Windows UWP ScrollViewer scrollbar overlaps contents - xaml

How do you stop a ScrollViewer's scrollbar from overlapping content like this?
I have a RichTextBlock containing text and no matter how wide I make the RichTextBlock, or how I change the Margin and Padding values, I cannot get the scrollbar to move further to the right to stop this overlap from happening. I'm running Windows 10 and it is configured to hide scrollbars until the mouse pointer hovers over them.
Below is the XAML for my app.
<Page
x:Class="PaulWinPOS1.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:PaulWinPOS1"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<Grid Margin="0,26,0,0">
<Button x:Name="butConnect" Content="Connect" Margin="0,38,48,0" VerticalAlignment="Top" RenderTransformOrigin="-3.274,0.344" HorizontalAlignment="Right" Height="32" Click="ButConnect_Click" Width="92"/>
<Button x:Name="butLogin" Content="Login" Margin="0,92,48,0" VerticalAlignment="Top" RenderTransformOrigin="-3.274,0.344" HorizontalAlignment="Right" Height="32" Width="92" IsEnabled="False" Click="ButLogin_Click"/>
<Button x:Name="butAdd" Content="Add Item" Margin="0,143,48,0" VerticalAlignment="Top" RenderTransformOrigin="-3.274,0.344" HorizontalAlignment="Right" Width="92" IsEnabled="False" Click="ButAdd_Click"/>
<ScrollViewer x:Name="scrollViewerWeb"
HorizontalScrollBarVisibility="Auto"
VerticalScrollBarVisibility="Auto"
HorizontalAlignment="Left"
Width="350"
Padding="16,0"
Grid.RowSpan="10"
FontFamily="Segoe UI" RequestedTheme="Dark" ZoomMode="Enabled"
Margin="669,304,0,0" >
<WebView x:Name="webviewReceipt"
Margin="10,10,50,10"
HorizontalAlignment="Left"
Height="333" Width="300"
VerticalAlignment="Top"
ScrollViewer.VerticalScrollMode="Enabled"
ScrollViewer.VerticalScrollBarVisibility="Visible" />
</ScrollViewer>
<Button x:Name="butDisconnect" Content="Disconnect" Margin="0,244,48,0" VerticalAlignment="Top" RenderTransformOrigin="-3.274,0.344" HorizontalAlignment="Right" Height="32" Width="92" Click="ButDisconnect_Click"/>
</Grid>
</Page>

The scroll bar of WebView is special and cannot be solved by the conventional ScrollViewer additional properties, but the scroll bar of the WebView can be disabled through the CSS of the web page.
body {
-ms-overflow-style: none;
}
If you cannot modify the source code of the webpage, you can perform the following operations after the WebView content is loaded:
private async void webviewReceipt_DOMContentLoaded(WebView sender, WebViewDOMContentLoadedEventArgs args)
{
string js = "var style = document.createElement('style');" +
"style.type = 'text/css';" +
"style.innerHTML = \"body{ -ms-overflow-style: none !important; }\";" +
"document.getElementsByTagName('Head').item(0).appendChild(style); ";
await webviewReceipt.InvokeScriptAsync("eval", new string[] { js });
}
Update
If we need to display a scroll bar, we can add a padding-right to the body so that the scroll bar does not block the content.
private async void webviewReceipt_DOMContentLoaded(WebView sender, WebViewDOMContentLoadedEventArgs args)
{
string js = "var style = document.createElement('style');" +
"style.type = 'text/css';" +
"style.innerHTML = \"body{ padding-right: 24px; }\";" +
"document.getElementsByTagName('Head').item(0).appendChild(style); ";
await webviewReceipt.InvokeScriptAsync("eval", new string[] { js });
}

You need to add a Padding to ScrollViewer.
<ScrollViewer Padding="18, 0">
<RichTextBlock />
</ScrollViewer>
Usually the ScrollBar Width is 18.

It looks like you have the scroll bars enabled on both the web view and scroll viewer. You can try disabling the scroll bars on one of them to see if it makes a difference.

