<ListView Name="myList" Background="Transparent" Margin="15,88,15,15">
<ListView.ItemTemplate>
<DataTemplate>
<StackPanel>
<Grid Height="100">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="200"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<StackPanel Grid.Column="0" Margin="5">
<TextBlock Name="xName" Text="{Binding Name}" FontSize="30" Margin="10,0,5,0" FontWeight="Medium"/>
<TextBlock Name="xNo" Text="{Binding No}" FontSize="25" Margin="10,0,5,0" TextTrimming="CharacterEllipsis"/>
</StackPanel>
<Grid Grid.Column="1" Margin="5">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="1*"/>
<ColumnDefinition Width="1*"/>
</Grid.ColumnDefinitions>
<RadioButton Grid.Column="0" Name="r1" Content="1" Width="10" Margin="5,15,-2,5"/>
<RadioButton Grid.Column="1" Name="r2" Content="2" Width="10" Margin="5,15,-2,5"/>
</Grid>
</Grid>
</StackPanel>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
Now I want to retrieve each item in ListView i.e, the controls in it. The TextBlocks content and to know which RadioButton is selected.
I tried taking classes like this
public class Att
{
public string Name;
public string No;
public RadioButton r1;
public RadioButton r2;
}
There are separate sources for the content of the TextBoxes in the ListView. They come from different classes. I tried retrieving the items using above class Att.
But it is showing some type conversion errors. Please anyone help me! I'm a beginner.
Thanks is advance.
Thanks for all the support!
Well I tried doing this on my own and finally I got it. What I really wanted is to know which RadioButton is checked. I tried taking class Att for retrieving the items in ListView. I made modifications to the Att Class and added properties r1 and r2 of type bool instead of RadioButton and binded this property to the IsChecked property of the RadioButton in XAML and also mode of binding is TwoWay. So the changes done in the XAML can be reflected in the source list of items.
Related
I have this code as my list view:
<ListView x:Name="listViewPhotoLibrary">
<ListView.ItemTemplate>
<DataTemplate>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="47"/>
<ColumnDefinition Width="100"/>
</Grid.ColumnDefinitions>
<Button Content="X"/>
<TextBlock Foreground="Teal"/>
</Grid>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
and i use a list of string as its item source
List<string> libraries = new List<string>(Properties.Settings.Default.Paths.Split(new char[] { ';' }));
libraries = libraries.Where(s => !string.IsNullOrEmpty(s)).Distinct().ToList();
listViewPhotoLibrary.ItemsSource = libraries;
My problem is that the list view is not showing the text.
this is what i get.
what am I doing wrong and what are some good reads for understanding data templates?
The element in the grid are missing a column number, also the text box has no content, try this:
<Button Grid.Column="0" Content="X"/>
<TextBlock Grid.Column="1" Foreground="Teal" Text="Some text"/>
To display the actual content of the items in the list, you need to use the Binding object, in your case, since the object are just string the binding declaration is simple:
<TextBlock Grid.Column="1" Foreground="Teal" Text="{Binding}"/>
Which is equivalent to:
<TextBlock Grid.Column="1" Foreground="Teal" Text="{Binding Path=."/>
The documentation is a good start, read well noted WPF questions on SO is also a good idea.
Referencing this example:
https://learn.microsoft.com/en-us/dotnet/framework/wpf/data/how-to-bind-to-a-collection-and-display-information-based-on-selection
(some relevant code snippets:)
<Window.Resources>
<local:People x:Key="MyFriends"></local:People>
<DataTemplate x:Key="DetailTemplate">
<Border Width="300" Height="100" Margin="20"
BorderBrush="Aqua" BorderThickness="1" Padding="8">
<Grid>
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<TextBlock Grid.Row="0" Grid.Column="0" Text="First Name:"/>
<TextBlock Grid.Row="0" Grid.Column="1" Text="{Binding Path=FirstName}"/>
<TextBlock Grid.Row="1" Grid.Column="0" Text="Last Name:"/>
<TextBlock Grid.Row="1" Grid.Column="1" Text="{Binding Path=LastName}"/>
<TextBlock Grid.Row="2" Grid.Column="0" Text="Home Town:"/>
<TextBlock Grid.Row="2" Grid.Column="1" Text="{Binding Path=HomeTown}"/>
</Grid>
</Border>
</DataTemplate>
</Window.Resources>
<ListBox Width="200" IsSynchronizedWithCurrentItem="True"
ItemsSource="{Binding Source={StaticResource MyFriends}}"/>
<ContentControl x:Name="contentControl1"
Content="{Binding Source={StaticResource MyFriends}}"
ContentTemplate="{StaticResource DetailTemplate}" />
Both ListBox.ItemsSource and ContentControl.Content bind to the same source (MyFriends, an instance of the People class which derives from ObservableCollection<Person>). If my understanding is correct, this means that both the ListBox.ItemsSource and ContentControl.Content properties will be bound to the same implicitly created instance of ListCollectionView.
I understand that setting ListBox.IsSynchronizedWithCurrentItem="True" synchronizes ListBox.SelectedItem and ItemCollection.CurrentItem.
