I have maintains the collection for the Combo-Box in Window code behind, if I bound that collection via xaml means it’s unable to fetch the collection until externally set the DataContext for the window in code behind. can anyone help me to resolve this.
public ObservableCollection<string> Orders
{
get; set;
}
public MainWindow()
{
InitializeComponent();
Orders = new ObservableCollection<string>();
Orders.Add("1000");
Orders.Add("1001");
Orders.Add("1002");
Orders.Add("1003");
//this.DataContext = this;
}
<Grid DataContext="{Binding RelativeSource={RelativeSource AncestorType=Window}}">
<ComboBox Height="25" Width="100" ItemsSource="{Binding Orders}"></ComboBox>
</Grid>
You can set the DataContext for the Grid itself to use the same in various UI elements
You can bind datacontext of the window to itself.
That still will not work unless you move setting up the data though:
DataContext="{Binding RelativeSource={RelativeSource Self}}"
>
<Grid>
<ComboBox ItemsSource="{Binding Orders}"/>
</Grid>
</Window>
and
public ObservableCollection<string> Orders
{
get; set;
}
public MainWindow()
{
Orders = new ObservableCollection<string>();
Orders.Add("1000");
Orders.Add("1001");
Orders.Add("1002");
Orders.Add("1003");
InitializeComponent();
}
Related
I'm a newbie to TreeViews. In WPF style, I have a TreeView organized in three levels:
ReportName1
NetworkName1
PrinterName1
PrinterName2
NetworkName2
PrinterName3
PrinterName4
ReportName2
....
in the XAML, I am using Interaction behaviors to bind the TreeView SelectedItem to the ViewModel:
<TreeView ItemsSource="{Binding ReportTree}" >
<i:Interaction.Behaviors>
<tvb:TreeViewBehavior SelectedItem="{Binding SelectedTreeItem, Mode=TwoWay}" />
</i:Interaction.Behaviors>
At this point, all works well to send an item from the ReportTree when I select ANY item under the main report name. That is, if I select PrinterName2, then the SelectedTreeItem will be the main viewmodel for ReportName1.
What I need to know is, how can I tell that PrinterName2 is selected as opposed to PrinterName1?
My eventual goal is to allow selection of any leaf or branch in the tree and remove only that selected leaf or branch.
Is there a way to do this?
Thanks for any help on this.
Here is one option to solve this using a simple DataTemplate for the TreeView which contains a MouseBinding to call a select command on the parent ViewModel and pass the clicked item as a CommandParameter.
If your ViewModel looks something like this:
public class MainViewModel
{
public ObservableCollection<ItemViewModel> Items { get; private set; }
public ItemViewModel SelectedItem { get; set; }
public ICommand SelectItem { get; private set; }
public MainViewModel()
{
SelectItem = new LazyCommand<ItemViewModel>(ExecuteSelect);
Items = new ObservableCollection<ItemViewModel>();
}
private void ExecuteSelect(ItemViewModel item)
{
SelectedItem = item;
}
}
with a straightforward ViewModel for the items:
public class ItemViewModel
{
public ObservableCollection<ItemViewModel> Items { get; private set; }
public string Name { get; set; }
public ItemViewModel()
{
Items = new ObservableCollection<ItemViewModel>();
}
}
Then you can define a TreeView with an HierarchicalDataTemplate as ItemTemplate:
<TreeView ItemsSource="{Binding Items}">
<TreeView.ItemTemplate>
<HierarchicalDataTemplate ItemsSource="{Binding Items}" >
<TextBlock Text="{Binding Name}">
<TextBlock.InputBindings>
<MouseBinding MouseAction="LeftClick"
Command="{Binding DataContext.SelectItem, RelativeSource={RelativeSource FindAncestor, AncestorType=TreeView}}"
CommandParameter="{Binding}" />
</TextBlock.InputBindings>
</TextBlock>
</HierarchicalDataTemplate>
</TreeView.ItemTemplate>
</TreeView>
The crucial part is the binding to the TreeViews DataContext.SelectItemCommand from the MouseBinding of each item and passing the item in as a parameter. You can then handle the selection itself (setting SelectedItem, etc.) in the ViewModel.
