Im trying to add items to the combo box from the code behind to the item template but im getting null. This is what I have so far:
XAML:
<ListBox x:Name="lsbCiertoYFalsoInsideTemplate" Margin="40,0,0,0" ItemTemplate="{StaticResource CiertoYFalsoExcerciseDataTemplate}"/>
App.xaml:
<DataTemplate x:Key="CiertoYFalsoExcerciseDataTemplate">
<Grid>
<StackPanel x:Name="stckCiertoYFalsoInsideTemplate" Margin="0" Orientation="Vertical" Width="1100">
<StackPanel x:Name="stckPreguntasCiertoYFalso" Orientation="Horizontal">
<Grid Height="50" Width="65" DataContext="{Binding CustomValueList}" VerticalAlignment="Top">
<ComboBox x:Name="cbExercises" Style="{StaticResource SA_ComboBoxStyle}" ItemsSource="{Binding CustomOption}" BorderBrush="#CC8C8C8C" VerticalAlignment="Top">
</ComboBox>
</Grid>
<TextBlock HorizontalAlignment="Center" Margin="5,3,0,0" TextWrapping="Wrap" Text="{Binding QuestionNumber}" VerticalAlignment="Top" FontWeight="Bold" Foreground="Black" Width="26" FontFamily="{Binding FontFamily, Source={StaticResource TextBlockStyleManager}}" FontSize="{Binding FontSize, Source={StaticResource TextBlockStyleManager}}"/>
<TextBlock TextWrapping="Wrap" Text="{Binding Question}" Foreground="Black" VerticalAlignment="Top" FontSize="{Binding FontSize, Source={StaticResource TextBlockStyleManager}}" Margin="10,3,0,0" Width="968" FontFamily="{Binding FontFamily, Source={StaticResource TextBlockStyleManager}}"/>
</StackPanel>
</StackPanel>
</Grid>
</DataTemplate>
The error im getting is object out of range.
Code:
private void ComboBoxExercises()
{
ComboBox comboBox = new ComboBox();
ComboboxItem item = new ComboboxItem();
item.Text = "A";
comboBox = (ComboBox)lsbCiertoYFalsoInsideTemplate.FindName("cbExercises");
comboBox.SelectedIndex = 0;
comboBox.Items.Add(item);
}
public class ComboboxItem
{
public string Text { get; set; }
public override string ToString()
{
return Text;
}
}
There's a disconnect in what you're trying to do here. You've specified an ItemTemplate - which defines how each item in the list will look.
But then you're trying to get one single ComboBox back out via the FindName function. Which leads me to believe that you're really intending to set the Template, not the ItemTemplate.
That said, I think the error you're getting is because you're setting the SelectedIndex to 0 when the ComboBox has no items in it. You're telling it to select the first one, but there's nothing to select. You should add the item first, then select it.
Related
I have a listbox containing a choice of text answers taken from the database and containing html languages, such as: <p>, etc. I want to display it so that the html language is not displayed. I tried to display it in the webview, but <p>, etc. is still visible.
XAML:
<ListBox Name="ListOption" Grid.Row="1" Margin="10,20,10,0" Height="auto" xmlns:m="using:KipinSchool_Win10.TryoutData.Models" SelectionChanged="ListAlternatives_SelectionChanged" VerticalAlignment="Stretch" HorizontalAlignment="Stretch">
<ListBox.ItemTemplate>
<DataTemplate x:DataType="m:DBOption">
<StackPanel Orientation="Horizontal">
<WebView Margin="10,10,10,10" local:MyProperties.HtmlString="{Binding Option}" MinHeight="40" MaxHeight="300" HorizontalAlignment="Stretch" Tag="{Binding OID}"/>
<TextBlock Text="{Binding Option}" Tag="{Binding OID}" FontSize="19"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
Code:
string strA = #"SELECT DISTINCT* FROM DBOption WHERE QID='" + question[0] + "'";
var alternative = objConn.Prepare(strA);
ObservableCollection<DBOption> Items = new ObservableCollection<DBOption>();
int i = 0;
while (alternative.Step() == SQLiteResult.ROW)
{
Items.Add(new DBOption(alternative[0].ToString(), alternative[1].ToString(), alternative[2].ToString(), alternative[3].ToString()));
}
Binding myBinding = new Binding();
myBinding.Source = Items;
ListOption.SetBinding(ItemsControl.ItemsSourceProperty, myBinding);
How to handle it?
I tried to display it in the webview, but etc. is still visible. XAML:
I could reproduce your issue, the problem is that you have not set width and height property for WebView. And html string does not contain the content height. So the WebView will not display correctly. Please modify the code like the following.