Related

Issues with child page's display when using Frames

Problem
This is the layout of my main pane:
<Page
x:Class="Communities.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:Communities"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d" Loaded="Page_Loaded" DataContext="{Binding RelativeSource={RelativeSource Mode=Self}}">
<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<Grid.RowDefinitions>
<RowDefinition Height="48" />
<RowDefinition Height="*" />
<RowDefinition Height="auto" />
</Grid.RowDefinitions>
...
<SplitView Grid.Row="1" Name="hamburgerMenu" OpenPaneLength="200" PaneBackground="#F02A2A2A">
<SplitView.Pane>
<ListView ItemsSource="{Binding}" IsItemClickEnabled="True" ItemClick="HamburgerItemClick">
... </ListView>
</SplitView.Pane>
<Frame Name="frame" />
</SplitView>
<Grid Grid.RowSpan="3" Name="popupArea" />
</Grid>
</Page>
the frame is where I load all my pages, so that the layout is always consistant.
Now, in most of my child pages I have defined AppBar control and attached it to the BottomAppBar property of that child page:
PostView.xaml
...
<Page.BottomAppBar>
<CommandBar>
<AppBarButton Label="Back" Icon="Back" Click="TryGoBack" />
<AppBarButton Label="Refresh" Icon="Refresh" Click="TryRefreshComments" />
<AppBarButton Label="Go to Community" Icon="Go" Click="TryOpenCommunity" />
</CommandBar>
</Page.BottomAppBar>
...
Here's where the trouble starts. It works fine on PC, as the layout is mostly static on desktop. There are no software keyboards required most of the time etc. On mobile it's more problematic: Screenshots
My thoughts
It seems like the frame that is used to display the child page is causing all sorts of problems. When the AppBar is defined in the main page it positions correctly.
I'd like to avoid the keyboard covering the textbox as well as the AppBar but I don't want to get rid of the frame control. I'd also prefer it if the page got "squished" when the keyboard shows up, instead of getting pushed upwards, but I'm not sure how to display the keyboard on the frame level, instead of the entire MainPage, default level.
What would be the best way to solve this situation?
Cheers!
As you know, if we set the Page.BottomAppBar in the root of the Page, there is no issue with Touch keyboard. It seems it is the best way to add the Page.BottomAppBar.
If you want to add the Page.BottomAppBar in the other page in the Frame, you should be able to customize your UI. The UWP provides similar behavior on the appearance of the touch keyboard by handling the Showing and Hiding events exposed by the InputPane object.
We can use the InputPaneVisibilityEventArgs.OccludedRect to get the region of the application's window that the input pane is covering.
For example:
public PostView()
{
this.InitializeComponent();
InputPane.GetForCurrentView().Showing += PostView_Showing;
InputPane.GetForCurrentView().Hiding += PostView_Hiding;
}
private void PostView_Hiding(InputPane sender, InputPaneVisibilityEventArgs args)
{
MyTextBox.Margin = new Thickness(0, args.OccludedRect.Height, 0, 0);
}
private void PostView_Showing(InputPane sender, InputPaneVisibilityEventArgs args)
{
MyTextBox.Margin = new Thickness(0, 0, 0, args.OccludedRect.Height);
}

