I am trying to bind an Enum
to a ComboBox
. I have seen a lot of people using an ObjectDataProvider
but I cannot seem to access it. I have also noticed that some people are using it within a Window.Resources
, rather than Page.Resources
but I cannot find how it is used on Page.Resources
. I have been searching for a solution for hours.
What I have so far:
XAML
<Page
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:Sports;assembly=Sports"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:ViewModel="using:Sports.ViewModel"
xmlns:model="using:Sports.Model"
xmlns:system="using:System"
x:Class="Sports.MainPage"
mc:Ignorable="d">
<Page.DataContext>
<ViewModel:CreateSubsVM/>
</Page.DataContext>
<Page.Resources>
<ObjectDataProvider></ObjectDataProvider>
</Page.Resources>
</Grid>
</Page>
C#
public enum SubsAmount
{
[Display(Description = "One Year")]
Oneyear = 0,
[Display(Description = "Two Years")]
TwoYears = 1,
[Display(Description = "Three Years")]
ThreeYears = 2
}
public class ComboboxConverter: IValueConverter
{
public string GetEnumValues(Enum enumObj)
{
DisplayAttribute attribute = enumObj.GetType().
GetRuntimeField(enumObj.ToString()).
GetCustomAttributes(typeof(SubsAmount), false).
SingleOrDefault() as DisplayAttribute;
return attribute == null ? enumObj.ToString() : attribute.Description;
}
public object Convert(object value, Type targetType, object parameter, string language)
{
return GetEnumValues((Enum) value);
}
public object ConvertBack(object value, Type targetType, object parameter, string language)
{
return Enum.ToObject(targetType, value);
}
}
Here is an example with a page object(according to the MSDN documentation there is no any restriction to use the ObjectDataProvider with page):
Update #1
Xaml
<Page x:Class="PageBasedApp.MyPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:pageBasedApp="clr-namespace:PageBasedApp"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300"
Title="MyPage">
<Page.Resources>
<ObjectDataProvider x:Key="Gestures" MethodName="GetValues" ObjectType="{x:Type ApplicationGesture}">
<ObjectDataProvider.MethodParameters>
<x:Type TypeName="ApplicationGesture" />
</ObjectDataProvider.MethodParameters>
</ObjectDataProvider>
<ObjectDataProvider x:Key="SubAmounts" MethodName="GetShortListOfApplicationGestures" ObjectType="{x:Type pageBasedApp:DisplayAttributeBasedObjectDataProvider}">
<ObjectDataProvider.MethodParameters>
<x:Type TypeName="pageBasedApp:SubsAmount" />
</ObjectDataProvider.MethodParameters>
</ObjectDataProvider>
</Page.Resources>
<Grid>
<StackPanel HorizontalAlignment="Center" VerticalAlignment="Center" >
<Label Content="All Gestures:"/>
<ComboBox ItemsSource="{Binding Source={StaticResource Gestures}}" Width="150"/>
<Label Content="Sub Amounts:"/>
<ComboBox ItemsSource="{Binding Source={StaticResource SubAmounts}}" Width="150"/>
</StackPanel>
</Grid>
Here is a custom Data provider code
public class DisplayAttributeBasedObjectDataProvider : ObjectDataProvider
{
public object GetEnumValues(Enum enumObj)
{
var attribute = enumObj.GetType().GetRuntimeField(enumObj.ToString()).
GetCustomAttributes(typeof(DisplayAttribute), false).
SingleOrDefault() as DisplayAttribute;
return attribute == null ? enumObj.ToString() : attribute.Description;
}
public List<object> GetShortListOfApplicationGestures(Type type)
{
var shortListOfApplicationGestures = Enum.GetValues(type).OfType<Enum>().Select(GetEnumValues).ToList();
return
shortListOfApplicationGestures;
}
}
Attribute code and enum:
[AttributeUsage(AttributeTargets.Field, AllowMultiple = false)]
public class DisplayAttribute : Attribute
{
public DisplayAttribute(string displayName)
{
Description = displayName;
}
public string Description { get; set; }
}
public enum SubsAmount
{
[Display("One Year")]
Oneyear = 0,
[Display("Two Years")]
TwoYears = 1,
[Display("Three Years")]
ThreeYears = 2
}
PS You don't need any converters here. Regards.
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