Basically, I'm trying to make the canvas listen for a touch input (tap) and will increment the number of taps on screen. It isn't working when I touch the screen on my device. I debugged my code and nothing seems out of the ordinary except that the touch is not detected. I checked ZIndex and the canvas is in front of the screen to be touchable. How do I make it work?
XAML:
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
<TextBlock Name="counter" FontSize="150" HorizontalAlignment="Center" TextWrapping="Wrap" Text="0" VerticalAlignment="Center" Margin="188,10,187,397"/>
<Button Content="Reset" HorizontalAlignment="Stretch" Margin="-18,535,-18,0" VerticalAlignment="Top" Click="Button_Click"/>
<Canvas ZIndex="0" Name="Canvas" HorizontalAlignment="Center" Height="535" VerticalAlignment="Top" Width="446" MouseLeftButtonDown="Canvas_MouseLeftButtonDown" MouseLeftButtonUp="Canvas_MouseLeftButtonUp" MouseLeave="Canvas_MouseLeave"/>
</Grid>
C#:
int taps = 0; // create var to detect number of times, user touches the screen
// Constructor
public MainPage()
{
InitializeComponent();
}
// method to register the touch as the finger is placed on the screen
private void Canvas_MouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
//Canvas c = sender as Canvas;
counter.Text = "TOUCHED!";
}
//method register the touch as the finger is lifting up from the screen
private void Canvas_MouseLeftButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
//Canvas c = sender as Canvas;
taps++;
counter.Text = taps.ToString(); //convert var from int to string
}
//method register the touch as the finger leaves the area of the screen
private void Canvas_MouseLeave(object sender, System.Windows.Input.MouseEventArgs e)
{
//Canvas c = sender as Canvas;
MessageBox.Show("You left the screen without lifting your finger. That does not count as a tap!", "Caution!", MessageBoxButton.OK);
}
// method to reset the counter to zero when button is pressed and released
private void Button_Click(object sender, RoutedEventArgs e)
{
taps = 0; // reset the count
counter.Text = taps.ToString(); // convert var from int to string
}
I don't know why you want to do it with Canvas - it won't work as you have nothing in this Canvas, so it can't register your click/tap, Canvas is also hard to adjust to screen. I think it can be done simpler way if you want to do it with MouseUp/Down - subscribe directly to Grid containing your elements instead of filling this Grid with additional Canvas:
In XAML:
<Grid x:Name="ContentPanel" Margin="12,0,12,0" Background="Transparent">
<Grid.RowDefinitions>
<RowDefinition Height="7*"/>
<RowDefinition Height="1*"/>
<RowDefinition Height="1*"/>
</Grid.RowDefinitions>
<TextBlock Name="counter" FontSize="150" HorizontalAlignment="Center" TextWrapping="Wrap" Text="0" VerticalAlignment="Center" Grid.Row="0"/>
<Button Content="Reset" HorizontalAlignment="Stretch" VerticalAlignment="Center" Click="Button_Click" Grid.Row="1"/>
<TextBlock Name="Touched" FontSize="50" HorizontalAlignment="Center" TextWrapping="Wrap" Text="Touched" VerticalAlignment="Center" Visibility="Collapsed" Grid.Row="2"/>
</Grid>
In code behind:
private int taps = 0;
public MainPage()
{
InitializeComponent();
ContentPanel.MouseLeftButtonDown += ContentPanel_MouseLeftButtonDown;
ContentPanel.MouseLeftButtonUp += ContentPanel_MouseLeftButtonUp;
}
private void ContentPanel_MouseLeftButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
taps++;
counter.Text = taps.ToString(); //convert var from int to string
Touched.Visibility = Visibility.Collapsed;
}
private void ContentPanel_MouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
Touched.Visibility = Visibility.Visible;
}
// method to reset the counter to zero when button is pressed and released
private void Button_Click(object sender, RoutedEventArgs e)
{
taps = 0; // reset the count
counter.Text = taps.ToString(); // convert var from int to string
}
As you can see I've subscribed to Grid events (which covers whole screen) - but to make it work I had to set its Background Brush to Transparent, otherwise it will work only if you touch text.
There are many other ways to make your App work, but I hope this will help.
Is there a reason why you don't use the touch-events?
Instead of using MouseLeftButtonDown and MouseLeftButtonUp you should use TouchDown and TouchUp.