DetailTemplate (above) displays the details of the selected ListBox item, despite being 'bound' to a ListCollectionView. Specifying Path=/ (what I thought would be necessary to achieve the resulting behavior) does not have any effect - it's as if WPF knows to do it implicitly somehow:
<ContentControl x:Name="contentControl1"
Content="{Binding Source={StaticResource MyFriends}, Path=/}"
ContentTemplate="{StaticResource DetailTemplate}" />
As a test, I created another ContentControl with Content bound to a DataTemplate containing a ListBox:
<ContentControl x:Name="contentControl2"
Content="{Binding Source={StaticResource MyFriends}}"
ContentTemplate="{StaticResource DetailTemplate2}" />
<DataTemplate x:Key="DetailTemplate2">
<ListBox ItemsSource="{Binding}"></>
</DataTemplate>
And it displayed the list.
My question is: Why does DataTemplate get the selected Person object while the ListBox and DetailTemplate2 get the People collection?
(the behavior is desirable, I just don't understand what black magic is occurring under the hood to make it so)
Is a good question! I didn't notice that until read your post. So, after did some digging from source code of PropertyPathWorker, it appears that when PropertyPathWorker failed to solve a member of an object, in your case, it try to solve 'FirstName', 'LastName' ect. with 'MyFriends', it will try to solve it with the view of the object. And if still failed, it will try to solve it with view's CurrentItem, and that's where the magic happened. You can find those codes in PropertyPathWorker.UpdateSourceValueState(int k, ICollectionView collectionView, object newValue, bool isASubPropertyChange) and PropertyPathWorker.ReplaceItem(int k, object newO, object parent).
I am trying to get a custom UserControl to render in a ListBox, but nothing is being rendered. I came across this question and solution which works for the simple example, but my situation is a little different. I have a PersonControl for a Person object and a CoupleControl that can reference two PersonControl controls.
I've tried a couple things in the CoupleControl which haven't worked. I commented out one of the ways:
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="1*" />
<ColumnDefinition Width="1*" />
</Grid.ColumnDefinitions>
<Control:PersonControl Grid.Column="0"
x:Name="LeftPerson" />
<Control:PersonControl Grid.Column="1"
x:Name="RightPerson" />
<!-- This is how I'd like to do it in case I create other controls
I wish to replace the PersonControls (e.g. AnimalControl) -->
<!--<UserControl Grid.Column="0"
x:Name="LeftPerson" />-->
<!--<UserControl Grid.Column="1"
x:Name="RightPerson" />-->
</Grid>
The relevant WPF snippet for the list box:
<ListBox Grid.Row="1"
ItemsSource="{Binding Persons}">
<ListBox.ItemTemplate>
<DataTemplate>
<Control:CoupleControl />
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
In the code-behind:
public ObservableCollection<CoupleControl> Persons { get; private set; }
Person joe = new Person("Joe", "Smith", Person.SexType.Male);
Person jane = new Person("Jane", "Smith", Person.SexType.Female);
PersonControl joeControl = new PersonControl();
PersonControl janeControl = new PersonControl();
joeControl.DataContext = joe;
janeControl.DataContext = jane;
CoupleControl coupleControl = new CoupleControl();
coupleControl.LeftPerson.DataContext = joe;
coupleControl.RightPerson.DataContext = jane;
//coupleControl.LeftPerson.Content = joeControl; // Also doesn't work
//coupleControl.RightPerson.Content = janeControl; // Also doesn't work
Persons.Add(coupleControl);
Can someone help me get the CoupleControl to render in a ListBox?
Your approach is a bit too code-heavy for my taste, why not set DataContext in XAML?
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition />
<ColumnDefinition />
</Grid.ColumnDefinitions>
<Control:PersonControl DataContext="{Binding LeftPerson}" />
<Control:PersonControl DataContext="{Binding RightPerson}" Grid.Column="1" />
</Grid>
Or maybe even drop UserControls altogether if they are not so complex? In this case using DataTemplates can be faster and simpler. Say we defined templates for Person and Couple in Window resources (Couple is just a class with LeftPerson and RightPerson properties):
<Window.Resources>
<DataTemplate x:Key="personTemplate" DataType="TestWPF:Person">
<Border BorderThickness="1" BorderBrush="Green" CornerRadius="5">
<StackPanel>
<TextBlock Text="{Binding FirstName}" />
<TextBlock Text="{Binding LastName}" Margin="3,0,0,0" />
</StackPanel>
</Border>
</DataTemplate>
<DataTemplate x:Key="coupleTemplate" DataType="TestWPF:Couple">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition />
<ColumnDefinition />
</Grid.ColumnDefinitions>
<ContentControl Content="{Binding LeftPerson}"
ContentTemplate="{StaticResource personTemplate}" />
<ContentControl Content="{Binding RightPerson}"
ContentTemplate="{StaticResource personTemplate}" Grid.Column="1" />
</Grid>
</DataTemplate>
</Window.Resources>
Then you set ItemTemplate for your ListBox:
<ListBox Grid.Row="1" ItemsSource="{Binding Persons}" ItemTemplate="{StaticResource coupleTemplate}" />
This way you can make some more templates for the types you need and just set them in ListBox in one single line.
