Scrollviewer in Metro app - scroll by touch and handle other gesture - windows-8

I have page with Grid and Scrollviewer:
<Grid x:name="mainGrid">
...
<ScrollViewer Name="mainScroller" ScrollViewer.HorizontalScrollBarVisibility="Visible" ScrollViewer.HorizontalScrollMode="Enabled">
...
</ScrollViewer>
...
</Grid>
I want make gesture handling for vertical touch move (move up with finger), but I want preserve scrolling mainScroller content by horizontal touch move too.
I tried add for mainGrid ManipulationCompleted="Grid_ManipulationCompleted":
private void Grid_ManipulationCompleted(object sender, ManipulationCompletedRoutedEventArgs e)
{
if (e.Cumulative.Translation.Y < -50 && e.Velocities.Linear.Y<1000)
{
...make some action...
}
}
Final effect is that, if I use ManipulationMode="TranslateY" for mainGrid, then vertical touch move works, but horizontal scrolling not, and when I not use it, horizontal scrolling works, but vertical touch move not. Is it possible to make both this features functional?
Sorry for my English.

It might help to understand your scenario, but in general you should not create new gestures that could potentially conflict with built-in gestures, like you are proposing.
John Wiese
Microsoft - Sr. Technical Evangelist
jwiese#microsoft.com
#johnwiese

Related

Xamarin TapGestureRecognizer sometime does not work properly

I am currently building my mobile application using Xamarin.Forms and i encountered a problem (on both platform of ios and android) when i tried to use Xamarin.Forms gestures more particularly a tap gesture on a xaml Label. Because i want to use this label as a link.
The problem is that this tab gesture that i used does not work sometime ( approximately 5 times test = 1 time bug).
During DEBUG when the problem occured i see that the tabbing is still recognized but it did not respond in the action i set up.
It occurs on both iOS and Android devices.
Here is my XAML code:
<RelativeLayout>
<Image Source="icon_question" WidthRequest="15" HeightRequest="15"></Image>
<Label Margin="15, -3, 0, 0" HorizontalOptions="CenterAndExpand" HorizontalTextAlignment="Center"
Text="Some text" TextColor="Blue" FontSize="15" TextDecorations="Underline">
<Label.GestureRecognizers>
<TapGestureRecognizer Tapped="_tabLinkForgetPassword"></TapGestureRecognizer>
</Label.GestureRecognizers>
</Label>
</RelativeLayout>
and here is my code behind:
private void _tabLinkForgetPassword(object s, EventArgs e)
{
App.Current.MainPage = new ResetPasswordPage(false);
}
I expect that the tab respond everytime, not just sometime like this. I appreciate all your help.
As stated by AndroDevil, you have to handle the tap gesture on a parent (a Grid, StackLayout, ContentView, whatever you want). in your case, why don't you use the Relative layout ? Thus, you can tap either the Label or the Image.
When you think it doesn't work, it is just that when you tap on the empty space : between characters (or even inside the void of a char like O (but admit it, kind of hard to tap on those few pixels)) of your text.
Last, you don't need to set NumberOfTapsRequired because as far as I remember, it is the default value.

How to switching between InkCanvas and Canvas in UWP

I'm struggling with new UWP InkCanvas for my apps.If you are familiar with the new InkCanvas in UWP, I would truly appreciate your help.
I have a UWP apps need to switching between InkCanvas and Canvas, which I wish to use InkCanvas for Drawing, Canvas for creating Contents such as RichEditbox, Image, etc...
My XAML is below
<Grid Margin="100,0,100,0" Background="White" x:Name="MainGrid" PointerMoved="MyCanvas_PointerMoved" PointerReleased="MyCanvas_PointerReleased" PointerPressed="MyCanvas_PointerPressed">
<Canvas x:Name="MyCanvas" />
<InkCanvas x:Name="inkCanvas" Canvas.ZIndex="0" />
<!-- End "Step 2: Use InkCanvas to support basic inking" -->
</Grid>
I tried to make my Canvas ZIndex greater than InkCanvas by using
private void AppBarButton_Click(object sender, RoutedEventArgs e)
{
if(Canvas.GetZIndex(MyCanvas) > 1)
{
Canvas.SetZIndex(MyCanvas, 0);
}
else
{
Canvas.SetZIndex(MyCanvas, 5);
}
}
However I can't make my Canvas come to the front, the InkCanvas keep Capturing my stroke if I Draw on it instead.
Does anyone know how to switch the Canvas and InkCanvas in my Grid without changing the Visibility of my InkCanvas to Collapsed?
By default the Canvas background is empty (null), so it will not capture pointer input and will pass it through to the InkCanvas.
If you want to prevent this, you could set its Background to Transparent.
However, when you start putting some controls on the Canvas itself, they should capture the pen input and not let it through to the InkCanvas.

