I am using ToolStripDropDown to create a autocomplete popup when user type in a textbox. I want the popup is only displayed at bottom right of the textbox.
But when the textbox's position is near the right or bottom edge of the screen, popup will display at other position.
Can anyone help me?
Code in derived class from ToolStripDropDown:
public void Show(Presenters.IMainView c, Point position)
{
base.Show(c as Control, position, ToolStripDropDownDirection.BelowRight);
}
Code in main view:
private void TextBoxAutocomplete_TextChanged(object sender, EventArgs e)
{
_mPopup.Show((IMainView)this, ((TextBox)sender).Location);
}
I want the popup behave like a normal form, which position is not restricted by screen or working area bounds, but not steal focus from parent form
I decided to use another and easier approach. Instead of using a derived class of ToolStripDropDown, I use a class derived from UserControl, make it not steal focus from it's parent (see this question)
Related
Im trying to add a UserControl in WPF to a grid, but it doesnt show up when im trying to add via MyGrid.Children.Add(UserControl). So i tried to display the number of childs of my grid and it says 1 after adding the usercontrol. (MyGrid.Children.Clear() doesn't work too. After clearing the grid it says that there are 0 childs left but there are still some UiElements when im compiling my program.)
This problem appears only in 1 function. In an other function (the same class) i can easily add childs to the same grid (myGrid).
My code:
private void AddDateOnClick(object sender, MouseButtonEventArgs e)
{
MyGrid.Children.Clear();
UserControlAddDate ucad = new UserControlAddDate();
MyGrid.Children.Add(ucad);
MessageBox.Show(MyGrid.Children.Count.ToString()); //Only to test if there are some childs
}
When i try to clear this grid in a other function (same class) it clears the grid. Only clearing in this function is a problem. Im not understanding why???
What is this UserControlAddDate? Maybe it is not initialized. That’s why it’s not getting added to the grid..
In that place try to add a textbox to the grid and check if it’s working. If it’s working then it’s the problem with your code.
As mentioned by Ed Plunkett, please try to use templates and databinding. It's the best way to work with WPF.
Try this anyway.
private void AddDateOnClick(object sender, MouseButtonEventArgs e)
{
MyGrid.Children.Clear();
TextBox ucad = new TextBox();
ucad.Text = “TEST”;
MyGrid.Children.Add(ucad);
MessageBox.Show(MyGrid.Children.Count.ToString()); //Only to test if there are some childs
}
I have an app that has a main window that contains a bunch of stuff. From time to time the user will do something in response to which I want to display something else entirely in the main window, temporarily hiding what is there.
I'm doing this by making the outermost element in the main window a Grid with no rows or columns defined. Every element in the grid, then will completely fill the one single cell in the grid, drawing on top of the others.
My regular bunch stuff, then, is in the first element of the grid, and my temporary something else is a UserControl as the second element of the grid, that is normally set Visibility=Collapsed.
Except for the KeyBinding everything works fine. When the appropriate command is triggered in the regular bunch of stuff, the visibility on the UserControl is set to Visible, and it covers the regular bunch of stuff completely. When the user clicks on the close button on the UserControl, it's visibility is set to Collapsed, again, and it disappears and the regular bunch of stuff is revealed.
My problem is with KeyBindings. I have a few defined on the UserControl - that should not be defined on the main window - and they don't work. Or rather, they work fine once I click inside the UserControl, but they don't work until I do.
I need them to work as soon as the UserControl is made visible, without requiring the user to click or tab into the UserControl proper.
My guess is that this has something to do with keyboard focus - but I've been unable to find a way to set the focus on the UserControl. Here's the thing - the only element within the UserControl is a tab control, all of the tabs of which are dynamically constructed via templates. There are no elements known at compile time that I can reference explicitly and pass to KeyBoard.Focus().
So, am I right in thinking that it's lack of focus that is causing the problem? And if so, how can I set focus to an element in a TabControl, when I don't even know how many tabs there are, let alone which is the selected one?