Trying to implement color picker in uwp

I'm trying to implement color picker in uwp using below link
[1]: http://www.c-sharpcorner.com/article/coding4fun-colorpicker-control-in-uwp-with-xaml-and-c-sharp/
but while following process and implementing colorchange event it is giving error "unable to add event handler".Any idea would be appreciated
XAML
xmlns:my="using:Coding4Fun.Toolkit.Controls"
<my:ColorPicker x:Name="W_Paints"
Margin="216,203,-6,0" Height="40"
Width="40" VerticalAlignment="Top"
HorizontalAlignment="Left"/>
I tried to create a color picker with Coding4Fun package by following the above link and the color picker is successfully created with no error on my side.
I used version 2.1.8, and also test version 2.1.7 which also worked. My uwp app target version is build 14393, but I also test with target version 10240. So if you created a uwp app with "Coding4Fun Toolkit - Controls" 2.1.7 or 2.1.8 should be able work well. Here is the demo completing code.
XAML Code
<Page
x:Class="Coding4fun.MainPage"
...
xmlns:my="using:Coding4Fun.Toolkit.Controls" >
<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<TextBlock x:Name="tblTitle" HorizontalAlignment="Left" Margin="419,42,0,0" TextWrapping="Wrap" Text="Code4Fun ColorPicker control Demo" VerticalAlignment="Top" Height="37" Width="427" FontSize="24" FontWeight="Bold" />
<Button x:Name="btnCPopen" Content="Open Color Picker" HorizontalAlignment="Left" Margin="110,113,0,0" VerticalAlignment="Top" RenderTransformOrigin="-5.01,1.529" ToolTipService.ToolTip="Open color Picker for changing Background" Click="btnCPopen_Click" />
<Border x:Name="BorCP" BorderBrush="Black" BorderThickness="1" HorizontalAlignment="Left" Height="378" Margin="838,113,0,0" VerticalAlignment="Top" Width="354" />
<my:ColorPicker x:Name="CPtest" HorizontalAlignment="Left" Height="358" Margin="284,113,0,0" VerticalAlignment="Top" Width="374" ColorChanged="CPtest_ColorChanged" Visibility="Collapsed" />
</Grid>
Code behind
private void btnCPopen_Click(object sender, RoutedEventArgs e)
{
CPtest.Visibility = Visibility;
}
private void CPtest_ColorChanged(object sender, Windows.UI.Color color)
{
BorCP.Background = new SolidColorBrush(color);
}
I also upload the demo here you can download for testing and compare what's wrong with your project.