Only when you don't handle the touch events or the manipulation events they will be mapped to mouse events. In my experience with touch a single tap also not always gets mapped to MouseLeftButtonDown. As far as I know you could also with mouse events only recoginse one finger. When you want to count more fingers it's necessary to use the TouchDown/TouchUp events.
The problem lies in the overlapping style of the grid
so either make grid rows or define a stackpanel inside the grid, something like this.
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
<stackpanel>
<TextBlock Name="counter" FontSize="150" HorizontalAlignment="Center" TextWrapping="Wrap" Text="0" Margin="0,0,0,0"/>
<Canvas ZIndex="0" Name="Canvas" HorizontalAlignment="Center" Height="535" VerticalAlignment="Top" Width="446" MouseLeftButtonDown="Canvas_MouseLeftButtonDown" MouseLeftButtonUp="Canvas_MouseLeftButtonUp" MouseLeave="Canvas_MouseLeave"/>
<Button Content="Reset" HorizontalAlignment="Stretch" Margin="0,0,0,0" VerticalAlignment="Top" Click="Button_Click"/>
</stackpanel>
</Grid>
Try and check now.
You should set your Background property. If you don't want any background set it to Transparent:
<Canvas ZIndex="99" Background="Transparent" Name="Canvas" HorizontalAlignment="Center" Height="535" VerticalAlignment="Top" Width="446" Tapped="Canvas_CountMyTaps"/>
(If you want the canvas to be on Top be sure to make it have a greater ZIndex than the other elements that it overlaps)
If not set (the default value is null) the element won't capture any taps/click etc, it will be as if they "fall through".
Also, consider using the Tapped event which is a "higher level" event that will respond to clicks, taps with the finger, stylus, etc.
Related
I can't get why my canvas doesn't get pointer events. Below my code and a part of the XAML layout:
XAML
<Canvas
x:Name="cPad"
Canvas.ZIndex="99"
Grid.Column="0"
PointerPressed="Pad_PointerPressed">
<Rectangle
x:Name="rPicker"
Width="24"
Height="24"
Stroke="Black"
Fill="White"
StrokeThickness="3"/>
</Canvas>
C#
private void Pad_PointerPressed(object sender, PointerRoutedEventArgs e)
{
cPad.CapturePointer(e.Pointer);
var point = e.GetCurrentPoint(cPad).Position;
Canvas.SetLeft(rPicker, point.X);
Canvas.SetTop(rPicker, point.Y);
e.Handled = true;
}
The problem that rPicker moves only if I click on rPicker... But I need to Pad_PointerPressed executes for any point on canvas. How can I make it?
Set Canvas.Background property to Transparent to enable PointerPressed events:
<Canvas
...
Background="Transparent"
>
...
</Canvas>
I have the following XAML code, which creates two stack panels within a big parent Stack Panel. I would like to be able to drag each small stack panel within the parent bigStack panel.
XAML
<StackPanel BorderThickness="1" BorderBrush="Black" x:Name="bigStack">
<StackPanel x:Name="smallStack1" ManipulationMode="All" ManipulationDelta="objectManipulationDelta" ManipulationStarting="objectManipulationStarting">
<TextBlock Text="John Doe"/>
<TextBlock Text="CEO"/>
</StackPanel>
<StackPanel x:Name="smallStack2" ManipulationMode="All" ManipulationDelta="objectManipulationDelta" ManipulationStarting="objectManipulationStarting">
<TextBlock Text="Jane Doe"/>
<TextBlock Text="CTO"/>
</StackPanel>
</StackPanel>
C# backend:
private TranslateTransform dragtranslation ;
private void objectManipulationDelta(object sender, ManipulationDeltaRoutedEventArgs e)
{
dragtranslation.X += e.Delta.Translation.X;
dragtranslation.Y += e.Delta.Translation.Y;
}
private void objectManipulationStarting(object sender, ManipulationStartingRoutedEventArgs e)
{
var stackDragged = e.OriginalSource as StackPanel;
dragtranslation = new TranslateTransform();
stackDragged.RenderTransform = this.dragtranslation ;
}
Original Code found here (Official Microsoft UWP Documentation) but adapted (obviously wrongly) to suit my needs
PROBLEM 1
1) Drag smallStack1 for the first time: OK
2) Drag smallStack2 for the second time: Reverts back to the original position
PROBLEM 2
1) Drag smallStack1 for the first time: OK
2) Drag smallStack2 for the first time: OK
3) Drag either of the smallStacks again: Reverts back to the original position
You can check the problems in the .gif below:
WHAT I WISH TO ACCOMPLISH
Drag the controls using a common method, because I plan to dynamically create more controls inside the bigStack panel.