<ListBox.ItemTemplate>
<DataTemplate >
<StackPanel Orientation="Horizontal">
<WebView Margin="10,10,10,10"
local:MyProperties.HtmlString="{Binding Option}"
Height="400" Width="200"
HorizontalAlignment="Stretch"
Tag="{Binding OID}"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
In UWP C#, I have one ListView in upper row & another in lower row. When I drag a listitem from upper ListView & drop it on lower ListView, I am getting the source. But, I am unable to get the destination. ie) the listview item/(Folder object in my case) where I dropped.
<ListView Name="ListviewCars"
CanDragItems="True" DragItemsStarting="ListviewCars_DragItemsStarting"
SelectionMode="Single" IsItemClickEnabled="True"
DataContext="Cars" ItemsSource="{Binding CarsCollection}">
<ListView.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Background="Transparent" Height="80" Orientation="Horizontal"
HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
</ItemsPanelTemplate>
</ListView.ItemsPanel>
<ListView.ItemTemplate >
<DataTemplate>
<Grid Name="GrdCars" >
<Grid Height="80" Width="90" Padding="5">
<Grid.Background>
<ImageBrush Stretch="Uniform" ImageSource="Assets/car.png"/>
</Grid.Background>
<TextBlock Text="{Binding Name}" FontWeight="Bold" TextWrapping="Wrap" TextAlignment="Center"
HorizontalAlignment="Center" VerticalAlignment="Center" />
</Grid>
</Grid>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
<ListView Name="GrdViewImg" ScrollViewer.VerticalScrollBarVisibility="Disabled"
AllowDrop="True" DragOver="Image_DragOver"
Drop="Image_OnDrop"
DataContext="Folders" ItemsSource="{Binding FolderCollection}">
<ListView.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Background="Transparent" Height="80" Orientation="Horizontal" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
</ItemsPanelTemplate>
</ListView.ItemsPanel>
<ListView.ItemTemplate >
<DataTemplate>
<Grid Name="GrdForFolderMenu" RightTapped="GrdForFolderMenu_RightTapped">
<Grid Height="80" Width="90" Padding="5">
<Grid.Background>
<ImageBrush Stretch="UniformToFill" ImageSource="Assets/Folderimage.png"/>
</Grid.Background>
<TextBlock Text="{Binding Name}" FontWeight="Bold" TextWrapping="Wrap" TextAlignment="Center" HorizontalAlignment="Center" VerticalAlignment="Center" />
</Grid>
</Grid>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
I have found a simple solution myself. I get the source from DragItemsStarting event of the SoureListView. and target item (as mentioned by ashchuk) from a Grid placed inside Datatemplate of Target ListView. as shown below. Everything works fine now!
(Cars is my Source custom list item. Folders is my Target custom list item)
private void SoureListView_DragItemsStarting(object sender, DragItemsStartingEventArgs e)
{
Cars x = e.Items[0] as Cars;
string DraggedSourceCar = x.Name;
e.Data.Properties.Add("myArgs", DraggedSourceCar);
}
private void GridInsideDatatemplateOfTargetListview_Drop(object sender, DragEventArgs e)
{
var x = sender as Grid;
var y = x.DataContext as Folders;
string toMoveFolderName = y.Name;
string DraggedSourceCar = e.DataView.Properties["myArgs"].ToString();
Debug.WriteLine(DraggedSourceCar + Environment.NewLine + toMoveFolderName );
}
private void TargetListview_DragOver(object sender, DragEventArgs e)
{
e.AcceptedOperation = DataPackageOperation.Copy;
}
You have to find out by yourself = DragEventArgs.GetPosition() in the destination drop, then the underlying item with smoe helper functions
public static object GetObjectAtPoint<ItemContainer>(this ItemsControl control, Point p)
where ItemContainer : DependencyObject
{
// ItemContainer - can be ListViewItem, or TreeViewItem and so on(depends on control)
ItemContainer obj = GetContainerAtPoint<ItemContainer>(control, p);
if (obj == null)
return null;
return control.ItemContainerGenerator.ItemFromContainer(obj);
}
public static ItemContainer GetContainerAtPoint<ItemContainer>(this ItemsControl control, Point p)
where ItemContainer : DependencyObject
{
HitTestResult result = VisualTreeHelper.HitTest(control, p);
if (result != null)
{
DependencyObject obj = result.VisualHit;
while (VisualTreeHelper.GetParent(obj) != null && !(obj is ItemContainer))
{
obj = VisualTreeHelper.GetParent(obj);
}
// Will return null if not found
return obj as ItemContainer;
}
else return null;
}
Did you checked this sample?
After some research I found what DragEventArgs contains an OriginalSource property with Name matches the name of target list when Drop event invoked.
I'm not checked it with folders and subfolders, but maybe OriginalSource will contain folder where item dropped.