Binding shared flyout to 2 controls in Listview's DataTemplate in UWP Windows 10

I've got a shared Flyout defined in my <Page.Resources> as follows:
<Flyout x:Name="InfoFlyout" Opened="{Binding IsOpen,
ElementName=MyListView, Mode=TwoWay}">
<Grid>
<Button Foreground="White" Margin="5">
<StackPanel Orientation="Horizontal">
<TextBlock Text="Help"/>
</StackPanel>
</Button>
</Grid>
</Flyout>
But I get An object reference not set error when compiling, so I used the code from this article (Using Windows 8.1 Flyout control with MVVM) instead.
This seems to circumvent the problem I was having with the above code. Now my shared Flyout code looks like this:
<Flyout x:Name="InfoFlyout"
helpers:FlyoutHelpers.Parent="{Binding ElementName=MyListView}"
helpers:FlyoutHelpers.IsOpen="{Binding IsOpen, Mode=TwoWay}">
<Grid>
<Button Foreground="White" Margin="5">
<StackPanel Orientation="Horizontal">
<TextBlock Text="Help"/>
</StackPanel>
</Button>
</Grid>
</Flyout>
My ListView control (i.e. x:Name="MyListView") is binded to the page's ViewModel i.e. MainPageViewModel. The IsOpen property is defined in the MainViewModel.
Now in my ListView DataTemplate, I want my Flyout to open when I press and hold the ListViewItem or when pressing a button within the ListViewItem:
<DataTemplate>
<Grid FlyoutBase.AttachedFlyout="{StaticResource InfoFlyout}">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Image Grid.Column="0" Source={Binding MyImage} />
<Grid Grid.Column="1" Margin="5">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="Auto" />
</Grid.ColumnDefinitions>
<Button Width="30" Height="30"
Flyout="{StaticResource InfoFlyout}"
content="i">
</Button>
</Grid>
<interactivity:Interaction.Behaviors>
<core:EventTriggerBehavior EventName="Holding">
<actions:OpenFlyoutAction />
</core:EventTriggerBehavior>
</interactivity:Interaction.Behaviors>
</Grid>
</DataTemplate>
As you can see, I've got the Flyout "attached" to the Grid via:
FlyoutBase.AttachedFlyout="{StaticResource InfoFlyout}"
and I've got the same Flyout attached to the button within the ListViewItem itself via:
Flyout="{StaticResource InfoFlyout}"
I've put breakpoints on both my setter and getter for the IsOpen property and when page gets loaded, it does go into the getter but whenever I open or close my Flyout either via Holding or by pressing the 'i' button, it doesn't trigger the method below and therefore it doesn't change the IsOpen property.
private static void OnIsOpenPropertyChanged(DependencyObject d,
DependencyPropertyChangedEventArgs e) as defined in the FlyoutHelper class.
The reason I've set my ElementName to MyListView is that I want all my ListViewItem to be binded to the one property i.e. IsOpen as I need to detect whenever a flyout menu is opened irrelevant of which ListViewItem it belongs to.
How can I achieve or resolve this?
UPDATE - 1
The problem of accessing the shared menu has been resolved by using the following:
<Flyout x:Name="InfoFlyout"
helpers:FlyoutHelpers.Parent="{Binding ElementName=MyListView}"
helpers:FlyoutHelpers.IsOpen="{Binding IsOpen, Mode=TwoWay}">
and setting the button to
<Button Width="30" Height="30"
Command="{Binding InformationCommand}"
CommandParameter="{Binding}"
Flyout="{StaticResource InfoFlyout}">
Which is fine and as #ElvisXia mentioned, you can comment out the code in the OnIsOpenPropertyChanged as the positioning is already determined by the button located inside my ListViewItem.
There is however one outstanding problem. A small one btw, but nice if it can be solved. The shared flyout which is attached to the grid itself in the DataTemplate i.e.
<DataTemplate>
<Grid FlyoutBase.AttachedFlyout="{StaticResource InfoFlyout}">
It is being positioning based on the ListViewItem which technically is correct as I'm calling a different piece of code for that one i.e.
<interactivity:Interaction.Behaviors>
<core:EventTriggerBehavior EventName="Holding">
<actions:OpenFlyoutAction />
</core:EventTriggerBehavior>
</interactivity:Interaction.Behaviors>
And the OpenFlyoutAction is defined as follows:
public class OpenFlyoutAction : DependencyObject, IAction
{
public object Execute(object sender, object parameter)
{
FrameworkElement senderElement = sender as FrameworkElement;
FlyoutBase flyoutBase = FlyoutBase.GetAttachedFlyout(senderElement);
flyoutBase.ShowAt(senderElement);
return null;
}
}
Can I somehow stop using the OpenFlyoutAction and use the same code as provided in the article to open my Flyout wherever the user is holding his/her finger on the relevant ListViewItem rather than on top or below the actual ListViewItem?
I understand it's a little bit side track from the original issue which was to share a Flyout by to controls but may as well finish it as it is somehow relevant to the issue.
Thanks.
Change the type of Parent from Button to ListView. To open flyout in particular X,Y position is not possible in WP. You can choose PopUp control instead. Here is a link which i got open the pop up in tapped position. You can use VisualTreeHelper to get PopUp control of tapped ListViewItem
By Using Windows 8.1 Flyout control with MVVM , the author use parent to control where the flyout shows up.
So the author have codes like below(FlyoutHelpers.cs):
private static void OnIsOpenPropertyChanged(DependencyObject d,
DependencyPropertyChangedEventArgs e)
{
var flyout = d as Flyout;
var parent = (ListView)d.GetValue(ParentProperty);
if (flyout != null && parent != null)
{
var newValue = (bool)e.NewValue;
if (newValue)
flyout.ShowAt(parent);
else
flyout.Hide();
}
}
He use flyout.ShowAt(parent) to let flyout show at parent element. But in your codes you have binded the flyout to the button using:
<Button Width="30" Height="30"
Flyout="{StaticResource InfoFlyout}" content="i">
</Button>
So it is not necessary to let it show at it's parent any more. To fix the problem, you can comment out the statements like below:
private static void OnIsOpenPropertyChanged(DependencyObject d,
DependencyPropertyChangedEventArgs e)
{
//var flyout = d as Flyout;
//var parent = (ListView)d.GetValue(ParentProperty);
//if (flyout != null && parent != null)
//{
// var newValue = (bool)e.NewValue;
// if (newValue)
// flyout.ShowAt(parent);
// else
// flyout.Hide();
//}
}
Then you will see the flyout shows at the right place.

