WPF - Remove a "User Control" Child from a StackPanel - c#

I'm trying to make a WPF UI where the user can edit a query to search the database. The query is created according to what the consumer chooses from the comboboxes Like This and he can create as much filters as he wants as long as he clicks the Add new Condition button.
I created the comboboxes template as a User Control like this :
User control XAML:
<StackPanel Orientation="Horizontal" >
<Button
Name="DeleteFilter"
HorizontalAlignment="Left"
Margin="5"
Content="-"
Click="DeleteFilter_OnClick">
</Button>
<ComboBox
Text="Property"
x:Name="Property"
Width="100"
DataContext="{StaticResource SomeViewModel}"
ItemsSource="{Binding Properties}"
DisplayMemberPath="Name"
SelectionChanged="Property_OnSelectionChanged"/>
<ComboBox
Text="PropertyOperator"
x:Name="Operator"
ItemsSource="{Binding Operators}"
DisplayMemberPath="Name"
SelectionChanged="Operator_OnSelectionChanged">
</ComboBox>
<TextBox
x:Name="Value"
Text="Value"
TextAlignment="Center"
Width="100"
Margin="5"/>
</StackPanel>
Whenever the user clicks the Add new Condition button, I call this event:
private void AddFilterButton_OnClick(object sender, RoutedEventArgs e)
{
var conditionUserControl = new ConditionUserControl();
StackPanel.Children.Add(conditionUserControl);
}
Everything works correctly.
My Question:
How can I delete the User Control child from clicking the DeleteFilter button that exists in the User Control template.
I tried this:
StackPanel.Children.Remove(..);
to remove the child from my MainWindow but how to know which child the user clicked.

Try this:
private void DeleteFilter_OnClick(object sender, RoutedEventArgs e)
{
Button btn = sender as Button;
var conditionUserControl = FindParent<ConditionUserControl>(btn);
if (conditionUserControl != null)
{
var sp = FindParent<StackPanel>(conditionUserControl);
if (sp != null)
sp.Children.Remove(conditionUserControl);
}
}
private static T FindParent<T>(DependencyObject dependencyObject) where T : DependencyObject
{
var parent = VisualTreeHelper.GetParent(dependencyObject);
if (parent == null) return null;
var parentT = parent as T;
return parentT ?? FindParent<T>(parent);
}

Another answer to #mm8 answer is :
Update the AddFilterButton_OnClick:
I did this and the functionality works:
private void AddAndFilterButton_OnClick(object sender, RoutedEventArgs e)
{
var conditionUserControl = new ConditionUserControl();
StackPanel.Children.Add(conditionUserControl);
conditionUserControl.DeleteFilter.Click += (o, args) => StackPanel.Children.Remove(conditionUserControl);
}

Related

Get names of control in code behind when clicked, wpf

I have a usercontrol and I want to get the names of the control user clicks on this usercontrol.
The Usercontrol xaml is given below:
<Grid Name="Grid1">
<ListView Name ="ListView1">
<listbox.resources>
<Datatemplate>
<Togglebutton Name="Button1">
</Togglebutton>
</Datatemplate>
</listbox.resources>
</Listview>
<Border Name="Border1">
<ContentControl>
</ContentControl>
</Border>
</Grid>
Now in my code behind, I wrote:
this.PreviewMouseLeftButtonDown += new MouseButtonEventHandler(mouseclicked);
private void mouseclicked(object sender, MouseButtonEventArgs e)
{
var source = e?.OriginalSource as FrameworkElement;
if (source != null)
{
var parent = source.Parent as FrameworkElement;
string name = string.Empty;
if (parent != null)
{
name = parent.Name;
}
else
{
name = source.Name;
}
//If clicked outside the usercontrol, then usercontrol should close down
if (!(name.Contains("Border1") || name.Contains("Grid1"))) //very strange values sometimes null or empty
{
//then do something
}
}
}
How can I get the names of the controls used in my Usercontrol in codebehind?
You have gave the grid, border and listview a name in XAML. This you should access in codebehind and check in the mouseclicked event, which element is mouse over.
private void mouseclicked(object sender, MouseButtonEventArgs e)
{
if (ListView1.IsMouseOver && Grid1.IsMouseOver)
{
MessageBox.Show("List view clicked");
}
if (Border1.IsMouseOver && Grid1.IsMouseOver)
{
MessageBox.Show("Border1 clicked");
}
if (Grid1.IsMouseOver)
{
MessageBox.Show("Grid1 clicked");
}
}
This would may be not the best, but could work to get the names of controls the user has clicked.

