How can I make a Rectangle on a canvas which is draggable? - c#

I have these three functions to trigger the events. I already have a static version of my needs, but I need a dynamically version of it.
bool captured = false;
double x_shape, x_canvas, y_shape, y_canvas;
UIElement source = null;
private void MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
source = (UIElement)sender;
Mouse.Capture(source);
captured = true;
x_shape = Canvas.GetLeft(source);
x_canvas = e.GetPosition(canvasPreview).X;
y_shape = Canvas.GetTop(source);
y_canvas = e.GetPosition(canvasPreview).Y;
}
private void MouseMove(object sender, MouseEventArgs e)
{
//MessageBox.Show("test");
if (captured)
{
double x = e.GetPosition(canvasPreview).X;
double y = e.GetPosition(canvasPreview).Y;
x_shape += x - x_canvas;
Canvas.SetLeft(source, x_shape);
x_canvas = x;
y_shape += y - y_canvas;
Canvas.SetTop(source, y_shape);
y_canvas = y;
}
}
private void MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
Mouse.Capture(null);
captured = false;
}
I have made a canvas in WPF called 'canvasPreview', I want to add the rectangle (currently in the static version I am using an ellipse) to the canvas, it must be draggable with above functions. It is already working, but it have to be dynamically.
I hope you can help me, thank you in advance!

I'm sure this sample code will help you.
XAML:
<Grid Margin="12">
<Grid.RowDefinitions>
<RowDefinition Height="auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<StackPanel Grid.Row="0" Orientation="Horizontal">
<Button x:Name="addRectangleButton" Content="Add Rectngle" Click="addRectangleButton_Click"/>
</StackPanel>
<Canvas Grid.Row="1" x:Name="canvas" Margin="0,12,0,0">
<Rectangle x:Name="rectangle" Width="100" Height="50" Fill="RoyalBlue" MouseDown="rectangle_MouseDown" MouseMove="rectangle_MouseMove" MouseUp="rectangle_MouseUp" Canvas.Left="0" Canvas.Top="0"/>
</Canvas>
</Grid>
C#:
bool drag = false;
Point startPoint;
public MainWindow()
{
InitializeComponent();
}
// this creates and adds rectangles dynamically
private void addRectangleButton_Click(object sender, RoutedEventArgs e)
{
// create new Rectangle
Rectangle rectangle = new Rectangle();
// assign properties
rectangle.Width = 100;
rectangle.Height = 50;
rectangle.Fill = new SolidColorBrush(Colors.RoyalBlue);
// assign handlers
rectangle.MouseDown += rectangle_MouseDown;
rectangle.MouseMove += rectangle_MouseMove;
rectangle.MouseUp += rectangle_MouseUp;
// set default position
Canvas.SetLeft(rectangle, 0);
Canvas.SetTop(rectangle, 0);
// add it to canvas
canvas.Children.Add(rectangle);
}
private void rectangle_MouseDown(object sender, MouseButtonEventArgs e)
{
// start dragging
drag = true;
// save start point of dragging
startPoint = Mouse.GetPosition(canvas);
}
private void rectangle_MouseMove(object sender, MouseEventArgs e)
{
// if dragging, then adjust rectangle position based on mouse movement
if (drag)
{
Rectangle draggedRectangle = sender as Rectangle;
Point newPoint = Mouse.GetPosition(canvas);
double left = Canvas.GetLeft(draggedRectangle);
double top = Canvas.GetTop(draggedRectangle);
Canvas.SetLeft(draggedRectangle, left + (newPoint.X - startPoint.X));
Canvas.SetTop(draggedRectangle, top + (newPoint.Y - startPoint.Y));
startPoint = newPoint;
}
}
private void rectangle_MouseUp(object sender, MouseButtonEventArgs e)
{
// stop dragging
drag = false;
}

Related

How to make UIElement's location transform persistent?

