List box is not binded just a Combobox replacement (values are exposed)
Xaml
<ListBox SelectionChanged="LBX_AddTaskOptions_SelectionChanged" HorizontalAlignment="Left" Margin="19,29,0,0" Name="LBX_AddTaskOptions" VerticalAlignment="Top" Width="125" FontWeight="Bold" Background="Beige">
<ListBoxItem Background="Beige" FontWeight="Bold" v>
<StackPanel Orientation="Horizontal">
<TextBlock Text="internet"></TextBlock>
<Image Source="Images\IE_BlackRed.png" Height="30"></Image>
</StackPanel>
</ListBoxItem>
<ListBoxItem Background="Beige" FontWeight="Bold">
<StackPanel Orientation="Horizontal">
<TextBlock Text="localFolder"></TextBlock>
<Image Source="Images\Folder_Black.png" Height="30"></Image>
</StackPanel>
</ListBoxItem>
</ListBox>
CodeBehind
private void LBX_AddTaskOptions_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
var SelItm = LBX_AddTaskOptions.SelectedItem.ToString();
MessageBox.Show(Sel);
}
i have searched for that question, though answers are only for complex issues
as i am fresh .net Developer, i know all methods to extract DDL text/value
i even made extentions , though couldn't figure how to do this simple value extraction
shouldn't it be simple ?
messageBox shows the name of control (:
This isn't quite the right approach for XAML. You don't want to list out the markup for each item -- instead, use an ItemTemplate to define how it should look, and use bindings to render the actual item:
<ListBox SelectionChanged="LBX_AddTaskOptions_SelectionChanged" Name="LBX_AddTaskOptions">
<ListBox.ItemTemplate>
<ListBoxItem Background="Beige" FontWeight="Bold" v>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding}" />
<Image Source="Images\IE_BlackRed.png" Height="30" />
</StackPanel>
</ListBoxItem>
</ListBox.ItemTemplate>
</ListBox>
Bind the ListBox ItemsSource to the model data itself (ie, the array of strings in this case). Now, eventually you'll probably want to use a view model, but you can also add the items from code behind on load:
string[] ListBoxItems = new string[] { "internet", "local folder" };
LBX_AddTaskOptions.ItemsSource = ListBoxItems;
This should result in SelectedValue giving you the correct value.
Footnote -- you could get the selected value using the markup you've written out in the question -- but it would be ugly and would defeat the whole purpose of XAML. You'd need to cast SelectedItem to a ListBoxItem, then get its child and cast that to a StackPanel, get its children, etc, you get the idea. And then, of course, if the markup changes at all, the code you just wrote is no longer valid.
The item that you are getting in your selected value is a ListBoxItem with a control inside it. If you want to extract the value like the text then you have to do this
private void LBX_AddTaskOptions_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
var SelItm = LBX_AddTaskOptions.SelectedItem as ListBoxItem;
var StackPanel = SelItm.Content as StackPanel;
foreach (var child in StackPanel.Children)
{
if(child is TextBlock)
{
MessageBox.Show((child as TextBlock).Text);
}
}
}
You have to sort of dig into the control to get the actual text. There are a lot of ways to get the value but this is the pretty basic one.
Calling ToString() method will just convert the current object as a string which is a ListBoxItem.
Related
I'm developing a WPF app using MVVM pattern with Caliburn.Micro
I have a config file that contains positions of where XAML elements should be inside of a StackPanel
# in this case RU_ELEMENT should be at the top, EN_ELEMENT second and DE_ELEMENT last
EN_ELEMENT = 1
DE_ELEMENT = 2
RU_ELEMENT = 0
This seems to be pretty basic yet I'm unable to find a way to do this. I found this thread: change the children index of stackpanel in wpf but changing it this way seems to be too complicated for what I am after. I just need to set an index of an element from a variable. I feel like there should be a much simpler way. I'm also ok with using some other, perhaps more appropriate layout panel than StackPanel.
XAML:
<!-- Language1 -->
<TextBlock Text="English" Foreground="DarkGray" FontSize="16"/>
<TextBox
VerticalAlignment="Top"
Height="150"
Text="{Binding SelectedItem.ValueEN, UpdateSourceTrigger=PropertyChanged}"
cm:Message.Attach="[Event GotFocus] = [Action FocusedTextBox('english')]" />
<!-- Language2 -->
<TextBlock Text="German" Foreground="DarkGray" FontSize="16"/>
<TextBox
VerticalAlignment="Top"
Height="150"
Text="{Binding SelectedItem.ValueDE, UpdateSourceTrigger=PropertyChanged}"
cm:Message.Attach="[Event GotFocus] = [Action FocusedTextBox('german')]" />
On a side note: I find WPF and C# in general to have much less discussions and "how to" guides than all of my previous languages (Java, Python, JS) so researching things online is usually a dead end for me. I'm not sure to why that is since C# is a very popular language but I'm really struggling with finding help online.
