I have a LongListSelector and use binding.
When the user selects an Item in LongListSelector, I handle the SelectionChanged event of it and access it this way:
var selectedItem = MyListSelector.SelectedItem as NumbersViewModel;
But I want to change background color of that StackPanel which this selected item is inside it and add a TextBlock beside it:
<phone:LongListSelector.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
.
.
.
</StackPanel>
</DataTemplate>
</phone:LongListSelector.ItemTemplate>
How can I do this type of works on LongListSelector?
(It's a WP8 app)
You can bind the background of the stackpanel to a brush which can be added as a property in your NumbersViewModel. Also you can add the textblock inside the template and bind it's visibility to a boolean property inside your NumbersViewModel.
You can set the value of those properties in your selectionchanged event
Related
I have a Pivot control that uses an ItemsSource to bind to a list of ViewModel instances. I assign a custom ItemTemplateSelector to map between ViewModel types and DataTemplate definitions. This all works fine and the correct display is created for each ViewModel based on the associated DataTemplate. Something like this...
<Pivot ItemsSource="{x:Bind ViewModels}"
ItemTemplateSelector="{StaticResource ViewModelSelector}"
SelectedItem="{x:Bind SelectedViewModel, Mode=TwoWay}"/>
The problem is that I want to automatically set focus to a control within each page when that page is first shown. They are typically data entry forms and so the user currently has to select the first control to start entering data. It would be better if first showing a page automatically then set focus to a control on that page.
Any ideas?
You could bind a method to the TextBox when it's loaded.
For example:
<Pivot.ItemTemplate>
<DataTemplate x:DataType="local:Test">
<TextBox Text="{x:Bind Content}" Height="50" Loaded="{x:Bind TextBox_Loaded}">
</TextBox>
</DataTemplate>
</Pivot.ItemTemplate>
public void TextBox_Loaded(object sender, RoutedEventArgs e)
{
TextBox textBox = sender as TextBox;
if (textBox != null)
{
textBox.Focus(FocusState.Programmatic);
}
}
I am building a simple application that mainly consists of a TabControl and a StatusBar with an Slider. Each tab hosts an custom control that can be zoomed in & out. The slider in the status bar should give the user the abillity to zoom in & out the content of the currently selected tab. My problem is that I'am unable to assign the sliders value to the currently selected custom control.
Here's the xaml of my TabControl:
<TabControl x:Name="MyTabControl" ItemsSource="{Binding MyItems}">
<TabControl.ContentTemplate>
<DataTemplate>
<controls:MyControl x:Name="foo" DataContext="{Binding}">
</controls:MyControl>
</DataTemplate>
</TabControl.ContentTemplate>
</TabControl>
For the slider I want something like this, but it should be bound to the "foo.bar" property of the currently selected tab:
<Slider
Value="{Binding ElementName=foo, Path=bar}">
</Slider>
Is that possible or is there a better way to use a Slider to adjust and display a property of the currently selected custom control?
You can try adding a Value property to the class (or classes) that are set as the DataContext for each TabItem. Then you could data bind the Slider.Value property to the Value property in the data item from the selected TabItem using the TabControl.SelectedItem property. Try this:
<Slider Value="{Binding Path=SelectedItem.Value, ElementName=MyTabControl}" />
I have a custom control ListItem. I need to display five such items in a window and these items could change during runtime; items could be added or deleted, or content could change in ListItem.
ListBox appears to be a good solution to display items. But what I have seen is we can add items and style them, and can handle updates with data trigger.
myListBox.Items.Add(new { FileName = "SomeFile", State="Uploaded" });
But we can not do something like
ListItem curItem = new ListItem();
myListBox.Items.Add(new { curItem });
Even if I do it shows empty item in the list.
So if I want to add my custom control to some listbox, how could that be possible. That is using ListBox just as a container so we can get away from the pain of positioning and all that after list changes. Or is there a better way to do that?
You are in luck - this is the bread and butter of WPF! Set the ItemsSource of your ListBox (possible in XAML or cs):
myListBox.ItemsSource = myEnumerableCollection;
or
<ListBox ItemsSource="{Binding MyItemsProperty}">
Use a DataTemplate (you do not need a UserControl) to style each item in XAML:
<ListBox ItemsSource="{Binding MyItemsProperty}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Text="{Binding FileName}"/>
<TextBlock Text="{Binding State}"/>
<!--Whatever you want-->
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
If your collection is an ObservableCollection<T> changes to that collection (e.g. items added or removed) will be reflected in the ListBox automatically. If T implements INotifyPropertyChanged changes to properties on each item will also automatically show up on the UI.
For more see the WPF Binding Overview.
Don't create or manipulate UI elements in procedural code in WPF.
<ListBox ItemsSource="{Binding SomeCollection}">
<ListBox.ItemTemplate>
<DataTemplate>
<my:MyControl/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
where my:MyControl is a UserControl with whatever UI you want.
I have a ListBox bound to an ObservableCollection:
<ListBox ItemsSource="{Binding ObservableCollectionOfFoos}" />
The ObservableCollection contains instances of Foo, Foo implements INotifyPropertyChanged.
I'm trying to bind properties of the ListBoxItems to properties of Foo.
Here is what I tried:
<DataTemplate DataType="{x:Type local:Foo}" >
<TextBlock Content="{Binding PropertyOfFoo}" Background="{Binding AnotherPropertyOfFoo}"/>
</DataTemplate>
this works, but, the problem is that I only have access to the properties of the TextBlock and not the containing ListBoxItem, so, for example, Background only changes the color around the text and not the whole entry. I have a feeling I'm using the wrong tool for the job here.
a point in the right direction would be very appreciated.
The DataTemplate specifies the template (UI presentation) of the content of the list box item. What you need to style is the item container itself which can be done via the ItemContainerStyle property of the ListBox.
Basically, I have a list of colors and a defined datatemplate for listbox item:
<DataTemplate x:Key="colorItemDataTemplate">
<Border x:Name="borderInner" BorderBrush="Black" BorderThickness="1" Background="{Binding Brush}" Width="11" Height="11" />
</DataTemplate>
Now, when I add a bunch of items into the listbox and then set the ListBox.ItemsSource property to my List, the listbox is filled correctly.
There is also a slider with its appropriate event handler. Within the event handler, Brush property of one of the items from the listbox is changed. Since the appearance of the item depends on the Brush Property, listbox should reflect the change.
I could reset the ItemsSource property, but then all items have their templates applied and with more than 200 items in the listbox, this is pretty slow.
So, is there any way to refresh the template for only one item from the listbox?
Thanx
I'm not sure I follow. If you've bound the Background to the property, changing the property should automatically udpate the background of the ListBoxItem. If you're not seeing that, make sure you are either using a DependencyProperty or implementing INotifyPropertyChanged.
You could use a binding converter. In the converter class you could have some logic like
(pseudo-code)
if (ListBoxItem.IsSelected)
return SpecialColorFromSlider
else
return NormalListBoxColor