You are basically reinstantiating TranslateTransform everytime you click on an Item. That is the reason why when you click on the item second time, it navigates back to 0,0 which is the original position for TranslateTransform.
To Handle this in a easier way, this is what I would do.
1) I would give explicit TranslateTransform to the smallStackPanel's
<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<StackPanel BorderThickness="1" BorderBrush="Black" x:Name="bigStack">
<StackPanel x:Name="smallStack1" ManipulationMode="All" ManipulationDelta="objectManipulationDelta" >
<StackPanel.RenderTransform>
<TranslateTransform />
</StackPanel.RenderTransform>
<TextBlock Text="John Doe"/>
<TextBlock Text="CEO"/>
</StackPanel>
<StackPanel x:Name="smallStack2" ManipulationMode="All" ManipulationDelta="objectManipulationDelta" >
<StackPanel.RenderTransform>
<TranslateTransform />
</StackPanel.RenderTransform>
<TextBlock Text="Jane Doe"/>
<TextBlock Text="CTO"/>
</StackPanel>
</StackPanel>
</Grid>
And then all i need to do in codebehind is handle ManipulationDelta.
private void objectManipulationDelta(object sender, ManipulationDeltaRoutedEventArgs e)
{
var stackDragged = e.OriginalSource as StackPanel;
(stackDragged.RenderTransform as TranslateTransform).X += e.Delta.Translation.X;
(stackDragged.RenderTransform as TranslateTransform).Y += e.Delta.Translation.Y;
}
Output:
Update
To add TranslateTransform from Code
StackPanel sp = new StackPanel();
sp.RenderTransform = new TranslateTransform();
Good Luck.
I'm using PointerEntered and PointerExited on my grid to change it's color when pointer is inside, and sometimes (most of time) PointerExited does not trigger on my w10m phone, I used break point to check that. Same with Poiner(Canceled/CaptureLost). It doesn't trigger even if I touch outside the grid, when pointer is 100% outside.
Any ideas how to fix that?
My code (if needed):
private void ButtonPointerEntered(object sender, PointerRoutedEventArgs e)
{
var c = (ButtonGrid.Background as SolidColorBrush).Color;
ButtonGrid.Background = new SolidColorBrush(Color.FromArgb(60, c.R, c.G, c.B));
}
private void ButtonPointerExited(object sender, PointerRoutedEventArgs e) //Does not trigger
{
var c = (ButtonGrid.Background as SolidColorBrush).Color;
ButtonGrid.Background = new SolidColorBrush(Color.FromArgb(0, c.R, c.G, c.B));
}
XAML:
<Grid PointerEntered="ButtonPointerEntered" Tapped="ButtonTapped" x:Name="ButtonGrid" Background="{ThemeResource ApplicationForegroundThemeBrush}" PointerExited="ButtonPointerExited">
<Grid.RowDefinitions>
<RowDefinition Height="auto"/>
<RowDefinition/>
</Grid.RowDefinitions>
<TextBlock x:Name="IconTB" FontFamily="Segoe MDL2 Assets" FontSize="18" HorizontalAlignment="Center" VerticalAlignment="Top" Margin="0,3,0,0"/>
<TextBlock x:Name="TextTB" Grid.Row="1" FontSize="13" HorizontalAlignment="Center" TextWrapping="WrapWholeWords" TextAlignment="Center" Margin="0,0,0,2"/>
</Grid>
I started my app without debugging with visual studio and... It work 100% correct. So the problem was in debugging
I have an InkCanvas over the front of my application.
I want it to only interact with Stylus/Pen events. All other events should be passed through to the various controls underneath the canvas.
The intention is that I detect gestures on the InkCanvas with a pen, while other manipulation events are handled by the controls below the InkCanvas (such as touch and inertial manipulation).
Currently I've tried disabling manipulation events, capturing them, setting handled = false. So far I can't find the right solution. Any ideas?
You can detect the input mode (PointerDeviceType) in the Pointer events of the InkCanvas, for example:
<ScrollViewer x:Name="scrollViewer" Width="400" Height="400" Background="LightBlue" VerticalAlignment="Center" HorizontalAlignment="Center"
PointerPressed="scrollViewer_PointerPressed">
<StackPanel>
<Rectangle Height="300" Width="300" Fill="Red"/>
<Rectangle Height="300" Width="300" Fill="Black"/>
</StackPanel>
</ScrollViewer>
<InkCanvas x:Name="inkCanvas" Width="400" Height="400" GotFocus="inkCanvas_GotFocus" VerticalAlignment="Center" HorizontalAlignment="Center"
Tapped="inkCanvas_Tapped" PointerPressed="inkCanvas_PointerPressed"/>
code behind:
private void inkCanvas_PointerPressed(object sender, PointerRoutedEventArgs e)
{
// Accept input only from a pen or mouse with the left button pressed.