I wanted this control to have the focus, when it became visible. So in the constructor, I set up a handler on IsVisibleChanged.
public MyControl
{
...
this.IsVisibleChanged += new DependencyPropertyChangedEventHandler(MyControl_IsVisibileChanged);
}
void MyControl_IsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
{
if (!(bool(e.NewValue)
return;
this.Focusable = true;
Keyboard.Focus(this);
}
I could have set Focusable in the xaml, but I prefer it in the code-behind, so that all of the relevant code is in one place.
For me this worked in the code-behind:
using System.Windows.Input;
namespace MyApplication.Views.Dialogs
{
public partial class MyControl
{
public MyControl()
{
InitializeComponent();
Loaded += (sender, args) =>
{
MyButton.Focus();
Keyboard.Focus(MyButton);
};
}
}
}
I have an MVVM setup with a mainwindow that contains a ContentControl.
I set this to a particular viewmodel which then maps to a view.
A view is a usercontrol.
I want to be able to set the default keyboard focus to a default element in the usercontrol(View) when it loads so the application can eventually be driven just by using up, down, left, right and enter.
Some of my failed attempts are setting
FocusManager.FocusedElement="{Binding ElementName=DefaultElement}"
in my content control tag. This sets the logical focus but not the keyboard focus
I'd rather keep the solution in xaml if possable but have tried placing the following in code behind.
Keyboard.Focus(DefaultElement);
This does not work but if I popup a message box first it does. I'm a little confused as to why.
MessageBox.Show(Keyboard.FocusedElement.ToString());
Keyboard.Focus(DefaultElement);
EDIT::::
I just placed this in my onloaded event of my user control. It seems to work but can anyone see any issues that might arrise at this priority level. I.E a circumstance when the action will never run?
Dispatcher.BeginInvoke(
DispatcherPriority.ContextIdle,
new Action(delegate()
{
Keyboard.Focus(DefaultElement);
}));
It seems that this wpf the you have to implement a workaround on a case by case basis. The solution that seemed to work best, most of the time for me was to insert the focus code inside the dispatcher when OnVisible was changed. This sets the focus not only when the View/Usercontrol loads but also if you a changing Views by way of Visibility. If you Hide and then Show a ContentControl that is mapped to your ViewModels then the Loaded event won't fire and you'll be forced to Mouse input, or tabbing (Not so good if you want to navigate your app with a remote control).
VisibilityChanged will always fire however. This is what I ended up with for my listbox.
private void ItemsFlowListBox_IsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
{
if ((bool)e.NewValue == true)
{
Dispatcher.BeginInvoke(
DispatcherPriority.ContextIdle,
new Action(delegate()
{
ItemsFlowListBox.Focus();
ItemsFlowListBox.ScrollIntoView(ItemsFlowListBox.SelectedItem);
}));
}
}
I had the same symptom for a WPF UserControl hosted in a Winforms application. Just wanted to note I was about to try this solution when I found a normal TabIndex in the Winforms app fixed it
Per How to set which control gets the focus on application start
"The one with the minimum tab index automatically gets the focus
(assuming the TabStop property is set to true). Just set the tab
indices appropriately."
It's a tricky one with no easy answer. I'm currently doing this, although I'm not sure I like it:
public MyView()
{
InitializeComponent();
// When DataContext changes hook the txtName.TextChanged event so we can give it initial focus
DataContextChanged +=
(sender, args) =>
{
txtName.TextChanged += OnTxtNameOnTextChanged;
};
}
private void OnTxtNameOnTextChanged(object o, TextChangedEventArgs eventArgs)
{
// Setting focus will select all text in the TextBox due to the global class handler on TextBox
txtName.Focus();
// Now unhook the event handler, since it's no longer required
txtName.TextChanged -= OnTxtNameOnTextChanged;
}
And in case you're wondering what the global class handler does, it's this:
protected override void OnStartup(StartupEventArgs e)
{
...
