What I want it to bind TextBoxes to my dictionaries values.
I could find some posts about it already but :
One means having my dictionary as context :
XML :
<TextBox x:Name="FirstLine" Text="{Binding Path=[FirstLine]}"/>
XAML :
public ImportProfilesOptions()
{
InitializeComponent();
contexte = new ViewModelImportProfilesOptions();
DataContext = contexte.ParamsData;
}
The other one using Templates :
<ItemsControl x:Name="dictionaryItemsControl" ItemsSource="{Binding dictionary}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Key}" />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
But I would like to use it, without using Templates (I need to add in labels some translates I take from properties), and without setting my dictionary as context. Something like that :
XML
<TextBox x:Name="FirstLine" Text="{Binding Path=ParamsDate[FirstLine]}" />
XAML
contexte = new ViewModelImportProfilesOptions();
DataContext = contexte;
But then, binding is not working anymore.
You can't do this out of the box, though you could create your own converter I guess:
public class SomeFunkyConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
if (!(value is Dictionary<string,string> dictionary))
return null;
if (!(parameter is string key))
return null;
return !dictionary.TryGetValue(key, out var result) ? null : result;
}
// ill leave this up to you
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
=> throw new NotSupportedException();
}
Usage
<TextBlock Text="{Binding Path=ParamsDate,
ElementName=TextBox,
Converter={StaticResource SomeFunkyConverter},
ConverterParameter='Bob'}"/>
Note : Completely untested
Related
How can I bind an inverted value of a bool in my xaml?
I know, I know, there are a lot of q&a about this, but there aren't any about a specific case: when the converter is in a view model and the radio button in a user control.
how can I correctly refer to the main window view model data context? In other case I used the code I've posted, but in this case I don't get how to use it.
UPDATE CODE:
namespace ***.ViewModel
{
[ValueConversion(typeof(bool), typeof(bool))]
public class InverseBooleanConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter,
System.Globalization.CultureInfo culture)
{
if (targetType != typeof(bool))
throw new InvalidOperationException("The target must be a boolean");
return !(bool)value;
}
public object ConvertBack(object value, Type targetType, object parameter,
System.Globalization.CultureInfo culture)
{
throw new NotSupportedException();
}
}
class MainWindowViewModel : MyClass.UtilityClasses.ViewModelBase
{
public MainWindowViewModel(){
SaveCommand = new DelegateCommand(SaveData, CanSave );
UndoCommand = new DelegateCommand(UndoActions, CanSave);
[...]
}
....
}
ANOTHER CODE UPDATE:
In my xaml, I have a devexpress GridControl where I list my observableCollection from db. When I click one element, a layout group is populated with the relative data.
In this layout group, I have:
<StackPanel Margin="0" Orientation="Horizontal" VerticalAlignment="Center" HorizontalAlignment="Left">
<RadioButton Content="{DynamicResource Locale}" Margin="10,0,0,0" x:Name="rd_LOCALE" VerticalAlignment="Center" IsChecked="{Binding Path=REMOTO, Converter={StaticResource InverseBooleanConverter}}" GroupName="Location" Panel.ZIndex="9" TabIndex="10" />
<RadioButton Content="{DynamicResource Remoto}" Margin="10,0,6,0" x:Name="rd_REMOTO" VerticalAlignment="Center" IsChecked="{Binding REMOTO}" GroupName="Location" Panel.ZIndex="10" TabIndex="11" Tag="PRISMA" />
</StackPanel>
WhenI change from one record to another, the converter gives me error... why? It fails the "if (targetType != typeof(bool))" row. So I tried to change that like:
if (value.getType() != typeof(bool))
but in this way, without fails nothing in the code, it put the wrong value in the radiobutton!
You need to make sure that the value converter is referenced in the XAML
<UserControl.Resources>
<myproject:InverseBooleanConverter x:Key="InverseBooleanConverter" />
</UserControl.Resources>
where my project is the namespace in which the value converter class is defined
I am working on a windows universal app and I'm trying to work out data binding.
I have a listview which has an item template and data template in which a property of a custom class is bound.
<ListView>
<ListView.ItemTemplate>
<DataTemplate>
<Textblock Text="{Binding Name}"/>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
This works fine an displays the names all instances of my custom class in the ObservableCollection I bind to the listview. I was wondering however if there is some way of modifying what is being bound before it is bound without changing the class itself.
I'm trying to bind a capitalisation of the string property Name so if the name was Test I want to bind TEST instead. Currently the way I'm doing this is to have a separate property called NameLabel which I populate like this
NameLabel = Name.ToUpper();
However this seems very messy and I was wondering if there's a neater way of doing it without creating a separate property?
You can use a Converter.
Create a StringToUpper.cs File with a StringToUpper Class which inherits form IValueConverter:
public class StringToUpper: IValueConverter
{
public object Convert(object value, Type targetType,
object parameter, CultureInfo culture)
{
var valueString = value.ToString();
if (!string.IsNullOrEmpty(valueString))
{
return valueString.ToUpper();
}
return string.Empty;
}
public object ConvertBack(object value, Type targetType,
object parameter, CultureInfo culture)
{
// do nothing.
}
}
Add the resource of your created Converter:
...
xmlns:converter="clr-namespace:StringToUpper"
...>
<Window.Resources>
<converter:StringToUpper x:Key="StringToUpperConverter" />
</Window.Resources>
Add the converter:
<Textblock Text="{Binding Name, Converter={StaticResource StringToUpperConverter}}"/>
Here is a good Tutorial about Converters in WPF.