Start An Event After Scrolling

I'm new to Windows Phone apps development, and I've created a scrolling menu using the following xaml code :
<ScrollViewer HorizontalAlignment="Left" Margin="18,0,0,0" Name="scrollViewer1" VerticalAlignment="Top" Width="450" HorizontalScrollBarVisibility="Auto" Grid.Row="1">
<StackPanel Height="Auto" Name="stackPanel1" Width="Auto">
<Button Height="620" FontSize="120" Name="gotoGmail" Width="Auto">Gmail</Button>
<Button Height="620" FontSize="120" Name="gotoYahoo" Width="Auto">Yahoo</Button>
</StackPanel>
</ScrollViewer>
I'd like to know whether it's possible to start an event once the user scrolls the menu from one button to another. If it is possible, i'd be grateful if you could explain how. If it's not , i'd like to hear about how could I do it using different tools rather than ScrollViewer. Thanks in advance !
There's no "Scrolled" event on the ScrollViewer, but what you can do is two-way bind a property to VerticalOffset. That lets you trigger an event/command from your view/viewmodel when the scroll changes.
Something like this:
<ScrollViewer VerticalOffset="{Binding VerticalOffset,Mode=TwoWay}" ...
And then in the data context:
public double VerticalOffset
{
get { return _verticalOffset; }
set
{
_verticalOffset = value;
// call "on scroll changed" actions here
}
}
private double _verticalOffset = 0;
how could I do it using different tools rather than ScrollViewer
You can of course make a scrolling menu using other approaches. I'll bet there is some nifty approach you could figure, using the WinRT transitions/animations stuff, but I'm not familiar enough with those to say. Here are some others (not sure which would be best/easiest for your scenario):
Probably using Canvas would be a quick-and-dirty way to do it (just set up buttons that set off Canvas.Left and Canvas.Top animations).
Extending ItemsControl along with a custom ControlTemplate would be a good approach if you want to create a re-usable component.
I like extending Panel, but you have to do the animations manually using a DispatcherTimer, and you have to lay out the buttons yourself using Measure and Arrange.

Zooming in and out in Grid, Images on WinRT (Metro style app)

I'm trying to implement something in my app, I need to show an image, and let the user pinch in and out of the images.
I think its possible using the ScrollViewer, but I couldnt get it to work, help?
I hate to oversimplify this, but the WinRT XAML ScrollViewer has gesture manipulation built in.
You can see what I mean here. This might not be what you want. But it's sure a simple approach and might fit a certain % of scenarios. Maybe even yours.
Controls that incorporate a ScrollViewer in compositing often set a value for ZoomMode in the default template and starting visual states, and it is this templated value that you will typically start with. Controls with a ScrollViewer as part of their composition typically use template binding such that setting the attached property at the level of the control will change the scroll behavior of the ScrollViewer part within the control. Otherwise, it may be necessary to replace the template in order to change the scroll behavior of a ScrollViewer part.
Check out Morten Nielsen's article on Building A Multi-Touch Photo Viewer Control. It's for Silverlight/Windows Phone, but if you just enable manipulations on the image and change a few types in manipulation events - it should work great.
A simple solution that might be enough for you is to just put the image in a ScrollViewer, although to see it working - you need a touch screen or run it in a simulator (use the pinch tool, then drag and scroll on the image to zoom in/out).
You can also zoom it with code:
<Grid
Background="{StaticResource ApplicationPageBackgroundBrush}">
<ScrollViewer
x:Name="myScrollViewer">
<Image
Source="/Assets/SplashScreen.png" />
</ScrollViewer>
</Grid>
.
public BlankPage()
{
this.InitializeComponent();
myScrollViewer.ZoomMode = ZoomMode.Enabled; // default
Test();
}
private async void Test()
{
while (true)
{
for (double x = 0; x < 2 * Math.PI; x += Math.PI / 30)
{
await Task.Delay(1000 / 30);
float factor = (float)(1.0 + Math.Sin(x) / 10);
myScrollViewer.ZoomToFactor(factor);
}
}
}

How do you utilize the flipview and make a "selection" by tapping or clicking the screen?

In Win 8, the flipview control is a great control to browse the collection. But how or what is the best way to make a "selection" with a tap or a mouse click? I can always put a button outside of the flip view, but that's not the touch experience that everyone of a tablet would expect.
can someone give some example code (XAML/C#) of how to setup a flipview control with a selection of some sort that would navigate to a totally different page?
I wrote some sample code that works, if I'm understanding the question correctly. I am able to swipe through the FlipView and tap the individual item:
<FlipView Tapped="FlipView_Tapped_1">
<Image Source="Images/Apple.jpg" />
<Image Source="Images/Orange.jpg" />
<Image Source="Images/Banana.jpg" />
</FlipView>
And then
private YourTypeHere SelectedItem;
private void FlipView_Tapped_1(object sender, TappedRoutedEventArgs e)
{
this.SelectedItem = (sender as FlipView).SelectedItem;
}
You might not want to set a field, but you get the idea. Hopefully, you will be setting something in your view model. From there you can nav away or anything you need. A FlipView inherits from ItemsControl just like every other XAML repeater. So you can treat it exactly the same. http://msdn.microsoft.com/en-us/library/system.windows.controls.itemscontrol.aspx