How to attach EventTrigger in code behind in Silverlight 4 - silverlight-4.0

My question is the following:
I have a grid and I attached the SelectedIndexChanged event the following way in the xaml file:
"<cc:DetailViewGrid AutoGenerateColumns="False" HorizontalAlignment="Stretch" Margin="0,0,0,0" Name="dgAcitivityList" VerticalAlignment="Stretch" ItemsSource="{Binding EntityList}" SelectionMode="Single" IsReadOnly="False">
<interactivity:Interaction.Triggers>
<interactivity:EventTrigger EventName="SelectionChanged">
<interactivity:InvokeCommandAction Command="{Binding SelectedItemChangeCommand}" CommandParameter="{Binding SelectedItem, ElementName=dgAcitivityList}"/>
</interactivity:EventTrigger>
</interactivity:Interaction.Triggers>"
But I want to attach this event in code behind. I ctreated an own grid that is inherited from windows grid, and I put this code to own control.
public override void OnApplyTemplate()
{
//base.OnApplyTemplate();
System.Windows.Interactivity.EventTrigger selectedItemChangedTrigger = new System.Windows.Interactivity.EventTrigger("SelectionChanged");
System.Windows.Interactivity.InvokeCommandAction action = new System.Windows.Interactivity.InvokeCommandAction();
action.CommandName = "{Binding SelectedItemChangeCommand}";
action.CommandParameter = string.Format("{{Binding SelectedItem, ElementName={0}}}", this.Name);
selectedItemChangedTrigger.Actions.Add(action);
System.Windows.Interactivity.Interaction.GetTriggers(this).Add(selectedItemChangedTrigger);
base.OnApplyTemplate();
}
Is this solution proper? It's not working but I'm not sure that I should put this code in the OnApplyTemplate() method.

Related

GroupBox control in UWP?

