I'm trying to have a WPF ViewBox 'appearing' at the cursor position in a user control when the user right-clicks on the control. Right now, I have the code:
<!-- XAML -->
<Viewbox Width="100" Visibility="Collapsed" x:Name="actionBox">
<StackPanel Orientation="Horizontal" HorizontalAlignment="Stretch">
<Button>Item ▼</Button>
<Button>Permute ▼</Button>
<Button>Generate ▼</Button>
</StackPanel>
</Viewbox>
and
/* C# */
private void setPanel_MouseRightButtonDown(object sender, MouseButtonEventArgs e)
{
Point p = e.GetPosition(this);
actionBox.Margin = new Thickness(p.X, p.Y, 0, 0);
actionBox.Visibility = System.Windows.Visibility.Visible;
actionBox.BringIntoView();
}
The event does get fired, but nothing seems to happen. (The MouseRightButtonDown="..." is in a different part of the XAML file.)
How would one go about writing this in WPF?
Have a look at the Context Menu.
<ContextMenu Name="cm" StaysOpen="true">
<MenuItem Header="Item ▼"/>
<MenuItem Header="Permute ▼"/>
<MenuItem Header="Generate ▼"/>
</ContextMenu>
You can even bind the commands with the menu items as well create submenus.
Fore more information:
http://www.a2zdotnet.com/View.aspx?id=92
Related
I have a TabControl that contains a TextBox per tab. I need to select a tab programmatically and then set the selection of the TextBox and set the focus to the TextBox.
My problem is, when I first select a new tab in code and then set the focus to the textbox it doesn't work.
When the desired tab is already the selected tab and I set the focus to the textbox inside the tab, it's working.
It seems, that performing several actions on WPF elements does not work.
What is the right way to first switch the tab of a tabcontrol and then set the focus to a child in the newly selected TabItem?
Edit: I've found something on the Internet: Waiting for the render thread to complete:
https://social.msdn.microsoft.com/Forums/vstudio/en-US/693fbedb-efa6-413e-ab66-530c6961d3fb/how-to-wait-for-the-wpf-render-thread-to-catch-up?forum=wpf
Dispatcher.BeginInvoke(DispatcherPriority.ApplicationIdle, new Action(() => { })).Wait();
But is this the right way?
BTW: What is the difference between:
Dispatcher.BeginInvoke(DispatcherPriority.ApplicationIdle, new Action(() => { })).Wait();
Dispatcher.Invoke(DispatcherPriority.ApplicationIdle, new Action(() => { }));
Use the FocusManager.SetFocusedElement() method.
Focus has some nuances, you can learn more here.
XAML
<TabControl>
<TabItem Header="One"
x:Name="tabOne">
<Button HorizontalAlignment="Center"
VerticalAlignment="Center"
Content="Set Focus"
Click="Button_Click" />
</TabItem>
<TabItem Header="Two"
Name="tabTwo">
<StackPanel>
<TextBox Name="txtOne" />
<TextBox Name="txtTwo" />
</StackPanel>
</TabItem>
<TabItem Header="Three"
x:Name="tabThree">
<StackPanel>
<TextBox Name="txtThree" />
<TextBox Name="txtFour" />
</StackPanel>
</TabItem>
</TabControl>
CODE
private void Button_Click(object sender, RoutedEventArgs e)
{
tabTwo.IsSelected = true;
FocusManager.SetFocusedElement(tabTwo, txtTwo);
}
I have been working with c# for some time now but surprisingly I have never dealt with context menus before. I have a listView control in my universal windows 8.1 app. Now I am trying to get a context menu to popup for each item in the listView (they are all the same type of object and are added to the list as the user adds entries). I have run into several problems with this and have looked at code examples and they seem to be leading in different directions. Firstly when I right click on an item in the list it does not fire the ListView_RightTapped event.
<ListView x:Name="lstvwHours" HorizontalAlignment="Left" Height="264" Margin="427,77,0,0" VerticalAlignment="Top" Width="357" RightTapped="lstvwHours_RightTapped">
Secondly in Microsoft's context menu code example they say to use the PopupMenu class but in other code I've seen it coded into the XAML.
And lastly After the one context menu button is clicked I want it to fire a delete method.
private async void lstvwHours_RightTapped(object sender,
RightTappedRoutedEventArgs e)
{
var menu = new PopupMenu();
menu.Commands.Add(new UICommand("Delete"/*do I put the method to call here?*/));
var chosenCommand = await menu.ShowForSelectionAsync(GetElementRect((FrameworkElement)sender));
}
Here's an example.
In this case you can wire-up the commands that get invoked from your menuitem onto your view-model.
<ListView>
<ListViewItem Content="One">
<ListViewItem.ContextMenu>
<ContextMenu>
<MenuItem Header="Insert"
Command="{Binding DataContext.InsertQuery, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=ContextMenu}}"/>
<MenuItem Header="Delete"
Command="{Binding DataContext.DeleteQuery, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=ContextMenu}}"/>
</ContextMenu>
</ListViewItem.ContextMenu>
</ListViewItem>
</ListView>
I have a really strange behaviour, and I hope someone can help me out.