Displaying a Progress Bar

I have an image control in my main page and the code is as follows:
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
<StackPanel HorizontalAlignment="Left" Height="597" VerticalAlignment="Top" Width="440">
<Image x:Name="hinh1" Height="488" Stretch="Fill"/>
<ProgressBar Name="loading" Height="10" IsIndeterminate="True" Visibility="Collapsed"/>
</StackPanel>
</Grid>
and in code behind i have this code :
Uri hinh = new Uri
("http://taigamejar.net/wp-content/uploads/2014/01/Hinh-Anh-Dep-5.jpg", UriKind.Absolute);
hinh1.Source = new BitmapImage(hinh);
While waiting for the image to load, I want to call progress bar run to inform the user that it is loading. Once the the image has loaded, the progress bar should disappear. How can I do this?
If I were you, I would prefer to use , not ProgressBar.
So, I'll give
protected override void OnNavigatedTo(NavigationEventArgs e)
{
loading.IsActive = true;
Uri hinh = new Uri
("http://taigamejar.net/wp-content/uploads/2014/01/Hinh-Anh-Dep-5.jpg", UriKind.Absolute);
hinh1.Source = new BitmapImage(hinh);
hinh1.ImageOpened+=hinh1_ImageOpened; //loadingbar will be disappear when this triggered
}
private void hinh1_ImageOpened(object sender, RoutedEventArgs e)
{
loading.IsActive = false; //this will disable the progressring.
}
And XAML:
<StackPanel HorizontalAlignment="Left" Height="597" VerticalAlignment="Top" Width="400">
<Image x:Name="hinh1" Height="488" Stretch="Fill" ImageOpened="hinh1_ImageOpened"/>
<ProgressRing Name="loading" Height="109" IsActive="True" />
</StackPanel>
If you don't have WP8.1 SDK yet, you can get ProgressRing here: http://www.onurtirpan.com/onur-tirpan/english/windows-phone-english/using-progressring-in-windows-phone/

