如何对ObservableCollection进行排序<KeyValuePair<int, string>

Question

I've an ObservableCollection<KeyValuePair<int, String>>() named TestList binded on a Textbox and I want to sort the collection by int . I've tried the following but it doesn't sorted the collection:

new ObservableCollection<KeyValuePair<int, string>>(
                 TestList .Where(p => p.Key > 0)
                 .GroupBy(p => p.Key)
                 .Select(grp => grp.First())
                 .OrderBy(p => p.Key)
                 );

How can I sort the collection? And will the Binding still works?

EDIT (doesn't work too):

public ObservableCollection<KeyValuePair<int, String>> TestList
{
    get { return testList; }
    set {
        testList = value;
        NotifyPropertyChanged("TestList");
    }
}

public void Test(int index)
{
    TestList.RemoveAt(index);
    TestList = new ObservableCollection<KeyValuePair<int, string>>(TestList.OrderBy(p => p.Key));
}

and GUI:

<TextBox Grid.Column="0" IsReadOnly="True"
Text="{Binding Path=Value , Mode=OneWay}" />

Answer 1

You don't have to make a group by. You just need a simple order by.

TestList.OrderBy(p => p.Key)

Answer 2

Since your source contains KeyValuePair objects, you might assume that the keys are already deduplicated. Hence, grouping has no use. Just keep the OrderBy and possibly your Where and you should be fine.

new ObservableCollection<KeyValuePair<int, string>>(
             TestList.Where(p => p.Key > 0)
             .OrderBy(p => p.Key)
             );