have two TreeViews:

TreeView containing Books
TreeView containing Loans

and when one of them has the current selection I want the other to de-select its item.

I also have a ComboBox in the Form.

When the TreeView with Loan(s) has an item selected I want to press a button to return this loan. But as soon as I try to press the button it gets disabled and I cannot interact with it.

I have tried to solve it like this:

private void treeViewLoans_AfterSelect(object sender, TreeViewEventArgs e)
{
    ReturnLoanButtonCheck();
}

private void treeViewLoans_Leave(object sender, EventArgs e)
{
    treeViewLoans.SelectedNode = null;
    ReturnLoanButtonCheck();
}

private void ReturnLoanButtonCheck()
{
    if (treeViewLoans.SelectedNode == null)
        buttonReturnLoan.Enabled = false;
    else if (treeViewLoans.SelectedNode != null)
        buttonReturnLoan.Enabled = true;
}

When I try to press the button the ComboBox gets focus instead.

What am I doing wrong here?

It will disable because as soon as you click the button, the treeviewnode loses focus and therefore disables. Could you not have the button in the treeview? — Ben Steele
Yes exactly. If I place the button inside the treeview, wouldn't the button hide the items behind it? — speccaN
Not if you make the button a child of the parent. It should expand like another other node meaning everything will shift down — Ben Steele
I never even realized you could do that. Thank you! That basically opens up a new world for me here! — speccaN
WPF can be quite the learning curve my friend :) We have all been where you are at some point — Ben Steele

Ben Steele Ben Steele · Accepted Answer · 2016-11-01T14:28:22

You could add the Button the treeview as a child like the following:

<Window x:Class="TreeDemo.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:local="clr-namespace:TreeDemo"
    mc:Ignorable="d"
    Title="MainWindow" Height="350" Width="525">
<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="172*"/>
        <ColumnDefinition Width="345*"/>
    </Grid.ColumnDefinitions>
    <TreeView>
        <TreeViewItem Header="Item 1">
            <Label Content="Invoce 1"/>
            <Button Content="Test 1" />
        </TreeViewItem>
        <TreeViewItem Header="Item 2">
            <Label Content="Invoce 2"/>
            <Button Content="Test2" />
        </TreeViewItem>
        <TreeViewItem Header="Item 3">
            <Label Content="Invoce 3"/>
            <Button Content="Test 3" />
        </TreeViewItem>
        <TreeViewItem Header="Item 3">
            <Label Content="Invoce 3"/>
            <Button Content="Test 3" />
        </TreeViewItem>
        <TreeViewItem Header="Item 3">
            <Label Content="Invoce 3"/>
            <Button Content="Test 3" />
        </TreeViewItem>
    </TreeView>
</Grid>

TreeView on Focus Leave - disable button

1 Answers