Getting Listbox Value WP7 - c#

how to get value from the textblock , which is present in listbox ....
here is the code xaml :
<ListBox Height="707" HorizontalAlignment="Left" Margin="12,0,0,0" Name="listBox1" VerticalAlignment="Top" Width="456" Background="White" Foreground="#FF09090C" ItemsSource="{Binding}" SelectionChanged="listBox1_SelectionChanged">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Name="textBlock3" FontSize="18" Foreground="Blue" Margin="2" Text="{Binding Title.Text}" TextWrapping="Wrap" />
<TextBlock FontSize="16" Foreground="Gray" Margin="2" Text="{Binding Summary.Text}" TextWrapping="Wrap" />
<TextBlock FontSize="1" Foreground="Gray" Margin="2" Text="{Binding Id}" TextWrapping="Wrap" Visibility="Collapsed" />
<Button Name="h1" Content="Press" Height="10" Width="40"></Button>
<TextBlock Foreground="Gray" Margin="2" Text="________________________________________________________________________________________" FontSize="8"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>

You don't get the value directly from the TextBlock.
Instead what you do is bind the SelectedItem to a property on your viewmodel. To get the value of the TextBlock directly would violate the priciples of MVVM (if you are using that pattern). The viewmodel presents the data, it has no clue how that data is being rendered to the UI. IOW it has no idea there are three TextBlocks.
<ListBox Height="707" SelectedItem={Binding MyViewModelProperty} >
... etc ...
This means that every time the selected item is changed, the new value will be populated into the bound property on the viewmodel. All you have to do then is access that object - it's as easy as that. This means you may also possibly be able to get rid of your SelectionChanged event hookup, depending on what it is doing.
However if you insist on getting the instance of the template used to present any particular data item in a list control, then this is the way to do it programmatically:
myListBox.ItemContainerGenerator.ContainerFromItem(myDataItem);
This will return you the StackPanel and its contents, you can then either use FindName() or just enumerate the child controls to find the one you are interested in.
FrameworkElement element = myListBox.ItemContainerGenerator.ContainerFromItem(myDataItem) as FrameworkElement;
if (element != null)
FrameworkElement child = element.FindName("myChildName");

Related

WPF Binding TextBlock value to display SelectedItem in ComboBox

I have a ComboBox and a couple of TextBlock fields.
I want to display the properties of a SelectedItem from the ComboBox on those Textblock's. Image
So that when I choose one of multiple user's the properties in the TextBlock will update to those of the SelectedItem. I have found an example, although it is using silverlight, and does not work entirely.
<ComboBox Grid.Row="0"
Grid.Column="0"
VerticalAlignment="Bottom"
VerticalContentAlignment="Center"
HorizontalContentAlignment="Left"
Margin="0"
Height="40"
Name="ComboBox"
ItemsSource="{Binding UserModels}"
SelectedItem="{Binding EnteredUserModel, Mode=TwoWay}">
<ComboBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding FirstName}"
Style="{StaticResource ResourceKey=ComboBoxItemTextBlock}"/>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
</Grid>
<TextBlock Grid.Row="1"
Grid.Column="0"
Margin="0 10 0 10" >
<Run Text="{DynamicResource firstName}" />
<Run Text=": " />
<Run Text="{Binding ElementName=ComboBox, Path=SelectedItem, UpdateSourceTrigger=PropertyChanged}" />
</TextBlock>
This is what I've tried. I added Name to the ComboBox so that I can access it's SelectedItem in my TextBlock. I need to get the SelectedItem.firstname, etc. At this stage i can only access the entire objects.
Am I missing some useful binding?
In order to show the FirstName property of the SelectedItem, just use an appropriate property path, i.e. SelectedItem.FirstName:
<Run Text="{Binding ElementName=ComboBox, Path=SelectedItem.FirstName}" />
or, since SelectedItem is bound to an EnteredUserModel property in your view model:
<Run Text="{Binding Path=EnteredUserModel.FirstName}" />
Setting UpdateSourceTrigger=PropertyChanged is not necessary. It has no effect in a OneWay Binding.
You're getting the EnteredUserModel-Object, because that's the selected item of the ComboBox. If you want the displayed text you must bind to the FirstName-Property.
Alternatively you can bind to EnteredUserModel.FirstName in your TextBox