I have a Listview and i want to bind it to a list declared on the same class(codebehind)
public ObservableCollection<Slot> ListViewList { get; set; }
<ListView x:Name="ListViewSlots" Margin="0,230,0,0" ItemsPanel="{DynamicResource ItemsPanelTemplate1}" ItemsSource="{Binding Path=UserControl.ListViewList}" >
But is not working, i tried setting the datacontext of the usercontrol to self and desnt works.
Have you tried setting the DataContext of the UserControl to the list, and then setting the ItemsSource of the ListView to that?
ie.
<ListView ItemsSource="{Binding}" >
Add to your Window
<Window ...
DataContext="{Binding RelativeSource={RelativeSource Self}}"
>
and then your ListView becomes
<Listview ItemsSource="{Binding ListViewList}">...
first you have to introduce your list to the resources of the class:
public List<string> ListViewList
{
get{ return (List<string> Resources["ListViewList"];}
set{ Resources["ListViewList"] = value;}
}
or use ObservableCollection:
private ObservableCollection<string> _listViewList = new ObservableCollection<string>();
public ObservableCollection<string> ListViewList { get { return _listViewList; } }
then in XAML, you can bind something to it:
<ListView>
<ItemsPanel
ItemsPanel="{DynamicResource ItemsPanelTemplate1}"
ItemsSource="{Binding ListViewList}"
/>
</ListView>
and as Joel said you need to set the DataContext of the entire window
(or just the block you're dealing with) to self:
<Window ...
DataContext="{Binding RelativeSource={RelativeSource Self}}"
>
I have a listbox in WPF that is in the Layout Root.
I also have a Frame that is in the Layout Root as well.
The listbox is composed of items that have a string(Name) and a framework element(UI).
How do I bind the frame's content to be the UI property of the listbox's selected item property?
If you need a codebehind, how would you do this in MVVM
I used a ContentControl instead of Frame since I had problem binding to Content property, I never got it to refresh after binding changed. I didn't do proper MVVM, Data should not be hosted inside the view.
XAML:
<Window.Resources>
<CollectionViewSource x:Key="CVS" Source="{Binding}" />
</Window.Resources>
<StackPanel DataContext="{Binding Source={StaticResource CVS}}">
<ListBox
ItemsSource="{Binding}"
IsSynchronizedWithCurrentItem="True"
DisplayMemberPath="Name">
</ListBox>
<ContentControl Content="{Binding Path=UI}" />
</StackPanel>
Code behind:
using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;
namespace BindDemo
{
public partial class Window1 : Window
{
public Window1()
{
InitializeComponent();
Data = new List<DataItem>();
Data.Add(new DataItem("TextBox", new TextBox(){ Text="hello" }));
Data.Add(new DataItem("ComboBox", new ComboBox()));
Data.Add(new DataItem("Slider", new Slider()));
DataContext = Data;
}
public List<DataItem> Data
{
get; private set;
}
}
public class DataItem
{
public DataItem(string name, FrameworkElement ui)
{
Name = name;
UI = ui;
}
public string Name { get; private set; }
public FrameworkElement UI { get; private set; }
}
}
It sounds as you want to display list of objects and details for selected object. If I am right, solution in MVVM may be following:
<ListView ItemsSource="{Binding ObjectsList}" IsSynchronizedWithCurrentItem="True" />
<ContentControl Content="{Binding ObjectsList}">
<ContentControl.ContentTemplate>
<DataTemplate>
<!-- details template -->
</DataTemplate>
</ContentControl.ContentTemplate>
</ContentControl>
I am trying to display a tooltip for an item generated by an ItemsControl that needs to pull data from conceptually unrelated sources. For example, say I have an Item class as follows:
public class Item
{
public string ItemDescription { get; set; }
public string ItemName { get; set; }
}
I can display the Item within an ItemsControl with a tooltip as follows:
<ItemsControl x:Name="itemsControl" ItemsSource="{Binding Items}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding ItemName}">
<TextBlock.ToolTip>
<ToolTip>
<TextBlock Text="{Binding ItemDescription}" />
</ToolTip>
</TextBlock.ToolTip>
</TextBlock>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
But say I have another property that can be accessed via the DataContext of the ItemsControl. Is there any way to do this from within the tooltip? E.g.,
<ItemsControl x:Name="itemsControl" ItemsSource="{Binding Items}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding ItemName}">
<TextBlock.ToolTip>
<ToolTip>
<Grid>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition />
</Grid.RowDefinitions>
<TextBlock Text="{Binding ItemDescription}" />
<TextBlock Grid.Row="1" Text="{Bind this to another property of the ItemsControl DataContext}" />
</Grid>
</ToolTip>
</TextBlock.ToolTip>
</TextBlock>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
The code for the test Window I used is as follows:
public partial class Window1 : Window
{
public Window1()
{
InitializeComponent();
List<Item> itemList = new List<Item>() {
new Item() { ItemName = "First Item", ItemDescription = "This is the first item." },
new Item() { ItemName = "Second Item", ItemDescription = "This is the second item." }
};
this.Items = itemList;
this.GlobalText = "Something else for the tooltip.";
this.DataContext = this;
}
public string GlobalText { get; private set; }
public List<Item> Items { get; private set; }
}
So in this example I want to show the value of the GlobalText property (in reality this would be another custom object).