Getting acquainted with UWP. I'm developing an App for simulating electric circuits. There is a classic visual control called Frame, later called GroupBox in WPF.
It seems this control is absent in UWP.
There is a control called HeaderedContentControl in UWP.Toolkit library, but doesn't look the same. And seems the background and border properties don't work..
currently my code is:
<controls:HeaderedContentControl Margin="5"
BorderBrush="Black" BorderThickness="1"
HorizontalAlignment="Stretch"
HorizontalContentAlignment="Stretch">
<controls:HeaderedContentControl.Header>
<Border BorderBrush="Black" BorderThickness="1">
<Border.RenderTransform>
<TranslateTransform Y="-10"/>
</Border.RenderTransform>
<TextBlock Text="Resistor Value"/>
</Border>
</controls:HeaderedContentControl.Header>
<local:ComponentValueBox Unit="Ohm" HorizontalAlignment="Left"
Value="{x:Bind resistorValue, Mode=TwoWay}"
ValueChanged="changeR"/>
</controls:HeaderedContentControl>
And what I see (in the flyout) is:
Not quite like the GroupBox control..
What I would like to see is something like following:
What Should I do?
UWP is different from WPF. UWP is based on windows runtime, WPF is based on .NET Framework. They all use XAML to layout UI elments, but they have different XAML rendering engine. You could not think that MS dropped the old classic control. They're totally on the different platform. We call 'UWP' as Unversal Windows Platform. For now, you're not able to find such a 'GroupBox', but it's a new platform, you might be able to see such a control in the future. Anything is possible.
For your requirement, like #Muzib said, you entirely could make a custom control to meet your requirement. I used UserControl TextBlock Border ContentControl to make such a 'GroupBox' for your reference.
Please see my following code sample:
<UserControl
x:Class="AppGroupBox.GroupBox"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:AppGroupBox"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
d:DesignHeight="300"
d:DesignWidth="400">
<Grid>
<TextBlock x:Name="HeaderTitle" Text="Header" Margin="7 0 0 0" LayoutUpdated="HeaderTitle_LayoutUpdated"></TextBlock>
<Border BorderBrush="Black" x:Name="border" BorderThickness="0 2 0 0" Margin="100 10 3 3" CornerRadius="0 5 0 0"></Border>
<Border BorderBrush="Black" BorderThickness="2 0 2 2" Margin="3 10 3 3" CornerRadius="5">
<ContentControl x:Name="Content" Margin="10 10 10 10">
</ContentControl>
</Border>
</Grid>
public sealed partial class GroupBox : UserControl
{
public GroupBox()
{
this.InitializeComponent();
}
public string Header
{
get { return (string)GetValue(HeaderProperty); }
set { SetValue(HeaderProperty, value); }
}
// Using a DependencyProperty as the backing store for Header. This enables animation, styling, binding, etc...
public static readonly DependencyProperty HeaderProperty =
DependencyProperty.Register("Header", typeof(string), typeof(GroupBox), new PropertyMetadata("Your Header", HeaderPropertyChangedCallback));
public static void HeaderPropertyChangedCallback(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if (e.NewValue != e.OldValue)
{
(d as GroupBox).HeaderTitle.Text = e.NewValue?.ToString();
//(d as GroupBox).border.Margin = new Thickness((d as GroupBox).HeaderTitle.ActualWidth, 10, 3, 3);
}
}
public object CustomContent
{
get { return (object)GetValue(CustomContentProperty); }
set { SetValue(CustomContentProperty, value); }
}
// Using a DependencyProperty as the backing store for Content. This enables animation, styling, binding, etc...
public static readonly DependencyProperty CustomContentProperty =
DependencyProperty.Register("CustomContent", typeof(object), typeof(GroupBox), new PropertyMetadata(null,PropertyChangedCallback));
public static void PropertyChangedCallback(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if (e.NewValue != e.OldValue)
{
(d as GroupBox).Content.Content = e.NewValue;
}
}
private void HeaderTitle_LayoutUpdated(object sender, object e)
{
border.Margin = new Thickness(HeaderTitle.ActualWidth+10,10,3,3);
}
}
<local:GroupBox Header="My GroupBox" Height="300" Width="500">
<local:GroupBox.CustomContent>
<StackPanel>
<RadioButton Content="r1"></RadioButton>
<TextBox></TextBox>
</StackPanel>
</local:GroupBox.CustomContent>
</local:GroupBox>
I don't think there's such controls in UWP. Most probably you have to make your own CustomControl to achieve something that looks exactly lik that in UWP.
But hey, you can achieve something like that with a 'customized' ListView. Look at this:
<ListView Header="I am a header" BorderThickness="1" BorderBrush="Red" Width="250" Height="200" SelectionMode="None">
<ListView.HeaderTemplate>
<DataTemplate>
<ListViewHeaderItem Content="{Binding}"/>
</DataTemplate>
</ListView.HeaderTemplate>
<RadioButton>Any Value</RadioButton>
<RadioButton>1% standard?</RadioButton>
<RadioButton>5% standard</RadioButton>
</ListView>
It produces this output:
Of course You can make these items more dense if you want so.

uwp twoway binding not updating UI

I have the following XAML code, where I have a TextBox for user input (phone number) and GridView for user contacts.
<GridView x:Name="ContactsCollection" Grid.Row="1" Style="{StaticResource DefaultGridView}" IsItemClickEnabled="True" ItemsSource="{Binding UserContacts}" ItemTemplate="{StaticResource HorizontalGridViewDataTemplate}" ItemContainerStyle="{StaticResource DefaultGridViewItemContainer}">
<i:Interaction.Behaviors>
<c:EventTriggerBehavior EventName="SelectionChanged">
<c:InvokeCommandAction Command="{Binding SelectContactCommand}" CommandParameter="{Binding SelectedItem, ElementName=ContactsCollection}"/>
</c:EventTriggerBehavior>
</i:Interaction.Behaviors>
<GridView.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal"/>
</ItemsPanelTemplate>
</GridView.ItemsPanel>
And my TextBox that is binded to the Recipient in the ViewModel.
<TextBox x:Uid="Recipient" Text="{Binding Recipient, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" PreventKeyboardDisplayOnProgrammaticFocus="True" toolkitControls:TextBoxMask.Mask="7(999)999-99-99" toolkitControls:TextBoxMask.PlaceHolder="X" InputScope="NumericPin" HeaderTemplate="{StaticResource UiControlHeaderDataTemplate}" Style="{StaticResource DefaultTextBoxStyle}"/>
Here goes code from the ViewModel.
public string Recipient
{
get { return _recipient; }
set
{
if (value != _recipient)
{
_recipient = value;
RaisePropertyChanged(nameof(Recipient));
ContinueTransferCommand.RaiseCanExecuteChanged();
}
}
}
Now, when I click any contact from the GridView the following functions is called, that assign contact's phone number to the Recipient property.
private void SelectContactCommandAction(object contact)
{
Contact c = contact as Contact;
if (c.Phones?.Count > 0)
Recipient = FormatDataHelper.FormatPhoneNumber(c.Phones.FirstOrDefault().Number);
}
When I click any contact for the FIRST time, the Recipient property is updated, and the UI is updated too. But, if I select other contact, in the debug mode I can see, that Recipient property is updated and saved new value, but the UI (TextBox) is not updated at all. The only way it works, I have to delete any character from the TextBox and select a contact again, in that case UI value will be updated again.
Can somebody please explain this?