I have a listbox and I need a way to pass the selected item to a UserControl.
How can I do it?
<Grid >
<ListBox Name="lbPersonaggi" HorizontalContentAlignment="Stretch" SelectionMode="Single"><!--SelectionChanged="lbPersonaggi_SelectionChanged"-->
<ListBox.ItemTemplate>
<DataTemplate>
<Grid Margin="0,2">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="100" />
</Grid.ColumnDefinitions>
<TextBlock Name="TBPG" Text="{Binding Personaggio}" MouseUp="ClickPG" />
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
If you just want to set the selected item as DataContext for another UserControl you write something like this
<UserControl DataContext="{Binding lbPersonaggi.SelectedItem}" />
You don't need a property in your viewmodel to store the selected item.
Try this in your ListBox Definition header:
SelectedItem="{Binding Path=YourPropertyWhereYouWantToStoreTheValue, Mode=OneWayToSource}"
And then Re-use this property in your second Control.
I think it will work.
lets begin with the scenario:
I have an ItemsControl inside a UserControl. In this ItemsControl I have a dynamicly created DataTemplate which is created and added in codebehind. As there doesn't seem to be a nice way to create a DataTemplate in codebehind I had to programmatically generate the xaml code for my DataTemplate into a string and then create a DataTemplate object out of it through XamlReader:
StringBuilder stringBuilder = new StringBuilder();
XmlWriter xmlWriter = XmlWriter.Create(stringBuilder);
... // use xmlWrite to generate desired xaml
// substring is use to cut out the xml declaration
DataTemplate template = (DataTemplate)XamlReader.Load(stringBuilder.ToString().Substring(39));
myItemsControl.ItemTemplate = template;
The generated XAML code looks like this and is actually used (the items get rendered as expected):
<DataTemplate xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
<Grid HorizontalAlignment="Stretch" Margin="0,0,0,0">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="100" />
<ColumnDefinition Width="100" />
<ColumnDefinition Width="100" />
</Grid.ColumnDefinitions>
<TextBlock Text="{Binding b0}" Grid.Column="0" />
<TextBox Text="{Binding b1, Converter={StaticResource customConverter}}" HorizontalAlignment="Stretch" Grid.Column="1" LostFocus="TxtAttribute_LostFocus" />
<TextBox Text="{Binding b2, Converter={StaticResource customConverter}}" HorizontalAlignment="Stretch" Grid.Column="2" LostFocus="TxtAttribute_LostFocus" />
<TextBox Text="{Binding b3, Converter={StaticResource customConverter}}" HorizontalAlignment="Stretch" Grid.Column="3" LostFocus="TxtAttribute_LostFocus" IsReadOnly="True" />
</Grid>
In case you wonder: the xmlns attribute is needed by the XamlReader to render the control, else you'll get an exception when reaching the code.
My problem:
now while the items look like expected and data is correctly bound neither my customConverter that should reformat the bound data, nor the LostFocus event are correctly applied. I don't get any error messages or warnings, converter and event just don't get called. Anyone an idea why and how I can get this to work?
Update:
I reached a point where I have to solve this problem or to try a different approach.
In my last tests I tried to add the Converter directly in the DataTemplate but I had no luck. The generated code now looks like this:
<DataTemplate xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:Conv="clr-namespace:my.Namespace" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
<Grid HorizontalAlignment="Stretch" Margin="0,0,0,0">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="80" />
<ColumnDefinition Width="80" />
<ColumnDefinition Width="80" />
</Grid.ColumnDefinitions>
<Grid.Resources>
<Conv:DecimalConverter x:Name="cnvDecimalConverter" />
</Grid.Resources>
<TextBlock Text="{Binding b0}" Grid.Column="0" />
<TextBox Text="{Binding b1, Converter={StaticResource cnvItemsDecimalConverter}}" HorizontalAlignment="Stretch" Grid.Column="1" LostFocus="TxtAttribute_LostFocus" />
<TextBox Text="{Binding b2, Converter={StaticResource cnvItemsDecimalConverter}}" HorizontalAlignment="Stretch" Grid.Column="2" LostFocus="TxtAttribute_LostFocus" />
<TextBox Text="{Binding b3, Converter={StaticResource cnvItemsDecimalConverter}}" HorizontalAlignment="Stretch" Grid.Column="3" LostFocus="TxtAttribute_LostFocus" IsReadOnly="True" />
</Grid>
</DataTemplate>
Any ideas?
Update 2:
As I just found out XamlReader.Load() just is not able to hook up events. See this Thread in the Silverlight Forums
The Converters should work, I guess I still have some kind of namespace problem I don't see. I'm kind of out of options with my "simple" ItemsControl approach so I think it's time to look for another method to reach my needs.
Just to clear up the situation: It is not possible to generate dynamic DataTemplates with events through generating an xaml string and extract the control from this. The only option to parse xaml code with events is through Application.LoadComponent which needs a URI to work.
I ended up using nested ItemControls to create my "dynamic" behaviour.