Access Datacontext from binded user control

I have build a dynamic UserControl from an ObservableCollection as follows...
public static ObservableCollection<Model.Model.ControleData> ListControleMachine = new ObservableCollection<Model.Model.ControleData>();
public Genkai(string Autorisation) {
InitializeComponent();
DataContext = this;
icTodoList.ItemsSource = ListControleMachine;
Model.Model.ControleData v = new Model.Model.ControleData();
v.ComputerName = "M57095";
v.ImportSource = "LOAD";
ListControleMachine.Add(v);
}
XAML
<ItemsControl x:Name="icTodoList" ItemsSource="{Binding ListControleMachine}" >
<ItemsControl.ItemTemplate>
<DataTemplate DataType="{x:Type local:ControlMachineII}">
<local:ControlMachineII />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
But how can I access the DataContext from C# code?
For example say I want to delete the UserControl with a close button in itself, I need at least access ControleData.ComputerName value then remove it from Mainform.ListControleMachine.
I can't find the best practice for achieve this and play with my data in UserControl code.
The remove button code is like this i think (with hard coded value)
Genkai.ListControleMachine.Remove(Genkai.ListControleMachine.Where(X => X.ComputerName == "M57095").Single());
i finaly found that my DataContext was not yet initialized at start that why i got error so i had to wait for the datacontext first: here code for correction
public ControlMachineII()
{
InitializeComponent();
DataContextChanged += new DependencyPropertyChangedEventHandler(ControlMachineII_DataContextChanged);
}
private void ControlMachineII_DataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
{
string compname = (this.DataContext as Model.Model.ControleData).ComputerName;
Console.WriteLine("DataContext initialized computername :" +compname);
}
I saw you posted same question today with some more data. I'm going to present the solution using that data.
Solution 1 :
Use Tag property of button like below:
<Button Content="Close this UC" HorizontalAlignment="Left" Margin="414,22,0,0"
VerticalAlignment="Top" Width="119" Click="Button_Click" Tag="{Binding RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}" />
Event handler:
private void Button_Click(object sender, RoutedEventArgs e)
{
var button = sender as Button;
List<object> list = (button.Tag as ItemsControl).ItemsSource.OfType<TodoItem>().ToList<object>();
list.Remove(button.DataContext);
(button.Tag as ItemsControl).ItemsSource = list;
}
Solution 2:
More elegant solution:
Create this Style in your MainWindow:
<Window.Resources>
<Style TargetType="Button">
<EventSetter Event="Click" Handler="Button_Click"/>
</Style>
</Window.Resources>
So now the Handler of any Button Click event in any MainWindow's descendant Button Control is in the MainWindow.xaml.cs.
Then place the handler method in MainWindow.xaml.cs and change the handler like below:
private void Button_Click(object sender, RoutedEventArgs e)
{
var button = sender as Button;
items.Remove(button.DataContext as TodoItem);
icTodoList.ItemsSource = null;
icTodoList.ItemsSource = items;
}

Bound ItemsControl not updating before displaying

I have a UserControl that is comprised of a few bound ItemsControl's and strings, and based on the button that is pressed, different data is displayed. Here is an example of one of the Button's click events:
private void LeftPreviousScoresButton_Click(object sender, RoutedEventArgs e)
{
if (m_previousScoresWindow.Visibility == Visibility.Visible)
{
m_previousScoresWindow.Hide();
}
else
{
WindowTitle = "Left Side";
PreviousScoresA = m_previousLeftWristErosionScoresReaderA;
PreviousScoresB = m_previousLeftWristErosionScoresReaderB;
m_previousScoresWindow.Show();
}
}
There are several of these click event listeners which assigns WindowTitle, PreviousScoresA, and PreviousScoresB with the associated data. The UserControl then binds to them like this:
<ItemsControl Height="Auto" Width="Auto"
ItemsSource="{Binding ElementName=ParentForm, Path=PreviousScoresA}"
Grid.Row="1" />
<ItemsControl Height="Auto" Width="Auto"
ItemsSource="{Binding ElementName=ParentForm, Path=PreviousScoresB}"
Grid.Row="2" />
<TextBlock FontSize="16" FontWeight="Bold" Height="25"
Margin="5" HorizontalAlignment="Center" Foreground="Black"
Text="{Binding ElementName=ParentForm, Path=PreviousScoresWindowTitle}" />
However, when opening the window, the old data displays for a second before it is updated with the current data. I've even tried adding these calls when calling Hide() on the Window but it didn't seem to help:
WindowTitle = String.Empty;
PreviousScoresA = new ObservableCollection<PreviousScoreData>();
PreviousScoresB = new ObservableCollection<PreviousScoreData>();
Is there any way to ensure that Show() is not called until after the bound data has been updated? Thanks.
As it appears you are using an ObservableCollection, the collection should never be re-initialized. Rather, it should just be cleared and then add the new values; this is what helps keep the collection synchronized when using an ObservableCollection.
This is a bit of a shot in the dark based on your code sample; if you clear the collection when hiding and then refill them with the new values, then you should get the desired effect:
private void LeftPreviousScoresButton_Click(object sender, RoutedEventArgs e)
{
if (m_previousScoresWindow.Visibility == Visibility.Visible)
{
m_previousScoresWindow.Hide();
WindowTitle = string.Empty;
PreviousScoresA.Clear();
PreviousScoresB.Clear();
}
else
{
WindowTitle = "Left Side";
// do not re-initialize the collection; clear and add new values
// PreviousScoresA = m_previousLeftWristErosionScoresReaderA;
// PreviousScoresB = m_previousLeftWristErosionScoresReaderB;
ReFillScores(PreviousScoresA, m_previousLeftWristErosionScoresReaderA);
ReFillScores(PreviousScoresB, m_previousLeftWristErosionScoresReaderB);
m_previousScoresWindow.Show();
}
}
private void ReFillScores (ObservableCollection<PreviousScoreData> collection, IEnumerable<PreviousScoreData> values)
{
collection.Clear();
foreach(PreviousScoreData d in values)
{
collection.Add(d);
}
}