UWP - can't access values in ItemsPanel

I have the following XAML but I can't seem to access the contents of the ItemsWrapGrid in the corresponding .CS file - can anyone tell me what I should be doing (here's the code behind and xaml) :
private void wifiTapped(object sender, TappedRoutedEventArgs e)
{
Debug.WriteLine("in here " + e.GetType().ToString());
ItemsWrapGrid wg = (ItemsWrapGrid) sender;
Debug.WriteLine(e.OriginalSource.ToString());
foreach (Control c in wg.Children)
{
Debug.WriteLine("Control " + c.Name);
}
Debug.WriteLine("leaving ");
}
<GridView VerticalAlignment="Top" ItemsSource="{Binding nets}" x:Name="GDView" ItemClick="gdViewClick" >
<GridView.ItemTemplate>
<DataTemplate x:Name="configDataTemplate" x:DataType="data:wifiNets" >
<StackPanel Height="300" Width="350" Margin="10" Name="dtStackPanel" >
<Image Source="Assets\wifiIcon.png" Width="200" Height="201" />
<StackPanel Orientation="Horizontal">
<TextBlock Text="Name" Margin="0,0,10,0"/>
<TextBlock Name="configSSID" Width="auto" Text="{x:Bind NetSSID}" FontSize="24" />
</StackPanel>
<StackPanel Orientation="Horizontal">
<TextBlock Text="Strength" Margin="0,0,10,0"/>
<!--<TextBlock Name="configStrength" Width="auto" Text="{x:Bind NetSSIDStrength}" FontSize="20" />-->
<ProgressBar Name="configProgBar" Maximum="5" Value="{x:Bind NetSSIDStrength}" Foreground="Green" />
</StackPanel>
<StackPanel Orientation="Horizontal">
<TextBlock Text="Connected" Margin="0,0,10,0"/>
<TextBlock Name="configConnectedTo" Text="{x:Bind NetSSIDConnected}" FontSize="20"/>
</StackPanel>
</StackPanel>
</DataTemplate>
</GridView.ItemTemplate>
<GridView.ItemsPanel>
<ItemsPanelTemplate>
<ItemsWrapGrid MaximumRowsOrColumns="10" Orientation="Vertical" Tapped="wifiTapped" />
</ItemsPanelTemplate>
</GridView.ItemsPanel>
</GridView>
Just to be clear, when I run this I have three items of data (so it's working) - but what I'd like to be able to do is click on any one of the three data items and be able to identify the individual controls and their values within the data panel.
Thanks in advance, this is driving me nuts.
Paul.
Set IsItemClickEnabled to true on your GridView, and hook into the ItemClick event on the GridView itself. From the event args, you can get the sender (most likely the GridViewItem UI element itself, of which your DataTemplate content is a child), and the ClickedItem, which is the bound datacontext of the datatemplate - in your case the instance of the data:wifiNets - which if your bindings work mean you won't actually have to look in the VisualTree at all.
If for some reason you want to recurse through the VisualChildren for the items of any ItemsControl, use the ContainerFromIndex or ContainerFromItem methods on the ItemsControl to get the ItemContainer hosting each instance of the datatemplate - although I wouldn't recommend doing this unless you really need too. Ideally you shouldn't often have a need for manually trawling the visual tree.