A solution could be to use an ItemsControl that would host the xaml elements. You can bind the items like <ItemsControl ItemsSource="{Binding ListOfItems} ...
Then you could easily sort the items in the corresponding ViewModel. Like so:
public BindableCollection<YourElement> ListOfItems {get;set;}
...
ListOfItems.Sort()
Note that YourElement class should have a comparator.
EDIT: As per request I'll explain it more detailed:
In your Xaml you have to declare a ItemsControl like so:
<ItemsControl ItemsSource="{Binding ListOfItems}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Text="{Binding Language}" Foreground="DarkGray" FontSize="16"/>
<TextBox
VerticalAlignment="Top"
Height="150"
Text="{Binding TextValue, UpdateSourceTrigger=PropertyChanged}"
cm:Message.Attach="[Event GotFocus] = [Action FocusedTextBox($this)]" />
</StackPanel>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
And in your backend you should first create a class that's going to represent your item in the ItemsControl. For example:
public Class MyItem{
public string Language {get;set;}
public string TextValue {get;set;}
}
Finally in your ViewModel you'll need to create the list of items that you bind with the ItemsControl like so:
public BindableCollection<MyItem> ListOfItems {get;set;}= new BindableCollection<MyItem>();
//here you can add them in the order that is specified by the config file
public void LoadItems(){
ListOfItems.Add(new MyItem{Language="English"});
ListOfItems.Add(new MyItem{Language="Russian"});
ListOfItems.Add(new MyItem{Language="German"});
}
public void FocusedTextBox(MyItem item){
//do here whatever you want
}
I have a list box
<Label Content="Report" HorizontalAlignment="Left" Height="47" Margin="36,75,0,0" VerticalAlignment="Top" Width="63"/>
<ListBox x:Name="ListBox1" HorizontalAlignment="Left" Height="121" Margin="84,75,0,0" VerticalAlignment="Top" Width="102" SelectionChanged="ListBox_SelectionChanged" SelectedIndex="-1">
<ListBox Height="100" Width="100" SelectionChanged="ListBox_SelectionChanged_1">
<ListBoxItem x:Name="ListBoxFAT" Content="FAT"/>
<ListBoxItem x:Name="ListBoxNUMI" Content="NUMI"/>
<ListBoxItem x:Name="ListBoxSSID" Content="SSID"/>
<ListBoxItem x:Name="ListBoxFact" Content="FACT"/>
</ListBox>
</ListBox>
This was created by dragging the listbox icon from the tool bar. I added items and their values.
Now I am trying to just get the text value of the selected item.
private void ListBox_SelectionChanged_1(object sender, SelectionChangedEventArgs e)
{
string text = (string)ListBox1.SelectedValue;
MessageBox.Show(text);
I have also tried SelectedItem
string text = (string)ListBox1.SelectedItem;
But the message box is always blank.
This should be simple, but I have been working on it for hours, and trying every suggestion or answer on stackoverflow. Most suggestions do not even compile. For example:
string selected = listBox1.GetItemText(listBox1.SelectedValue);
Will not compile. GetItemText is not found. I am using Visual Studio 17. "'ListBox does not contain a definition for 'GetItemText'..."
Any thoughts? Please advise. Thanks.
Thanks for the comment, Charles. I did that.
Playing further, now I get
System.InvalidCastException: 'Unable to cast object of type 'System.Windows.Controls.ListBoxItem' to type 'System.String'.'
string text = (string)ListBox1.SelectedItem;
As indicated by Charles May, your XAML shows that your ListBox is within another ListBox, which is why you're getting errors being raised..
The event being called "ListBox_SelectionChanged_1" is bound to the ListBox object inside ListBox1, which is unnamed.
I believe that the behaviour you are looking for would be fixed like this:
XAML:
<Label Content="Report" HorizontalAlignment="Left" Height="47" Margin="36,75,0,0" VerticalAlignment="Top" Width="63"/>
<ListBox x:Name="ListBox1" HorizontalAlignment="Left" Height="121" Margin="84,75,0,0" VerticalAlignment="Top" Width="102" SelectionChanged="ListBox_SelectionChanged" SelectedIndex="-1">
<ListBoxItem x:Name="ListBoxFAT" Content="FAT"/>
<ListBoxItem x:Name="ListBoxNUMI" Content="NUMI"/>
<ListBoxItem x:Name="ListBoxSSID" Content="SSID"/>
<ListBoxItem x:Name="ListBoxFact" Content="FACT"/>
</ListBox>
Code Behind:
private void ListBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
string text = ((sender as ListBox)?.SelectedItem as ListBoxItem)?.Content.ToString();
MessageBox.Show(text);
}
Or at least something close to this solution.
