Dutton's blog

AKA: "How to give a WPF ListView a sticky bottom" but I thought better of making that the blog post title =)

If you've ever tried to auto-scroll a WPF ListView when a new item is added, you will find that as you can't access the ListView's internal ScrollViewer from XAML this is a trickier task than it should be.

Here is an auto-scrolling ListView that will ensure that any new items added will be automatically scrolled into view. This behavior is overridden if the scrollbar position is not currently at the bottom.

public class AutoScrollingListView : ListView
{
  private ScrollViewer _scrollViewer;


      

If you have more than a handful of photos you want to delete on an iPhone or iPad it can be a bit of a pain to do manually and I often find on my 4S that if you have too many photos, deleting the entire Camera Roll through Settings -> General -> Usage just doesn't work. Here's how to do it with a Mac.

NB: This will permanently delete photos from your phone, make sure you've backed up or sync'd anything you want to keep before doing this.

1. Connect your phone via USB to your Mac.
2. Open the Preview application, the easiest way is to search for it using Spotlight (the magnifying glass top right).
   
3. Once open, from the File menu you should see your iOS device listed, mine's called "Richard's iPhone". Select Import from....
   
4. You'll then see thumbnails of all of the photos on your device. I clearly like coffee =).
   
5. Now select the photos you want to delete, either individually (holding down CMD to multi-select) or CMD-A to select all.
   
6. And hit the delete button at the bottom.
7. That's it.... it's as simple as that, you're photos will be deleted.

UPDATE 12/11/2013: Fixed a mistake in the example code; the setter and getter shouldn't have "Property" in the name.

I have a simple requirement to select all of the text in a WPF TextBox when it receives focus, this lets a user tab through a bunch of TextBoxes and edit the values directly without having to use the mouse.

Although there are a few methods I could use, I thought I'd tackle this using the "Ramora", or "Attached Behavior" pattern. I always forget the syntax, hence this post.

Implementing an Attached Behavior involves creating a boolean Attached Property to indicate whether the behavior is to be applied, and then implementing the behavior in the property's change handler, like this:

    public class TextBoxBehavior
    {
        public static bool GetSelectAllTextOnFocus(TextBox textBox)
        {
            return (bool)textBox.GetValue(SelectAllTextOnFocusProperty);
        }

        public static void SetSelectAllTextOnFocus(TextBox textBox, bool value)
        {
            textBox.SetValue(SelectAllTextOnFocusProperty, value);
        }

        public static readonly DependencyProperty SelectAllTextOnFocusProperty =
            DependencyProperty.RegisterAttached(
                "SelectAllTextOnFocus",
                typeof (bool),
                typeof (TextBoxBehavior),
                new UIPropertyMetadata(false, OnSelectAllTextOnFocusChanged));

        private static void OnSelectAllTextOnFocusChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            var textBox = d as TextBox;
            if (textBox == null) return;

            if (e.NewValue is bool == false) return;

            if ((bool) e.NewValue)
            {
                textBox.GotFocus += SelectAll;
                textBox.PreviewMouseDown += IgnoreMouseButton;
            }
            else
            {
                textBox.GotFocus -= SelectAll;
                textBox.PreviewMouseDown -= IgnoreMouseButton;
            }
        }

        private static void SelectAll(object sender, RoutedEventArgs e)
        {
            var textBox = e.OriginalSource as TextBox;
            if (textBox == null) return;
            textBox.SelectAll();
        }

        private static void IgnoreMouseButton(object sender, System.Windows.Input.MouseButtonEventArgs e)
        {
            var textBox = sender as TextBox;
            if (textBox == null || textBox.IsKeyboardFocusWithin) return;

            e.Handled = true;
            textBox.Focus();
        }
    }

Which means you can use it like this in XAML:

<TextBox Text="Some Text" behaviors:TextBoxBehavior.SelectAllTextOnFocus="True"/>

So as you can see, it's really quite simple. I hook into the GotFocus event in `OnSelectAllTextOnFocusChanged`, and call `SelectAll` where I select all of the TextBox's text.

I added a further event handler to ensure that mouse clicks within the TextBox didn't highlight the text when it already had focus but this isn't essential.

I am having a few problems with the latest version of AvalonDock (in particular my custom PRISM RegionAdapter implementation, blog post\moan to follow one day when I get a chance) so have had to roll back to the version I developed under which worked for me.

You can't do this via the "Manage nuget packages" dialog in Visual Studio as that only lets you install\uninstall\manage the latest version of packages, so you have to fire up the "Package Manager Console" (under View -> Other Windows, if you don't already have it open) and use the command line.

The command to list available versions is:

Get-Package -ListAvailable -Filter AvalonDock -AllVersions

And then you can use the following to install a specific version (make sure you have the project you want to install into selected in the "Default project" drop-down) :

Install-Package AvalonDock -Version 2.0.1320

And lo and behold, you have 2.0.1320 of AvalonDock installed and your RegionAdapter suddenly works again!