// Register a global handler for this app-domain to select all text in a textBox when
// the textBox receives keyboard focus.
EventManager.RegisterClassHandler(
typeof (TextBox), UIElement.GotKeyboardFocusEvent,
new RoutedEventHandler((sender, args) => ((TextBox) sender).SelectAll()));
which auto selects TextBox text when receiving keyboard focus.
I'm trying to design a Popup which will appear on the bottom-right corner of its PlacementTarget
Let's admit that you set its PlacementTarget to a Window, well, the Popup will act as classic toaster notifications.
Given the fact that WPF is not smart enough to provide us a "corner" solution, I'm trying to implement a new control, inheriting from Popup , which will place itself at the appropriate location.
Here is my first idea: work on Loaded event to determine where should I place the Popup.
Problem? I don't want to give any fixed dimensions to the popup, which is supposed to size itself according to the text displayed.
However, I can't get the ActualWidth property when Loaded event is raised.
I can't have it either when Opened event is raised.
Here is the draft code so far:
public class ExceptionPopup : Popup
{
public ExceptionPopup()
{
InitializeComponent();
Loaded += new RoutedEventHandler(ExceptionPopup_Loaded);
}
void ExceptionPopup_Loaded(object sender, RoutedEventArgs e)
{
if (PlacementTarget != null)
{
if (PlacementTarget is FrameworkElement)
{
parentWidth = (PlacementTarget as FrameworkElement).ActualWidth;
parentHeight = (PlacementTarget as FrameworkElement).ActualHeight;
}
}
}
protected override void OnOpened(EventArgs e)
{
this.HorizontalOffset = parentWidth;
this.VerticalOffset = parentHeight;
base.OnOpened(e);
}
}
Is there any other event I could use to catch what I want here?
I'd basically like to set HorizontalOffset to parentWidth - ActualWidth/2 , same for height :)
Any idea?
Thanks!
Usually I set the PlacementTarget to either Bottom or Right, then apply a RenderTransform which shifts the Popup by the remaining value.
For example, I might use Placement=Bottom, then use a RenderTransform to shift the popup (Window.Width - Popup.Width) to the right, and Popup.Height upwards. You might not even need to re-adjust based on the Popup Height/Width becauase MSDN says that Popups are not allowed to be displayed off screen, and it will automatically adjust their placement to keep them visible
Be sure you use a RenderTransform instead of a LayoutTransform, because RenderTransforms get applied after the Popup gets Rendered, so the ActualHeight and ActualWidth will be greater than 0.
I am experiencing some very strange mouse-event behaviour when working with Silverlights DataGrid:
What I want to do is simply call some method when the user left-clicks over my DataGrid. That shouldn't be much a problem, but ...
With
public void doLeftClick (object sender, MouseButtonEventArgs e) {
// some code
}
i am defining the EventHandler and with
myDataGrid.MouseLeftButtonDown += doLeftClick;
i am attaching it to the event.
The result of that is that the doLeftClick method only gets called when i left-click over one of the columns of my DataGrid!
When i am doing the exact same code as above only for the right-click instead of the left-click the EventHandler gets called everytime i right-click over my DataGrid regardless where the mouse cursor is, as long it is inside the boundaries of the control (which is what i actually need with the left-click and what's the behavior i would expect from this setting):
public void doRightClick (object sender, MouseButtonEventArgs e) {
// some code
}
myDatagrid.MouseRightButtonDown += doRightClick;
So what am i doing wrong ? What am i forgetting ?
I really would appreciate any help :)
Marc
The click events are not bubbled up. If a child control marks the event as handled it stops.
In this instance the left click is being eaten by the DataGrid cells (in order to select them and/or give focus to edit controls).
Right click is not used by the cells in the same way, so propagates up to the DataGrid control.
The column headers are nice enough to allow the left click to propagate.