To complicate matters, I am actually using DataTemplates and show two different types of objects within the ItemsControl, but any assistance would be greatly appreciated!
After an hour of hair pulling I have come to the conviction that you can't reference another DataContext inside a DataTemplate for a ToolTip. For other Bindings it is perfectly possible as other posters have proven. That's why you can't use the RelativeSource trick either. What you can do is implement a static property on your Item class and reference that:
<Window x:Class="ToolTipSpike.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window1" Height="300" Width="300"
Name="Root"
xmlns:ToolTipSpike="clr-namespace:ToolTipSpike">
<Grid>
<ItemsControl x:Name="itemsControl" ItemsSource="{Binding Items}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding ItemName}">
<TextBlock.ToolTip>
<ToolTip>
<Grid>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition />
</Grid.RowDefinitions>
<TextBlock Text="{Binding ItemDescription}" />
<TextBlock Grid.Row="1"
Text="{Binding Source={x:Static ToolTipSpike:Item.GlobalText},
Path=.}"
/>
</Grid>
</ToolTip>
</TextBlock.ToolTip>
</TextBlock>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</Grid>
</Window>
using System.Collections.Generic;
using System.Windows;
namespace ToolTipSpike
{
public partial class Window1 : Window
{
public List<Item> Items { get; private set; }
public Window1()
{
InitializeComponent();
var itemList = new List<Item>
{
new Item { ItemName = "First Item", ItemDescription = "This is the first item." },
new Item { ItemName = "Second Item", ItemDescription = "This is the second item." }
};
this.Items = itemList;
this.DataContext = this;
}
}
public class Item
{
static Item()
{
GlobalText = "Additional Text";
}
public static string GlobalText { get; set; }
public string ItemName{ get; set;}
public string ItemDescription{ get; set;}
}
}
Second attempt
Ok, the Relative Source Binding doesn't work in this case. It actually works from a data template, you can find many examples of this on the Internets. But here (you were right, David, in your comment) ToolTip is a special beast that is not placed correctly in the VisualTree (it's a property, not a control per se) and it doesn't have access to the proper name scope to use relative binding.
After some more searching I found this article, which describes this effect in details and proposes an implementation of a BindableToolTip.
It might be an overkill, because you have other options -- like using a static property on a class (as in Dabblernl's response) or adding a new instance property to your Item.
First attempt :)
You should consult with the Relative Source Binding types (in this cheat sheet for example):
So your binding will look somehow similar to this:
{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ItemsControl}}, Path= GlobalText}
Almost correct Yacoder, and guessed way wrong there Dabblernl ;)
Your way of thinking is correct and it is possible to reference the DataContext of your ItemsControl
You are missing the DataContext property in path:
{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ItemsControl}}, Path=DataContext.GlobalText}
Second attempt ;)
http://blogs.msdn.com/tom_mathews/archive/2006/11/06/binding-a-tooltip-in-xaml.aspx
Here is an article with the same problem. They can reference the DataContext of their Parent control by the PlacementTarget property:
<ToolTip DataContext=”{Binding RelativeSource={RelativeSource Self},Path=PlacementTarget.Parent}”>
If you would place the DataContext on a deeper level, you avoid changing your Item DataContext
A second suggestion (Neil and Adam Smith) was that we could use PlacementTarget in the binding. This is nice, as I am actually inheriting the DataContext already from the page that hosts the DataControl, and this would allow the ToolTip to gain access back to the origial control. As Adam noted, though, you have to be aware of the parent/child structure off your markup:
This is a case where I think it's conceptually more appropriate to do this in the view model than it is in the view anyway. Expose the tooltip information to the view as a property of the view model item. That lets the view do what it's good at (presenting properties of the item) and the view model do what it's good at (deciding what information should be presented).