Give focus to a component inside an expander

I have this requirement where I need to focus the first element inside the expander when the user press tab.
Currently (default behavior) the focus goes to the expander, I've tried to focus the first element of the expander by creating a focus event handler in the expander like this:
private void ExpanderGotFocus(object sender, RoutedEventArgs e)
{
var expander = (Expander) sender;
if (!expander.IsExpanded)
{
expander.IsExpanded = true;
this._someText.Focus();
}
}
Which doesn't work.
I've also tried to give the focus the the next element:
var tRequest = new TraversalRequest(FocusNavigationDirection.Next);
var keyboardFocus = Keyboard.FocusedElement as UIElement;
keyboardFocus.MoveFocus(tRequest);
But only works the second time ( when the expander has been at least opened once )
I've tried to put this in a thread and some other crazy ideas.
How can I give focus to the first element inside an expander? ( the first time the expander is closed )
I tried several ways and none of them worked, basically the problem is the TextBox is still rendering when the expander is expanding ( to early ).
So instead what I've found is to add the IsVisibleChanged event to the textbox so when the expander finished the textbox become visible and request the focus
XAML
<Expander GotFocus="ExpanderGotFocus">
<Expander.Header>
<TextBlock Text="{x:Static Client:Strings.XYZ}" />
</Expander.Header>
<Expander.Content>
<StackPanel>
<TextBox IsVisibleChanged="ControlIsVisibleChanged" Name="txtBox" />
</StackPanel>
</Expander.Content>
</Expander>
Code behind
private void ExpanderGotFocus(object sender, RoutedEventArgs e)
{
var expander = (Expander) sender;
if (!expander.IsExpanded )
{
expander.IsExpanded = true;
}
}
private void ControlIsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
{
Keyboard.Focus((IInputElement)sender);
}
Check with the following,
XAML code:
<StackPanel>
<Expander Header="Expander"
Name="expander"
Collapsed="OnCollapsed"
IsExpanded="True" >
<StackPanel>
<TextBox Text="Text1" Name="textBox1" />
<TextBox Text="Text2" Name="textBox2" />
<TextBox Text="Text3" Name="textBox3" />
</StackPanel>
</Expander>
<TextBox Text="Text4" Name="textBox4" />
</StackPanel>
in the code behind:
public partial class Window1 : Window
{
public Window1()
{
InitializeComponent();
this.Loaded += delegate
{
textBox2.Focus();
};
}
private void OnCollapsed(object sender, RoutedEventArgs e)
{
var element = Keyboard.FocusedElement;
if (element != null)
{
//now is the ToggleButton inside the Expander get keyboard focus
MessageBox.Show(element.GetType().ToString());
}
//move focus
Keyboard.Focus(textBox4);
}
}

WPF - How do determine the index of the current item in a listbox from button handler

i have a listbox with a data template that contains a button.
When the button is clicked I want to get in the button
click handler the index of the listbox item that was current??
How do I do this please?
Malcolm
More appropriate answer,
private void Button_Click(object sender, RoutedEventArgs e)
{
DependencyObject dep = (DependencyObject)e.OriginalSource;
while ((dep != null) && !(dep is ListViewItem))
{
dep = VisualTreeHelper.GetParent(dep);
}
if (dep == null)
return;
int index = lstBox.ItemContainerGenerator.IndexFromContainer(dep);
}
Hope the bellow code will help you.
private void Button_Click(object sender, RoutedEventArgs e)
{
var b = (Button)sender;
var grid = (Grid)b.TemplatedParent
var lstItem = (ListBoxItem)grid.TemplatedParent;
int index = lstBox.ItemContainerGenerator.IndexFromContainer(lstItem);
// rest of your code here...
}
And the XAML for the above assumed to be a DataTemplate on a ListBox named lstBox:
<DataTemplate x:Key="template">
<Grid>
<Button Click="Button_Click" Content="Press"/>
</Grid>
</DataTemplate>
Have you checked the "SelectedIndex" property of the listbox? It might be set by clicking on the button.
Probably way to late but using "IndexOf" on the listbox "Items" will give you the index #
Regards
myListbox.Items.CurrentItem seems be what you are looking for.
Hi you can use ContentPresenter.Content to get current item , instead of current index:
<DataTemplate DataType="{x:Type MyModel}">
<StackPanel Orientation="Horizontal" Margin="0 5">
<TextBlock Text="{Binding Title}" />
<Button Content="Active" Click="Button_Click" />
</StackPanel>
</DataTemplate>
and in code:
private void Button_Click(object sender, RoutedEventArgs e)
{
var button = e.Source as Button;
var contentPresenter = button.TemplatedParent as ContentPresenter;
var myModel = (MyModel)contentPresenter.Content;
}

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