<TextBlock Grid.Row="1" Margin="8,4"
VerticalAlignment="Bottom"
Text="All Items"/>
<ListView x:Name="SourceListView"
Grid.Row="2" Margin="8,4"
SelectionMode="Extended"
CanDragItems="True"
DragItemsStarting="SourceListView_DragItemsStarting"/>
<TextBlock Grid.Row="1" Grid.Column="1" Margin="8,4"
VerticalAlignment="Bottom"
Text="Selection"/>
<ListView x:Name="TargetListView"
Grid.Row="2" Grid.Column="1" Margin="8,4"
AllowDrop="True" CanReorderItems="True" CanDragItems="True"
DragOver="TargetListView_DragOver"
Drop="TargetListView_Drop"
DragItemsStarting="TargetListView_DragItemsStarting"
DragItemsCompleted="TargetListView_DragItemsCompleted"/>
And here is printscreen with fired breakpoint:
EDIT:
To get an item inside of TargetList you can do a trick.
I think you use DataTemplate to display custom list items ("folders"). You can see a sample below. As you see I add Grid_DragOver trigger.
<Page.Resources>
<DataTemplate x:Key="ListViewDataTemplate">
<Grid Margin="20,5" DragOver="Grid_DragOver"
BorderBrush="White" BorderThickness="5" AllowDrop="True">
<TextBlock Margin="10" LineHeight="40" FontSize="32" FontWeight="Bold"/>
</Grid>
</DataTemplate>
</Page.Resources>
This way Grid_DragOver will be invoked when mouse pointer enter inside the Grid in DataTemplate.
And if you use binding List<YourFolderClass> as data source, you'll get folder in DataContext. For example I used this:
var SampleData = new ObservableCollection<string>
{
"My Research Paper",
"Electricity Bill",
"My To-do list",
"TV sales receipt",
"Water Bill",
"Grocery List",
"Superbowl schedule",
"World Cup E-ticket"
};
You can see all code in gist.
I am really confused with wp8 listbox scrolling. with below simple code I am scrolling to the selected index (item), but it doesn't work.
lsbReadingChapter.SelectionChanged -= lsbReadingChapter_SelectionChanged;
_lastAyaSelectedIndex = startingAya;
lsbReadingChapter.ItemsSource = null;
lsbReadingChapter.ItemsSource = ds.getArabicTextWithTranslation(currentChapter);
lsbReadingChapter.SelectedIndex = startingAya;
lsbReadingChapter.UpdateLayout();
lsbReadingChapter.ScrollIntoView(lsbReadingChapter.SelectedItem);
lsbReadingChapter.SelectionChanged += lsbReadingChapter_SelectionChanged;
the selectedIndex is always greater than zero, but the listbox show the 1st item in the list and doesn't scroll.
Here is my xaml
ListBox x:Name="lsbReadingChapter" HorizontalAlignment="Stretch" Grid.Row="1" ScrollViewer.VerticalScrollBarVisibility="Visible" Width="480" SelectionChanged="lsbReadingChapter_SelectionChanged" Loaded="lsbReadingChapter_Loaded">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel HorizontalAlignment="Stretch" Width="480" Orientation="Vertical" Background="{Binding Converter={StaticResource AlternateRowConverter}}" >
<TextBlock Foreground="Black" Padding="20,0,30,0" TextWrapping="Wrap" HorizontalAlignment="{Binding HAlignment}" FontSize="{Binding ArabicFontSize}">
<Run Text="{Binding Aya}"/>
<Run Text="{Binding AyaID, StringFormat=﴿\{0\}﴾}" Foreground="Blue" FontSize="30"/>
</TextBlock>
<TextBlock Padding="20,0,30,0" Text="{Binding AyaTranslation}" Foreground="Black" FontSize="{Binding TranslationFontSize}" TextWrapping="Wrap" HorizontalAlignment="{Binding HAlignment}"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
I don't know why it doesn't scroll to the selected index?
Thanks!
Use ScrollIntoView function either by SelectedIndex or SelectedItem property.
lsbReadingChapter.ScrollIntoView(lsbReadingChapter.SelectedIndex);
or
lsbReadingChapter.ScrollIntoView(lsbReadingChapter.SelectedItem);
public static void ScrollToSelectedItem(ListBox control)
{
if (control.SelectedIndex != -1)
control.TopIndex = control.SelectedIndex;
}
Use
lsbReadingChapter.ScrollIntoView(lsbReadingChapter.Items[lsbReadingChapter.SelectedIndex]);
finally solved, by calling lsbReadingChapter.ScrollIntoView in grid load parent of Lisbox.