Adding a List of Songs to a ListBox

i am trying to make my own mediaplayer for Windows Phone 7 and for the first step, i want to display a List of all songs in my media library to select them.
As i understood the ListBox, i just have to name the texblocks like the attributes of my class, which would be "Song"
<ListBox FontSize="30" Name="songListGUI" Height="330" Margin="0,120,0,0">
<Button Width="430" Height="60" BorderThickness="0" Margin="0" >
<Button.Content>
<StackPanel Orientation="Horizontal" Width="420" Height="auto">
<TextBlock Name="Name" Text="{Binding Name}" FontSize="22"></TextBlock>
<TextBlock Text=" - " FontSize="22"></TextBlock>
<TextBlock Name="Artist" Text="{Binding Artist}" FontSize="22"></TextBlock>
</StackPanel>
</Button.Content>
</Button>
</ListBox>
And now i think, i should handle my list of songs to the GUI and i try to do that with:
songListGUI.ItemsSource = songs;
But then i get a "InvalidOperationException" - Items collection must be empty before using ItemsSource.
I found several problems like this, and they all created a new class, to display this content. But i would like to stick with the song class, as it comes in quite handy :/
Do you know what i am doing wrong here?
edit:
i just found the solution. Don´t know exactly why, but this change in the .xaml made my da :):
<ListBox FontSize="30" Name="songListGUI" Height="330" Margin="0,120,0,0">
<ListBox.ItemTemplate>
<DataTemplate>
<Button Width="430" Height="60" BorderThickness="0" Margin="0" >
<Button.Content>
<StackPanel Orientation="Horizontal" Width="420" Height="auto">
<TextBlock Name="Name" Text="{Binding Name}" FontSize="22"></TextBlock>
<TextBlock Text=" - " FontSize="22"></TextBlock>
<TextBlock Name="Artist" Text="{Binding Artist}" FontSize="22"></TextBlock>
</StackPanel>
</Button.Content>
</Button>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
Anybody could explan this to me?
ListBox is an ItemsControl. The content of an ItemsControl maps to the Items property. So by doing this:
<ListBox>
<SomeContent/>
</ListBox>
you're setting the Items property to <SomeContent/>. Since you aren't allowed to set the Items property and the ItemsSource property you get an exception.
When you do this:
<ListBox>
<ListBox.ItemTemplate>...</ListBox.ItemTemplate>
</ListBox>
You're not setting the content you're setting an attribute of the ListBox so there's no conflict.

Easiest way to access Texblock inside listbox itemtemplate

I have seen a lot of questions and answers with almost the same problem, but none of these answers arent working for me. Soo, my code is:
<ListBox ItemsSource="{Binding Avakuvaandmed}" x:Name="lboxandmed" HorizontalAlignment="Left" Height="552" VerticalAlignment="Top" Width="970" SelectionChanged="lboxandmed_SelectionChanged" >
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" x:Name="spanVärviSeda">
I HAVE TO GET VALUE OF THIS --> <TextBlock x:Name="IDbox" Width="50" Text="{Binding Id}"></TextBlock>
<TextBlock Width="130" Text="{Binding Nrmärk}"></TextBlock>
<TextBlock x:Name="txtKehtivus" Width="130" Text="{Binding Lõpp}"></TextBlock>
<TextBlock Width="130" Text="{Binding Eesnimi}"></TextBlock>
<TextBlock Width="130" Text="{Binding Perenimi}"></TextBlock>
<TextBlock Width="130" Text="{Binding Mark}"></TextBlock>
<TextBlock Width="130" Text="{Binding Mudel}"></TextBlock>
<TextBlock Width="130" Text="{Binding Aasta}"></TextBlock>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
And I have to get the value of the textblock named "IDbox".
Please can someone help me, or atleast give me a clue how.
Your code looks correct. If you want to access the Value of IDbox in code behind then you can do it by Avakuvaandmed.ElementAt(rowno).Id because you are binding Id to the IDBox. If you want to access the BoxId value in xaml. Then use binding as follows:
{Binding Avakuvaandmed[rowno],Path=Id}
You can also access Textblock value by using VisualTreeHelper class. You will need to go traverse all elements in ListBox.

Binding data to ListView doesn't work (Metro UI)

When I put this code into my XAML file:
<TextBlock Text="{Binding Name}" FontSize="16" Margin="15,0,0,0" />
It shows me Name value but when I try show it via ListView:
<ListView x:Name="ItemListView"
ItemsSource="{Binding Items}"
Margin="60,0,0,10">
<ListView.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Text="{Binding Name}"
FontSize="24" Margin="5,0,0,0" TextWrapping="Wrap" />
<TextBlock Text="{Binding Artist}"
FontSize="16" Margin="15,0,0,0"/>
</StackPanel>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
It doesn't show up :( What could be wrong?
If the page inherits from LayoutAwarePage, like it will by default when created from a template, the DataContext will be set to a property named DefaultViewModel. Properties exposed in your codebehind will not be bound to.
You are looking at two different objects in the sample. In the textbox you are looking at the Name of the object in the datacontext, in the listview you are looking at the Items[x].Name for each item you bind to. If you need to reference the Name from the datacontext rather than the Items collection you will need to bind the source to an Element not inherit it.

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