I had a very similar problem and arrived at this question seeking answers. In the end I came up with a different solution that worked in my case and may be useful to others.
In my solution, I added a property to the child item that references the parent model, and populated it when the children were generated. In the XAML for the ToolTip, I then simply referenced the property from the parent model on each element and set the DataContext to the parent model property.
I felt more comfortable with this solution than creating proxy elements in XAML and referencing them.
Using the example code for this question, you would do the following. Note I have not tested this scenario in a compiler, but have done so successfully implemented this solution in the code for my own scenario.
Item:
public class Item
{
public List<Item> Parent { get; set; }
public string ItemDescription { get; set; }
public string ItemName { get; set; }
}
Window:
public partial class Window1 : Window
{
public Window1()
{
InitializeComponent();
List<Item> itemList = new List<Item>();
itemList.Add(new Item() { Parent = this, ItemName = "First Item", ItemDescription = "This is the first item." });
itemList.Add(new Item() { Parent = this, ItemName = "Second Item", ItemDescription = "This is the second item." });
this.Items = itemList;
this.GlobalText = "Something else for the tooltip.";
this.DataContext = this;
}
public string GlobalText { get; private set; }
public List<Item> Items { get; private set; }
}
XAML:
<ItemsControl x:Name="itemsControl" ItemsSource="{Binding Items}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding ItemName}">
<TextBlock.ToolTip>
<ToolTip>
<Grid>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition />
</Grid.RowDefinitions>
<TextBlock Text="{Binding ItemDescription}" />
<TextBlock Grid.Row="1" DataContext={Binding Parent} Text="{Bind this to aproperty of the parent data model}" />
</Grid>
</ToolTip>
</TextBlock.ToolTip>
</TextBlock>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
I have one Listbox and applied one DataTemplate like this
<ListBox>
<ListBox.ItemTemplate>
<Grid>
<TextBlock Text="{Binding Path=Name}" Grid.Row=0/>
<ComoboBox Name="test"
DisplayMemberPath="Country"
SelectedValuePath="Country_ID">
</Grid>
How will I load ItemSource to this ComboBox dynamically based on each item selected in the ListBox? Iam new to WPF... pls help with your valuable suggestions.
<ListBox>
<ListBox.ItemTemplate>
<Grid>
<TextBlock Text="{Binding Path=Name}" Grid.Row=0/>
<ComoboBox Name="test"
DataContent="{Binding RelativeSource={RelativeSource AncestorType=ListBox}}"
ItemsSource="{Binding}"
DisplayMemberPath="Country"
SelectedValuePath="Country_ID">
</Grid>
Now your combocbox is always have the same itemssource as the parent listbox.
One way to do this is to bind the ItemsSource of your ComboBox to the SelectedValue property of the ListBox. For this to work the ListBox needs to be bound to a collection of items that contains a list of items that the ComboBox will bind to.
<ListBox
x:Name="CategoryList"
ItemsSource="{Binding Path=MasterList,
RelativeSource={RelativeSource AncestorType=Window}}"
DisplayMemberPath="MasterProperty"
SelectedValuePath="Details"
/>
<ComboBox
ItemsSource="{Binding Path=SelectedValue, ElementName=CategoryList}"
DisplayMemberPath="DetailProperty"
Grid.Row="1"
/>
In this example I have created a public property in the code behind of the window that exposes a list of objects containing the Details collection.
public List<Master> MasterList { get; set; }
public class Master
{
public string MasterProperty { get; set; }
public List<Detail> Details { get; set; }
}
public class Detail
{
public string DetailProperty { get; set; }
}