I have a list picker when clicking on the control to select another item it seems to look like it is going to work but is all white I can sometimes get it to select another item but cant see what is selected until you are off of it. This is how I have it set up. When I set it to full mode the name space is the only thing that shows not the actual name of the item. All I am trying to do is upon loading the view I need to load the listPicker with values.
<phone:PhoneApplicationPage.Resources>
<DataTemplate x:Name="PickerItemTemplate" >
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding TankTypeName}" Style="{StaticResource PhoneTextNormalStyle}"/>
</StackPanel>
</DataTemplate>
<DataTemplate x:Name="PickerFullModeItemTemplate">
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding TankTypeName}" Style="{StaticResource PhoneTextNormalStyle}" FontFamily="{StaticResource PhoneFontFamilyLight}"/>
</StackPanel>
</DataTemplate>
</phone:PhoneApplicationPage.Resources>
<!--ContentPanel - place additional content here-->
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
<TextBox Height="72" HorizontalAlignment="Left" Margin="0,50,0,0" Name="TextBoxProjectName" Text="" VerticalAlignment="Top" Width="456" />
<TextBlock Height="30" HorizontalAlignment="Left" Margin="12,28,0,0" Name="TextBlockProjectName" Text="Tank Name:" VerticalAlignment="Top" />
<toolkit:ListPicker Header="Tank Type:" ItemsSource="{Binding TankTypes}"
ItemTemplate="{StaticResource PickerItemTemplate}"
FullModeItemTemplate="{Binding PickerFullModeItemTemplate}"
SelectedItems="{Binding SelectedTankTypes,Mode=TwoWay}"
Height="100" HorizontalAlignment="Left"
Margin="6,144,0,0" Name="ListPickerTankType"
VerticalAlignment="Top" Width="444" >
</toolkit:ListPicker>
</Grid>
View Model
private List<TankType> _tankType;
private ObservableCollection<Object> _selectedTankType= new ObservableCollection<object>();
/// <summary>
/// Collection of Tank Type objects.
/// </summary>
public List<TankType> TankTypes
{
get
{
return _tankType;
}
set
{
if (value != _tankType)
{
_tankType = value;
NotifyPropertyChanged("TankType");
}
}
}
public ObservableCollection<object> SelectedTankTypes
{
get
{
return _selectedTankType;
}
set
{
if (_selectedTankType == value)
{
return;
}
_selectedTankType = value;
NotifyPropertyChanged("SelectedTankTypes");
}
}
This is a edit page so in the constructor of the view.
public TaskDetail()
{
InitializeComponent();
var tankTypeViewModel = new ViewModels.TankVewModel();
tankTypeViewModel.GetTankTypes();
ListPickerTankType.DataContext = tankTypeViewModel;
}
Revised OK I removed the height on the listpicker and now can see it made it bigger so the three items are there. I just cant seem to change the font color to black so I can see it when you click on the listpicker.
Figured it out. I needed to remove the height and set the foreground color to black.
I have a listbox in WPF databinded to a observablecollection
<ListBox Margin="0,0,-12,0" ItemsSource="{Binding ShopList}"
ScrollViewer.VerticalScrollBarVisibility="Auto"
Grid.Row="1"
Grid.ColumnSpan="2" KeyDown="ListBox_KeyDown" KeyUp="ListBox_KeyUp"
>
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" Margin="0,0,0,17" >
<!--Replace rectangle with image-->
<Rectangle Height="50" Width="50" Stroke="Black" StrokeThickness="6" Margin="12,0,9,0"/>
<StackPanel Width="Auto">
<TextBlock Text="{Binding Name}" TextWrapping="Wrap" Style="{StaticResource PhoneTextExtraLargeStyle}"/>
<TextBlock Text="{Binding Quantity}" TextWrapping="Wrap" Margin="12,-6,12,0" Style="{StaticResource PhoneTextSubtleStyle}"/>
</StackPanel>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
I then have a filter method I want called
private void ShopItemDay_Filter(object sender, FilterEventArgs e)
{
var item = e.Item as ShopItem;
e.Accepted = item.Day == 1;
}
But I cant find any properties on the Listbox to use a filter method like done here http://www.galasoft.ch/mydotnet/articles/article-2007081301.aspx
You need to create a 'view' on your collection. See the documentation for CollectionView.Filter. The framework will create a default view for all bound collections. You can add a filter as follows:
ICollectionView _customerView = CollectionViewSource.GetDefaultView(customers);
_customerView.Filter = CustomerFilter
private bool CustomerFilter(object item)
{
Customer customer = item as Customer;
return customer.Name.Contains( _filterString );
}
(From this tutorial);
As you can see in the article you linked to, the filter is not a property of the Control. It is a property of the CollectionViewSource which is a kind of wrapper around the collection. This wrapper allows for sorting, grouping and filtering.