Develop Reference

Popup with "StaysOpen=false" steals LeftMouseButtonDown event

In my application, when a user attempts to click a slider which is on the main window, while a popup control is open, the popup control steals the mouse down event.
This results in the slider not responding to the mouse down event correctly.
(it seems to get focus and move to an incorrect location)
I found that the that the "OnPreviewMouseLeftButtonDown" in the slider does not fire when popup's "StaysOpen" property is false (and the popup is open),
and does fire when its true (or when the popup is closed).
I was wondering if someone has found a solution for this issue.
I encountered these type of issues in other controls in my application in various contexts, So I would prefer a more general solution rather than just solving this for the slider.
Sample code:
<Window x:Class="SampleApplication.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
x:Name="Root"
Title="MainWindow" Height="350" Width="525">
<Grid Height="130" Width="300">
<Button Width="40" Height="40" Click="ButtonBase_OnClick" HorizontalAlignment="Left" VerticalAlignment="Top"></Button>
<Popup StaysOpen="False" IsOpen="{Binding ElementName=Root, Path=IsOpen}" Width="100" Height="100"
HorizontalAlignment="Center" VerticalAlignment="Center" Placement="Center">
<Grid Background="Black">
<TextBlock Text="hello"></TextBlock>
</Grid>
</Popup>
<Slider Width="200" IsMoveToPointEnabled="True" VerticalAlignment="Bottom"></Slider>
</Grid>
Thanks ahead,
Yotam

This happens because PreviewMouseDown (and it's derivates) (from the base class UIElement) has a default RoutingStrategy.Direct.
Direct - The routed event does not route through an element tree, but does support other routed event capabilities such as class handling, EventTrigger or EventSetter.
This is the source code of the event taken from ReferenceSource.
public static readonly RoutedEvent PreviewMouseLeftButtonDownEvent =
EventManager.RegisterRoutedEvent(
"PreviewMouseLeftButtonDown",
RoutingStrategy.Direct,
typeof(MouseButtonEventHandler),
_typeofThis);
And here is what happens in the Popup:
private void OnPreviewMouseButton(MouseButtonEventArgs e)
{
// We should only react to mouse buttons if we are in an auto close mode (where we have capture)
if (_cacheValid[(int)CacheBits.CaptureEngaged] && !StaysOpen)
{
Debug.Assert( Mouse.Captured == _popupRoot.Value, "_cacheValid[(int)CacheBits.CaptureEngaged] == true but Mouse.Captured != _popupRoot");
// If we got a mouse press/release and the mouse isn't on the popup (popup root), dismiss.
// When captured to subtree, source will be the captured element for events outside the popup.
if (_popupRoot.Value != null && e.OriginalSource == _popupRoot.Value)
{
// When we have capture we will get all mouse button up/down messages.
// We should close if the press was outside. The MouseButtonEventArgs don't tell whether we get this
// message because we have capture or if it was legit, so we have to do a hit test.
if (_popupRoot.Value.InputHitTest(e.GetPosition(_popupRoot.Value)) == null)
{
// The hit test didn't find any element; that means the click happened outside the popup.
SetCurrentValueInternal(IsOpenProperty, BooleanBoxes.FalseBox);
}
}
}
}
So it was designed to work this way, and you should likely not use OnPreviewMouseDown for whatever you are trying to accomplish here.

In my application, when a user attempts to click a slider which is on the main window, while a popup control is open, the popup control steals the mouse down event
While your description is not completely correct, that is the normal behaviour of any Popup control. The reason that this occurs is because the Popup control has focus and so it is listening out for the Click event even if it occurs outside the bounds of the Popup. Think about this logically now... if it didn't do this, how would it know when to close? You will find the same behaviour from the Popup control used in a ComboBox.

There is a workaround to achieve the behavior you require, Set 'IsHitTestVisible = True' for the Slider control you are use.
PS:
Set IsHitTestVisible = True, only when the Popup is Open - False otherwise.

How to receive focus when clicking on the background of a stackpanel?

I have a UserControl which contains a Label and a TextBox. Both are placed inside a stackpanel which is placed in a border.
I now want to receive an Event when the mouse clicks somewere inside the stackpanel or the border. I tried several things, as using transparent Backgrounds, different Events like ismousedirectlyover etc.
Is there a way i can solve this?

You can try by capturing the mousedown event inside your textbox, your label and your stackpanel and bind them all directly to the same method, you will allways get the mousedown event independent on where you clicked.
You can also try to set the
Panel.Zindex
property to a higher number in the stackpanel and then only capture the mousedown event on it.

1) Add an handler for the MouseLeftButtonDown to the border:
<Border MouseLeftButtonDown="Border_MouseLeftButtonDown">
<StackPanel Background="Transparent">
<TextBox x:Name="Text" />
</StackPanel>
</Border>
2) Set the focus manually to the TextBox:
private void Border_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
Text.Focus();
}
make sure to set the background of the stackpanel to transparent.