PointerDeviceType pointerDevType = e.Pointer.PointerDeviceType;
if (pointerDevType == PointerDeviceType.Pen)
{
//TODO:
}
else
{
// Process touch or mouse input
inkCanvas.Visibility = Visibility.Collapsed;
}
}
private void scrollViewer_PointerPressed(object sender, PointerRoutedEventArgs e)
{
PointerDeviceType pointerDevType = e.Pointer.PointerDeviceType;
if (pointerDevType == PointerDeviceType.Pen)
{
inkCanvas.Visibility = Visibility.Visible;
}
else
{
// Process touch or mouse input
inkCanvas.Visibility = Visibility.Collapsed;
}
}
I'm using a list of textboxes for a registering document in a WP8 app.
The number of textboxes is quite large, so the user has to scroll between them.
To navigate between one field to another, I added two applicationbarIcons, next and previous. Pressing on next will change the focus to the next textbox from list, and scroll the content of the scroll viewer with the height of the textbox (in this case 50).
However, sometimes, when switching the focus to the element bellow, the keyboard covers the text box. (the content doesn't scroll up).
Is there a way to force the textbox to move above the keyboard, even if it is in a scroll view?
<ScrollViewer x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
<StackPanel>
<TextBlock Text="{Binding Source={StaticResource LocalizedStrings}, Path=LocalizedResources.STRING_CONTACT}" Margin="10,5" FontWeight="SemiBold" Foreground="#878780"></TextBlock>
<StackPanel Margin="10,5" Height="190" Background="#F4F3F4">
<TextBox LostFocus="firstNameTxt_LostFocus_1" GotFocus="firstNameTxt_GotFocus_1" Margin="0,-7" FontSize="23" x:Name="firstNameTxt" BorderThickness="0" Background="Transparent" InputScope="PersonalFullName"><TextBox>
<TextBox LostFocus="firstNameTxt_LostFocus_1" GotFocus="firstNameTxt_GotFocus_1" Margin="0,-7" FontSize="23" x:Name="lastNameTxt" BorderThickness="0" Background="Transparent" InputScope="PersonalFullName"></my:DefaultTextBox>
<TextBox LostFocus="firstNameTxt_LostFocus_1" GotFocus="firstNameTxt_GotFocus_1" Margin="0,-7" FontSize="23" x:Name="MobileTxt" BorderThickness="0" InputScope="Number" Background="Transparent" ></TextBox>
<TextBox LostFocus="firstNameTxt_LostFocus_1" GotFocus="firstNameTxt_GotFocus_1" Margin="0,-7" FontSize="23" x:Name="EmailTxt" BorderThickness="0" Background="Transparent">
</StackPanel>
</ScrollViewer>
Code behind:
void left_Click(object sender, EventArgs e)
{
int index = this.controls.IndexOf(currentControl) - 1;
if (index == -1)
{
this.Focus();
return;
}
currentControl = this.controls[index];
ContentPanel.ScrollToVerticalOffset(ContentPanel.VerticalOffset - 50);
currentControl.Focus();
}
This is a common issue on WP8. When a textbox is focused, it will translate Application 's RootVisual to bring it into view. This doesn't work well in some cases (when clipboard is on, or in your case). A workaround is manually translating RootVisual to a desired vertical offset on GotFocus and LostFocus events of TextBox.
private void TranslateRootVisualY(int yNew)
{
var rootFrame = Application.Current.RootVisual as PhoneApplicationFrame;
rootFrame.RenderTransform = new CompositeTransform() {TranslateY = yNew};
}
In your case, you can eliminate the automatic translation and make ScrollViewer scroll to desired offset in GotFocus event:
private void firstNameTxt_GotFocus_1(object sender, RoutedEventArgs e)
{
TranslateRootVisualY(0);
Dispatcher.BeginInvoke(() =>{
double destOffset;
//...calculate destination offset
ContentPanel.ScrollToVerticalOffset(destOffset);
});
}
destOffset can be calculated from sender and other function like GetRectFromCharacterIndex