In the markup, SelectedIndex is set to -1 which means there is no selection. In this case, SelectedValue and SelectedItem both return null. You can solve this either by setting SelectedIndex to a value between 0 and 3 or by preparing your code to cope with a null value in SelectedValue and SelectedItem, e.g.
string text = (ListBox1.SelectedItem as ListBoxItem)?.Content?.ToString();
This won't raise an error so that the user can select an item afterwards. With a selection, the text should be displayed as expected.
something that I thought would be simple is turning out not to be, or I'm just not thinking hard enough :)
I have a page which I navigate to, in the OnNavigateTo event I set the SelectedIndex of a ListPicker and that works fine.
If I then touch the ListPicker and select a new value the OnNavigateTo event is fired again and the new value is overridden by the original value.
My initial thought was to simply check the parent page name and if it was the ListPicker then skip the initial setting but I can't seem to find where to get the parent page name from.
Any clues? or a better way I should be handling this?
Here's the XAML:
<toolkit:ListPicker x:Name="Status" Margin="10,549,163,-97" Header="Status" FullModeHeader="Status" ExpansionMode="FullScreenOnly" BorderBrush="Black" Foreground="Black" Grid.ColumnSpan="2" Visibility="Visible">
<toolkit:ListPicker.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding}" />
</DataTemplate>
</toolkit:ListPicker.ItemTemplate>
<toolkit:ListPicker.FullModeItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding}"
FontSize="43"
FontFamily="{StaticResource PhoneFontFamilyLight}"/>
</DataTemplate>
</toolkit:ListPicker.FullModeItemTemplate>
</toolkit:ListPicker>
And here's the Loaded event:
private void AddNote_Loaded(object sender, RoutedEventArgs e)
{
this.TicketStatus.ItemsSource = ticketStatus();
string st;
if (NavigationContext.QueryString.TryGetValue("status", out st))
{
tStatus = st;
TicketStatus.SelectedIndex = GetStatus(tStatus);
}
}
Ok, worked around it but creating my own page list and manually adding and removing the pages I want to check for. Bit of a hack but it works :)
Hej
I want to create a standard holdevent. When you hold an element, there would appear some options you could chose like a new list.
How do you create this, is it just simply done with a popup or is there a smarter way?
Extra
After finding the answer, see answer below, some nice info is:
Put the context creation inside the hold event.
Then you can change to different contextmenus depending on the item. You can get the item that was holded by the following
private void StackPanel_Hold(object sender, GestureEventArgs e)
{
ItemViewModel itemViewModel = (sender as StackPanel).DataContext as ItemViewModel;
string t = itemViewModel.LineOne;
}
And
<ListBox x:Name="MainListBox" Margin="0,0,-12,0" ItemsSource="{Binding Items}" >
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Margin="0,0,0,17" Height="78" Hold="StackPanel_Hold">
<TextBlock Text="{Binding LineOne}" />
<TextBlock Text="{Binding LineTwo}" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
A good link for easy implementation is also youtube link below, replicated here :
Youtube
A ContextMenu is one option..
http://blogs.msdn.com/b/msgulfcommunity/archive/2013/05/19/windows-phone-toolkit-context-menu-getting-selected-item-within-a-long-list-selector.aspx
I have a note application with a ListBox control, which lists all the available notes from the ObservableCollection<Note> Notes. class Note has attributes like
String Title;
bool Has_Reminder;
DateTime Reminder_Date;
What I want is that the TextBlock element, which shows the Reminder_Date, is only shown, if Has_Reminder is true. But I do not know how to access this attribute from my custom control NoteListItem. Its this.DataContext attribute is null, but the control still properly displays the Note's bound attributes handed down by the ListBox ItemsSource. How can I achieve that?
Thanks for your help.
I tried to read the attributes in the constructor, which did not work:
public NoteListItem()
{
InitializeComponent();
Note this_note = LayoutRoot.DataContext as Note; // turns out, this_note is null
if (!this_note.Has_Reminder)
Reminder_Info.Visibility = System.Windows.Visibility.Collapsed;
}
NoteListItem control
<Grid x:Name="LayoutRoot" >
<TextBlock x:Name="Title" Text="{Binding Title}" />
<TextBlock x:Name="Reminder_Date" Text="{Binding Reminder_Date}" />
</Grid>
NoteList control:
<ListBox x:Name="NoteListBox" ItemsSource="{Binding Notes}" >
<ListBox.ItemTemplate>
<DataTemplate>
<local:NoteListItem />
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
Do you know how to use a converter? Your converter would convert a bool to a Visibility, then you can bind the TextBlock's Visibility to Has_Reminder:
<TextBlock x:Name="Reminder_Date" Text="{Binding Reminder_Date}" Visibility="{Binding Has_Reminder, Converter={...}}"/>
This might help: http://www.jeff.wilcox.name/2008/07/visibility-type-converter/