PrepareContainerForItemOverride works different in Desktop than in Mobile UWP

I wanted to change the color of an item of ListView according the data value.
It would be easy doing:
<ListView.ItemContainerStyle>
<Style TargetType = "ListViewItem" >
< Setter Property="Background" Value="{Binding EventType, Converter={StaticResource EventTypeToBackColorConverter}}" />
</ListView.ItemContainerStyle>
But the thing is that UWP does not support binding in Setter Properties.
My second attempt was overriding PrepareContainerForItemOverride of the ListView:
public class EventListView : ListView
{
protected override void PrepareContainerForItemOverride(DependencyObject element, object item)
{
base.PrepareContainerForItemOverride(element, item);
var listViewItem = element as ListViewItem;
var ev = item as EventType;
if(ev.Warning)
listViewItem.Background = new SolidColorBrush(Color.Red);
}
}
The above code works fine running in a PC with Windows 10 and UWP. It colors in red some items according the underlying data. When I run the same app in Windows Mobile, at beginning it works fine, but when I scroll up and then I scroll down, returning to the original view that was ok at beginning, now other items are also in red color.
What I am missing?
I am not sure the reason, but the following code works for me:
public class EventListView : ListView
{
protected override void PrepareContainerForItemOverride(DependencyObject element, object item)
{
base.PrepareContainerForItemOverride(element, item);
var listViewItem = element as ListViewItem;
var ev = item as EventType;
if(ev.Warning)
listViewItem.Background = new SolidColorBrush(Color.Red);
else
listViewItem.Background = null;
}
}
I have added listViewItem.Background = null
This is because when there are a large number of Items, by default ListView has implement the function of data virtualization. It's not a good idea to disable this function since it can achieve a better performance.
But for your scenario, there is a much easier method to solve your problem. Since you're trying to modify the style of ListViewItem in the code behind, and we can't modify the existed one, we can set a new style of ListViewItem to ListView for example like this:
private void Button_Click(object sender, RoutedEventArgs e)
{
var dynamicStyle = new Style();
dynamicStyle.TargetType = typeof(ListViewItem);
dynamicStyle.Setters.Add(new Setter(BackgroundProperty, Colors.Red));
listView.ItemContainerStyle = dynamicStyle;
}
Only one problem is, if you are setting the Background property to all the ListViewItem, it makes no difference than binding data to the Background property of ListView or setting the Background to ListView like this:
listView.Background = new SolidColorBrush(Colors.Red);
So I just assume that you want to modify the root control in the DataTemplate for example like the Grid in the following xaml:
<ListView x:Name="listView" ItemsSource="{x:Bind collection}">
<ListView.ItemContainerStyle>
<Style TargetType="ListViewItem" x:Name="myListItemStyle">
<Setter Property="HorizontalContentAlignment" Value="Stretch" />
</Style>
</ListView.ItemContainerStyle>
<ListView.ItemTemplate>
<DataTemplate>
<Grid HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
<TextBlock Text="{Binding Testtext}" />
</Grid>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
Then in this scenario, you can use data binding probably like this:
<DataTemplate>
<Grid HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Background="{Binding EventType, Converter={StaticResource EventTypeToBackColorConverter}}">
<TextBlock Text="{Binding Testtext}" />
</Grid>
</DataTemplate>
Any way, if you insist to change some property of all ListViewItem in the ListView, you can use the first method I provided.