Enabling ScrollViewer HorizontalSnapPoints with bindable collection

I'm trying to create a similar experience as in the ScrollViewerSample from the Windows 8 SDK samples to be able to snap to the items inside a ScrollViewer when scrolling left and right. The implementation from the sample (which works) is like this:
<ScrollViewer x:Name="scrollViewer" Width="480" Height="270"
HorizontalAlignment="Left" VerticalAlignment="Top"
VerticalScrollBarVisibility="Disabled" HorizontalScrollBarVisibility="Auto"
ZoomMode="Disabled" HorizontalSnapPointsType="Mandatory">
<StackPanel Orientation="Horizontal">
<Image Width="480" Height="270" AutomationProperties.Name="Image of a cliff" Source="images/cliff.jpg" Stretch="None" HorizontalAlignment="Left" VerticalAlignment="Top"/>
<Image Width="480" Height="270" AutomationProperties.Name="Image of Grapes" Source="images/grapes.jpg" Stretch="None" HorizontalAlignment="Left" VerticalAlignment="Top"/>
<Image Width="480" Height="270" AutomationProperties.Name="Image of Mount Rainier" Source="images/Rainier.jpg" Stretch="None" HorizontalAlignment="Left" VerticalAlignment="Top"/>
<Image Width="480" Height="270" AutomationProperties.Name="Image of a sunset" Source="images/sunset.jpg" Stretch="None" HorizontalAlignment="Left" VerticalAlignment="Top"/>
<Image Width="480" Height="270" AutomationProperties.Name="Image of a valley" Source="images/valley.jpg" Stretch="None" HorizontalAlignment="Left" VerticalAlignment="Top"/>
</StackPanel>
</ScrollViewer>
The only difference with my desired implementation is that I don't want a StackPanel with items inside, but something I can bind to. I am trying to accomplish this with an ItemsControl, but for some reason the Snap behavior does not kick in:
<ScrollViewer x:Name="scrollViewer" Width="480" Height="270"
HorizontalAlignment="Left" VerticalAlignment="Top"
VerticalScrollBarVisibility="Disabled" HorizontalScrollBarVisibility="Auto"
ZoomMode="Disabled" HorizontalSnapPointsType="Mandatory">
<ItemsControl>
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal" />
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<Image Width="480" Height="270" AutomationProperties.Name="Image of a cliff" Source="images/cliff.jpg" Stretch="None" HorizontalAlignment="Left" VerticalAlignment="Top"/>
<Image Width="480" Height="270" AutomationProperties.Name="Image of Grapes" Source="images/grapes.jpg" Stretch="None" HorizontalAlignment="Left" VerticalAlignment="Top"/>
<Image Width="480" Height="270" AutomationProperties.Name="Image of Mount Rainier" Source="images/Rainier.jpg" Stretch="None" HorizontalAlignment="Left" VerticalAlignment="Top"/>
<Image Width="480" Height="270" AutomationProperties.Name="Image of a sunset" Source="images/sunset.jpg" Stretch="None" HorizontalAlignment="Left" VerticalAlignment="Top"/>
<Image Width="480" Height="270" AutomationProperties.Name="Image of a valley" Source="images/valley.jpg" Stretch="None" HorizontalAlignment="Left" VerticalAlignment="Top"/>
</ItemsControl>
</ScrollViewer>
Suggestions would be greatly appreciated!
Thanks to Denis, I ended up using the following Style on the ItemsControl and removed the ScrollViewer and inline ItemsPanelTemplate altogether:
<Style x:Key="ItemsControlStyle" TargetType="ItemsControl">
<Setter Property="ItemsPanel">
<Setter.Value>
<ItemsPanelTemplate>
<VirtualizingStackPanel Orientation="Horizontal"/>
</ItemsPanelTemplate>
</Setter.Value>
</Setter>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ItemsControl">
<ScrollViewer Style="{StaticResource HorizontalScrollViewerStyle}" HorizontalSnapPointsType="Mandatory">
<ItemsPresenter />
</ScrollViewer>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
Getting snap points to work for bound collections can be tricky. For snap points to work immediate child of ScrollViewer should implement IScrollSnapPointsInfo interface. ItemsControl doesn't implement IScrollSnapPointsInfo and consequently you wouldn't see snapping behaviour.
To work around this issue you got couple options:
Create custom class derived from ItemsControl and implement IScrollSnapPointsInfo interface.
Create custom style for items control and set HorizontalSnapPointsType property on ScrollViewer inside the style.
I've implemented former approach and can confirm that it works, but in your case custom style could be a better choice.
Ok, here is the simplest (and standalone) example for horizontal ListView with binded items and correctly working snapping (see comments in following code).
xaml:
<ListView x:Name="YourListView"
ItemsSource="{x:Bind Path=Items}"
Loaded="YourListView_OnLoaded">
<!--Set items panel to horizontal-->
<ListView.ItemsPanel>
<ItemsPanelTemplate>