I have the following XAML layout:
<StackPanel Orientation="Horizontal">
<Menu>
<Menu.Items>
<MenuItem Padding="2,0,2,0">
<MenuItem.Header>
<Button Content="Details"
Click="Details_Click" />
</MenuItem.Header>
</MenuItem>
</Menu.Items>
</Menu>
<Button Content="Details"
Click="Details_Click" />
</StackPanel>
Please notice that both buttons have the same Event registered.
The Details_Click Event looks like this:
private void Details_Click(object sender, RoutedEventArgs e)
{
var viewer = new DictionaryViewer();
viewer.ShowActivated = true;
viewer.Show();
viewer.Topmost = true;
viewer.Topmost = false;
viewer.Activate();
viewer.Focus();
e.Handled = true;
return;
}
Now I am facing the problem, even with all the code from above the Window doesnt show up activated when I press the button inside the Menu but outside of it works with just .Activate();.
(How I know that window isnt activated: need 2 clicks to close/minimize/maximize it)
Why would my XAML Layout ruin the Activation of the DictionaryViewer(); window, with the button inside Menu?
(To your information the DictionaryViewer is totally empty, its a fresh window nothing implemented yet)
Edit:
Yes, I know there is the MenuItem_Click Event that may make it work, but I need/want the button inside the Menu how can I fix this issue?
THe reason this is happening is because the Button inside the MenuItem is gaining Focus after the Window has opened.
If you set the Focusable property of the button inside MenuItem, this fixes the issue.
E.g.
<StackPanel Orientation="Horizontal">
<Menu>
<Menu.Items>
<MenuItem Padding="2,0,2,0">
<MenuItem.Header>
<Button Content="Details"
Click="Details_Click"
Focusable="False" />
</MenuItem.Header>
</MenuItem>
</Menu.Items>
</Menu>
<Button Content="Details"
Click="Details_Click" />
</StackPanel>
I have an Ellipse in my WPF application. I want to change the colour of its outline whenever it is double clicked. I found this (old) tutorial about making this work by using the available MouseDown event and checking for a ClickCount of two in the event handler. This is the simplest solution to my problem and I'd like to try and get this to work before creating an empty button Control Template.
However, I'm unable to find the clicked ellipse in my code behind file. Supposedly this works in the tutorial, but I'm wondering if I'm missing anything.
Here's the code that contains the ellipse. It is the 3rd column of a grid:
<ScrollViewer VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto" Grid.Column="3">
<StackPanel Orientation="Vertical" Margin="3,1" Background="GhostWhite">
<ItemsControl Name="FlowLinkItems" ItemsSource="{Binding FlowLinkList}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Grid Height="40">
<Ellipse Name="FlowLinkEllipse" Stroke="BlueViolet" Height="38" VerticalAlignment="Center" MouseDown="Ellipse_MouseDown"/>
<TextBlock TextAlignment="Center" HorizontalAlignment="Center" VerticalAlignment="Center" Text="{Binding Message}"></TextBlock>
</Grid>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</StackPanel>
</ScrollViewer>
In the tutorial, the code behind method worked like this:
private void Ellipse_MouseDown(object sender, MouseButtonEventArgs e)
{
if (e.ClickCount == 2)
{
FlowLinkEllipse.Stroke = "Red";
}
}
And the error I'm seeing is:
The name 'FlowLinkEllipse' does not exist in the current context
If this method is not possible I'm open to suggestions that are as simple as possible (I'm still new to WPF and the only thing my app will handle is this double click).
Note: I do have this line in my code behind and it works fine.
FlowLinkItems.MouseLeftButtonUp += FlowLinkItems_MouseLeftButtonUp;
As #Magus noted, you can't reference an item from code-behind, that is inside a DataTemplate. That should be no problem here, though: sender will contain a reference to the ellipse:
private void Ellipse_MouseDown(object sender, MouseButtonEventArgs e)
{
if (ellipse as sender == null || e.ClickCount < 2)
return;
var ellipse = (Ellipse)sender;
ellipse.Stroke = System.Windows.Media.Brushes.Red;
}
how can I access the arrow buttons on the ends of scrollbars in silverlight? Are they button controls which can be accessesed through thescrollbar class or something else?
The reason I need to know this is so that when someone click on either of the arrow buttons I can run some custom functionality to the scrollbar
If you need to know what button of the scrollbar was clicked you can could access that via the ValueChanged property of the ScrollBar
For instance I've got a simple scroll bar with a textblock and on each click, the textblock displays which button was clicked.
<Grid x:Name="LayoutRoot" Background="White">
<ScrollBar Height="200" Orientation="Vertical" Width="20" ValueChanged="ScrollBar_ValueChanged" />
<TextBlock Height="23" HorizontalAlignment="Left" Margin="150,21,0,0" Name="textBlock1" Text="" Width="100" VerticalAlignment="Top" />
</Grid>
and the code behind would be
private void ScrollBar_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
{
if (e.NewValue > e.OldValue)
textBlock1.Text = "Down Arrow Clicked";
else
textBlock1.Text = "Up Arrow Clicked";
}
Solved this problem like so:
foreach( var o in horizontalBar.GetVisualDescendants( ) )
{
if(o is RepeatButton)
{
//set call back based on the name of the repeatbutton
}
}