Bind CommandParameter to SelectedItem of GridView

I work an a Windows 8 application which shows a GridView on one page. When ever the user selects an item of this grid and clicks on a button, the next page is loaded with detail information of the selected item.
I am using MVVM for this and have a DelegateCommand from Prims:
public DelegateCommand<Route> ShowRouteDetailsCommand { get; private set; }
This command is initialized inside the constructor:
this.ShowRouteDetailsCommand = new DelegateCommand<Route>(this.ShowRouteDetails);
The navigation is done by Prisms navigation service:
private void ShowRouteDetails(Route route)
{
this.NavigationService.Navigate(PageNames.RouteDetails, route.Id);
}
The routes are shown inside a GridView:
<GridView x:Name="RouteGrid"
ItemsSource="{Binding Routes}"
SelectionMode="Single">
<GridView.ItemTemplate>
<DataTemplate> ...
The command is currently added inside the app bar (just for testing):
<AppBarButton Command="{Binding ShowRouteDetailsCommand}"
CommandParameter="{Binding SelectedValue,
ElementName=RouteGrid, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
Icon="Forward" />
My problem is, that the parameter of ShowRouteDetails is allways empty. It doesn't even matter if I try GridViews SelectedValue or SelectedItem property.
I know that I could easily add a SelectedRoute property, bind the SelectedItem to it and use it in ShowRouteDetails but this seems dirty to me.
Why don't you just create a var in your viewModel and bind it to the SelectedItem of the gridView? In this way, when you run the command, you have only to read the value of that var.
<GridView x:Name="RouteGrid" ItemsSource="{Binding Routes}"
SelectionMode="Single" SelectedItem="{Binding myVar}">
<GridView.ItemTemplate>
<DataTemplate>

Why can't get validation error display in validationSummary?

I have a form with some validations set in entity metadata class. and then binding entity instance to UI by VM. Something as below:
Xaml like:
<Grid x:Name="LayoutRoot">
<StackPanel VerticalAlignment="Top">
<input:ValidationSummary />
</StackPanel>
<TextBox Text="{Binding Name, Mode=TwoWay}" />
<ComboBox x:Name="xTest" ItemsSource="{Binding MyList}"
SelectedItem="{Binding MyItem,Mode=TwoWay,
DisplayMemberPath="MyName"
ValidatesOnDataErrors=True,
ValidatesOnNotifyDataErrors=True,
ValidatesOnExceptions=True,
NotifyOnValidationError=True,UpdateSourceTrigger=Explicit}" />
</Grid>
Code-behind like:
public MyForm()
{
InitializeComponent();
this.xTest.BindingValidationError +=new EventHandler<ValidationErrorEventArgs>((s,e)=>{
BindingExpression be = this.xTest.GetBindingExpression(ComboBox.SelectedItemProperty);
be.UpdateSource();
if (e.Action == ValidationErrorEventAction.Added)
((ComboBox)s).Foreground = new SolidColorBrush(Colors.Red);
});
}
Metadata like:
[Required]
public string Name { get; set; }
[RequiredAttribute]
public int MyItemID { get; set; }
But when running the app, I got nothing display in valudationSummary.
For CombBox, even there is error, looks like BindingValidationError event is never fired.
How to resolve it?
Why are you using an Explicit UpdateSourceTrigger?
Silverlight validation happens inside the binding framework, when the binding is updating the source object. The way you have this, there won't be a binding validation error because you never tell the binding to update the source object. Well, actually you do, but it happens inside the validation error event handler. You've written chicken-and-egg code.
Remove your UpdateSourceTrigger on your binding or set it to Default.
Remove the explicit call to BindingExpression.UpdateSource.
Remove setting the ComboBox foreground to red - you are using NotifyOnValidationError=True, which eliminates any need to manually color the control.
Remove the DisplayMemberPath from the binding
So your XAML:
<Grid x:Name="LayoutRoot">
<StackPanel VerticalAlignment="Top">
<input:ValidationSummary />
<ComboBox x:Name="xTest" ItemsSource="{Binding MyList}"
SelectedItem="{Binding MyItem,
Mode=TwoWay,
ValidatesOnDataErrors=True,
ValidatesOnNotifyDataErrors=True,
ValidatesOnExceptions=True,
NotifyOnValidationError=True}" />
</StackPanel>
</Grid>
And your code:
public MyForm()
{
InitializeComponent();
// you don't need anything here to have the validations work
}