You could create a converter, that turns the value of a property into a form desired for the view (in your case, a simple capitalisation of the string).
Your converter class might look like this:
public class StringToUpperStringConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
var valueString = value.ToString();
if (!string.IsNullOrEmpty(valueString))
{
return valueString.ToUpper();
}
return string.Empty;
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotImplementedException();
}
}
Your xaml might have this defined in the resource section:
<converters:StringToUpperStringConverter x:Key="StringToUpperStringConverter" />
And your binding would then look like this:
<Textblock Text="{Binding Name, Converter={StaticResource StringToUpperStringConverter}}"/>
I want to convert the localization meta tag e.g. en-US to the display name, in this case English. The meta tag is stored in a ObservableCollection because it will be modified on runtime. I want to bind the display name to a combo box.
ComboBox:
<ComboBox Grid.Column="1" Grid.Row="1" Width="200" VerticalAlignment="Center" HorizontalAlignment="Center" SelectedIndex="0" ItemsSource="{Binding Path=ServerData.AvailableTemplateLanguages}">
<ComboBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding, Converter=LanguageTagToNameConverter}" FontSize="12"/>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
Converter:
class LanguageTagToNameConverter : IValueConverter
{
public object Convert(object value,
Type targetType,
object parameter,
CultureInfo culture)
{
return CultureInfo.GetCultureInfo(value.ToString()).DisplayName;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
ObservableCollection:
public class ServerDataObj : ModelBase
{
private ObservableCollection<string> _availableTemplateLanguages = new ObservableCollection<string> { "de-DE", "en-US" };
public ObservableCollection<string> AvailableTemplateLanguages
{
get
{
return _availableTemplateLanguages;
}
set
{
_availableTemplateLanguages = value;
OnPropertyChanged("AvailableTemplateLanguages");
}
}
}
Unfortunately this approach does not work.
You need to put converter into resources:
<Window>
<Window.Resources>
<LanguageTagToNameConverter x:Key="convLang"/>
</Window.Resources>
...
<TextBlock Text="{Binding, Converter={StaticResource convLang}}"/>
I have a listbox that is populated from a datatable. I want each item to have a specific image on listbox, but I want to set the image depending of an id that each item has.
for example , I have :
Products
Orange
Apple
ID
1
2
and the images are named: Item.1.png , Item.2.png
So, in my listbox,where I have apple, I will have next to it the image named: Item.2.png.
My problem is that I don't know how could I do a conditional binding . I don't want to have on my template hundreds of lines that are doing this for each item. I need to do this using a condition, like : if(product.id==1), Image.Source=Item.1.png.
Is there any way to do this in wpf?
It sounds to me like you need an IdToImageConverter that will decides which Image should be shown dependant on the value of the Id property. Something like this should do the trick:
[ValueConversion(typeof(int), typeof(ImageSource))]
public class IdToImageConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
if (value.GetType() != typeof(int) || targetType != typeof(ImageSource)) return false;
int id = (int)value;
if (id < 0) return DependencyProperty.UnsetValue;
string imageName = string.Empty;
switch (id)
{
case 1: imageName = "Item.1.png"; break;
case 2: imageName = "Item.2.png"; break;
}
if (imageName.IsEmpty()) return null;
return string.Format("/AppName;component/ImageFolderName/{0}", imageName);
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
return DependencyProperty.UnsetValue;
}
You could then use it in your ListBox.ItemTemplate something like this:
<YourConvertersXmlNamespacePrefix:IdToImageConverter x:Key="IdToImageConverter" />
...
<ListBox ItemsSource="{Binding Items}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<Image Source="{Binding Id, Converter={StaticResource
IdToImageConverter}}" />
<TextBlock Text="{Binding Name}" Margin="5,0,0,0" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
As I understand your question, every object in the listbox has an ID property, where you want the image to be item.ID.png.
You could use a converter in your binding to do this. So in your listbox template, you can have something like:
// ... Listbox template
<Image Source={Binding pathToItemID, Converter={StaticResource MyConverter}/>
// ... Remaining ListBox template
You will need to add the converter to the UserControl's resources:
<UserControl.Resources>
<xmlnsPointingToConverter:MyConverter x:Key="MyConverter"/>
</UserControl.Resources>
Then add a MyConverter class which implements IValueConverter:
public class MyConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
return string.Format("item.{0}.png", value);
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotImplementedException();
}
}
I need to make some complex binding in XAML. I have a DependencyProperty typeof(double); let's name it SomeProperty. Somewhere in XAML code of my control, I need to use the whole SomeProperty value, somewhere only a half, somewhere SomeProperty/3, and so on.
How can I do something like:
<SomeControl Value="{Binding ElementName=MyControl, Path=SomeProperty} / 3"/>
:)
Looking forward.
Use a division ValueConverter:
public class DivisionConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
int divideBy = int.Parse(parameter as string);
double input = (double)value;
return input / divideBy;
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotSupportedException();
}
}
<!-- Created as resource -->
<local:DivisionConverter x:Key="DivisionConverter"/>
<!-- Usage Example -->
<TextBlock Text="{Binding SomeProperty, Converter={StaticResource DivisionConverter}, ConverterParameter=1}"/>
<TextBlock Text="{Binding SomeProperty, Converter={StaticResource DivisionConverter}, ConverterParameter=2}"/>
<TextBlock Text="{Binding SomeProperty, Converter={StaticResource DivisionConverter}, ConverterParameter=3}"/>