<ItemsStackPanel Orientation="Horizontal" />
</ItemsPanelTemplate>
</ListView.ItemsPanel>
<!--Some item template-->
<ListView.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding}"/>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
background code:
private void YourListView_OnLoaded(object sender, RoutedEventArgs e)
{
//get ListView
var yourList = sender as ListView;
//*** yourList style-based changes ***
//see Style here https://msdn.microsoft.com/en-us/library/windows/apps/mt299137.aspx
//** Change orientation of scrollviewer (name in the Style "ScrollViewer") **
//1. get scrollviewer (child element of yourList)
var sv = GetFirstChildDependencyObjectOfType<ScrollViewer>(yourList);
//2. enable ScrollViewer horizontal scrolling
sv.HorizontalScrollMode =ScrollMode.Auto;
sv.HorizontalScrollBarVisibility = ScrollBarVisibility.Auto;
sv.IsHorizontalRailEnabled = true;
//3. disable ScrollViewer vertical scrolling
sv.VerticalScrollMode = ScrollMode.Disabled;
sv.VerticalScrollBarVisibility = ScrollBarVisibility.Disabled;
sv.IsVerticalRailEnabled = false;
// //no we have horizontally scrolling ListView
//** Enable snapping **
sv.HorizontalSnapPointsType = SnapPointsType.MandatorySingle; //or you can use SnapPointsType.Mandatory
sv.HorizontalSnapPointsAlignment = SnapPointsAlignment.Near; //example works only for Near case, for other there should be some changes
// //no we have horizontally scrolling ListView with snapping and "scroll last item into view" bug (about bug see here http://stackoverflow.com/questions/11084493/snapping-scrollviewer-in-windows-8-metro-in-wide-screens-not-snapping-to-the-las)
//** fix "scroll last item into view" bug **
//1. Get items presenter (child element of yourList)
var ip = GetFirstChildDependencyObjectOfType<ItemsPresenter>(yourList);
// or var ip = GetFirstChildDependencyObjectOfType<ItemsPresenter>(sv); //also will work here
//2. Subscribe to its SizeChanged event
ip.SizeChanged += ip_SizeChanged;
//3. see the continuation in: private void ip_SizeChanged(object sender, SizeChangedEventArgs e)
}
public static T GetFirstChildDependencyObjectOfType<T>(DependencyObject depObj) where T : DependencyObject
{
if (depObj is T) return depObj as T;
for (var i = 0; i < VisualTreeHelper.GetChildrenCount(depObj); i++)
{
var child = VisualTreeHelper.GetChild(depObj, i);
var result = GetFirstChildDependencyObjectOfType<T>(child);
if (result != null) return result;
}
return null;
}
private void ip_SizeChanged(object sender, SizeChangedEventArgs e)
{
//3.0 if rev size is same as new - do nothing
//here should be one more condition added by && but it is a little bit complicated and rare, so it is omitted.
//The condition is: yourList.Items.Last() must be equal to (yourList.Items.Last() used on previous call of ip_SizeChanged)
if (e.PreviousSize.Equals(e.NewSize)) return;
//3.1 get sender as our ItemsPresenter
var ip = sender as ItemsPresenter;
//3.2 get the ItemsPresenter parent to get "viewable" width of ItemsPresenter that is ActualWidth of the Scrollviewer (it is scrollviewer actually, but we need just its ActualWidth so - as FrameworkElement is used)
var sv = ip.Parent as FrameworkElement;
//3.3 get parent ListView to be able to get elements Containers
var yourList = GetParent<ListView>(ip);
//3.4 get last item ActualWidth
var lastItem = yourList.Items.Last();
var lastItemContainerObject = yourList.ContainerFromItem(lastItem);
var lastItemContainer = lastItemContainerObject as FrameworkElement;
if (lastItemContainer == null)
{
//NO lastItemContainer YET, wait for next call
return;
}
var lastItemWidth = lastItemContainer.ActualWidth;
//3.5 get margin fix value
var rightMarginFixValue = sv.ActualWidth - lastItemWidth;
//3.6. fix "scroll last item into view" bug
ip.Margin = new Thickness(ip.Margin.Left,
ip.Margin.Top,
ip.Margin.Right + rightMarginFixValue, //APPLY FIX
ip.Margin.Bottom);
}
public static T GetParent<T>(DependencyObject reference) where T : class
{
var depObj = VisualTreeHelper.GetParent(reference);
if (depObj == null) return (T)null;
while (true)
{
var depClass = depObj as T;
if (depClass != null) return depClass;
depObj = VisualTreeHelper.GetParent(depObj);
if (depObj == null) return (T)null;
}
}
About this example.
Most of checks and errors handling is omitted.
If you override ListView Style/Template, VisualTree search parts must be changed accordingly
I'd rather create inherited from ListView control with this logic, than use provided example as-is in real code.
Same code works for Vertical case (or both) with small changes.
Mentioned snapping bug - ScrollViewer bug of handling SnapPointsType.MandatorySingle and SnapPointsType.Mandatory cases. It appears for items with not-fixed sizes
.