In Windows phone,How to change checkbox state after questioning user?

In my app,there is a need to do this
At start,the checkbox is unchecked
user tap,and then pop up a messagebox as a alarm to make sure user indeed want to do it(At the moment the checkmark is still collapse)
If user click "Yes,I want to do it",then checkmark is visible and now it is checked
vice versa
I found that,when I tap the checkbox,Checked event is always triggering
and
the checkmark is always turn to "checked" state
How to solve the problem???
Any advice would be great,Thanks!!!

Just a trick is needed. Sharing a sample with you.
overlap a transparent background grid over your checkbox with a transparent background like this.
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
<StackPanel>
<Grid>
<CheckBox Name="cb" Content="cb" Checked="CheckBox_Checked_1"/>
<!--Grid that overlaps the checkbox-->
<Grid Background="Transparent" Tap="Grid_Tap_1"/>
</Grid>
</StackPanel>
</Grid>
This overlapping wont call any checkbox event even if you tap on it
now in code of the event
private void Grid_Tap_1(object sender, GestureEventArgs e)
{
if(MessageBox.Show("Message")==MessageBoxResult.Ok)
{
cb.IsChecked=True;
}
}

Instead of Tap Event, Try Checked and Unchecked Events of the checkbox.
Note: You can track the checked status in "Checked" and "UnChecked" events of the Check Box using IsChecked Property and write your code in appropriate events.
After Asking confirmation to user.
If the user clicks "Yes" , set chkBox.IsChecked=true;
else
If the user clicks "No", set chkBox.IsChecked=false;

I think there is no way to stop checkbox default behaviors. So you can create a custom control with a image and a textbolck inside a stack panel. You should use pair of images for "Image" Control Source one for unchecked and another for checked.
//At start,the checkbox is unchecked
<StackPanel x:Name="panelCheckBox" Tap="panelCheckBox_Tap_1" Orientation="Horizontal">
<Image Source="UncheckImageSourc" x:Name="ImgeCheckBox"/>
<TextBlock Text="CheckBox Content"/>
</StackPanel>
In Code Behind
bool IsChecked=false;
private void panelCheckBox_Tap_1(object sender, System.Windows.Input.GestureEventArgs e)
{
//If user click "Yes,I want to do it",then checkmark is visible and now it is checked
if(!IsChecked)
{
IsChecked =true;
ImgeCheckBox.Source = "CheckImageSource";
}
else
{
IsChecked =false;
ImgeCheckBox.Source = "UncheckImageSourc";
}
}

Silverlight RadComboBox Dropdown stays open even when not in focus

I have a user control that contains a scroll viewer. inside the scroll viewer I placed another user control with grid, and inside the grid there is a combo box.
all this is placed inside a RadWindow.
Something like this:
first user control: (displayed inside a RadWindow)
<UserControl x:class = "MyFirstUserControl">
<Grid>
<ScrollViewer>
<StackPanel x:Name="stackPanel"/>
</ScrollViewer>
</Grid>
</UserControl>
second user control:
<UserControl x:class = "MySecondUserControl">
<Grid>
<telerik:RadComboBox x:Name = "comboBox"/>
</Grid>
</UserControl>
in code behind I add the second user control to the stackPanel:
stackPanel.Children.Add(new MySecondUserControl());
Now, the problem is: when the combo-box drop down is open, and I scroll up / down the control - I expect it to close, but- it remains open...
I try to catch the MouseLeftButtonUp event of the scroll bar, and set the IsDropDownOpen of the comboBox to false, but it is false nonetheless and the drop-down still open.
How can I force the drop-down to close when focus is not on it, even if the focus is out of the combo control altogether?
Thanks,

WinRT Controls Over Scrollviewer Consuming Scrolling

My issue is that I have a few controls (buttons, combo-boxes, hit test visible controls, etc) that are on top of a scrollviewer. Now there is no reason for these controls to consume a pointer wheel changed event, and in checking so they do not. But it seems that when the pointer is over these controls and I attempt to scroll, the scrolling event does not get fired on the scrollviewer (I believe that actual event that is supposed to fire is ViewChanged). Now the buttons and stuff should still handle their regular events, such as PointerPressed, KeyDown, etc. But I want to stop them from consuming the event that would cause the scrollviewer to scroll. Any ideas? Thanks in advance.
This is a quick example of what I'm dealing with:
<Grid>
<ScrollViewer>
<StackPanel>
<!-- Insert any number of things here -->
</StackPanel>
</ScrollViewer>
<Button>Hello World</Button>
</Grid>

Add an event to the controls:
public void UIElement_PointerWheelChanged(object sender, PointerWheelChangedEventArgs e)
{
e.Handled = false;
}