While looking for ways to drag around a UIElement in WPF I came across some code and have been experimenting with it. When the Element is clicked, it nicely follows the mouse, but on a subsequent drag-event, the Element reset itself to its original position.
The xaml setup: Very simple, just a named Canvas with the most original name ever and the Element, in this case a grid, called Tile1.
<Grid>
<Canvas x:Name="Canvas" Width="200" Height="300" Background="LightGray">
<Grid x:Name="Tile1">
<Border BorderBrush="Black" BorderThickness="1" Background="White">
<Control Width="25" Height="25"/>
</Border>
</Grid>
</Canvas>
</Grid>
some code-behind:
public TranslateTransform transPoint;
public Point originPoint;
public MainWindow()
{
InitializeComponent();
Tile1.MouseLeftButtonDown += Tile1_MouseLeftButtonDown;
Tile1.MouseLeftButtonUp += Tile1_MouseLeftButtonUp;
Tile1.MouseMove += Tile1_MouseMove;
}
private void Tile1_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
var myLocation = e.GetPosition(Canvas);
originPoint = new Point(myLocation.X, myLocation.Y);
transPoint = new TranslateTransform(originPoint.X, originPoint.Y);
}
private void Tile1_MouseMove(object sender, MouseEventArgs e)
{
var mouseLocation = e.GetPosition(Canvas);
if (e.LeftButton == MouseButtonState.Pressed)
{
transPoint.X = (mouseLocation.X - originPoint.X);
transPoint.Y = (mouseLocation.Y - originPoint.Y);
Tile1.RenderTransform = transPoint;
}
}
private void Tile1_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
var mouseLocationOnCanvas = e.GetPosition(Canvas);
var mouseLocationOnTile = e.GetPosition(Tile1);
//attempting to account for offset of mouse on the Tile:
var newX = mouseLocationOnCanvas.X - mouseLocationOnTile.X;
var newY = mouseLocationOnCanvas.Y - mouseLocationOnTile.Y;
Tile1.Margin = new Thickness(newX, newY, 0, 0);
}
In the original example (reference added here) A MouseUpEvent wasn't even used. Without it, my element just resets to its original position at 0,0 at every MouseDragEvent. And with it, it'll jump all over the place.
My train of thought was to somehow set the Element's current position to where the MouseUpEvent occurred.
I've been fiddling around with different things, as this particular stuff is rather new to me. Examples are: Tile1.TransformToAncestor(Canvas).Transform(mouseLocation);
I also found that VisualOffset has the information I need, so somehow it's already stored on the object, before being reset, but I haven't found a way to access it in any form.
Tile1.SetValue(VisualOffset.X = ...); or Tile1Grid.GetValue(VisualOffset);
So basically, is there a way to not have the element reset its position after RenderTransform?
I didn't find MouseLeftButtonDown event useful so I removed it:
I noticed some lags when moving the mouse that ould be annoying maybe the event needs to run asynchronously MouseMove performance slow using GetPosition.
public TranslateTransform transPoint = new TranslateTransform(0, 0);
public Point originPoint = new Point(0, 0);
public MainWindow()
{
InitializeComponent();
Tile1.MouseLeftButtonUp += Tile1_MouseLeftButtonUp;
Tile1.MouseMove += Tile1_MouseMove;
}
private void Tile1_MouseMove(object sender, MouseEventArgs e)
{
if (e.LeftButton == MouseButtonState.Pressed)
{
var mouseLocation = e.GetPosition(Canvas);
transPoint.X = (mouseLocation.X - originPoint.X);
transPoint.Y = (mouseLocation.Y - originPoint.Y);
Tile1.RenderTransform = transPoint;
}
}
private void Tile1_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
var mouseLocation = e.GetPosition(Tile1);
originPoint.X = mouseLocation.X;
originPoint.Y = mouseLocation.Y;
}
The RenderTransform seems to erratic, but I got the UIElement to stay put after moving it using the following:
private void MovableTile_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
tile.CaptureMouse();
}
with
private void MovableTile_MouseMove(object sender, MouseEventArgs e)
{
if (e.LeftButton == MouseButtonState.Pressed)
{
var tile = sender as UIElement;
var mousePosition = e.GetPosition(canvas);
Canvas.SetLeft(tile, mousePosition.X);
Canvas.SetTop(tile, mousePosition.Y);
}
}
and then
private void MovableTile_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
tile.ReleaseMouseCapture();
}
The MouseCapture was the key here. :)

WPF draw border in container

I want to draw area inside a container. For this i thought about using custom control.
My problem is that Canvas does not take up all the given space it gets. How to force it to use all available space?
What i have done is inherited from Canvas and created border element inside it:
public class DrawableCanvas : Canvas
{
private Border border;
static DrawableCanvas()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(DrawableCanvas), new FrameworkPropertyMetadata(typeof(DrawableCanvas)));
}
public DrawableCanvas()
{
this.border = new Border();
border.Background = new SolidColorBrush(Colors.Blue);
border.BorderThickness = new Thickness(1);
border.Width = 0;
border.Visibility = Visibility.Hidden;
border.Opacity = 0.3;
this.Children.Add(border);
this.MouseLeftButtonDown += DrawableCanvas_MouseLeftButtonDown;
this.MouseLeftButtonUp += DrawableCanvas_MouseLeftButtonUp;
this.MouseMove += DrawableCanvas_MouseMove;
}
private void DrawableCanvas_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
Debug.WriteLine("Left mouse up");
// release mouse
Mouse.Capture(null);
border.Width = 0;
border.Height = 100;
startPosition = 0;
}
double startPosition = 0;
private void DrawableCanvas_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
Debug.WriteLine("Left mouse down");
border.Visibility = Visibility.Visible;
// capture mouse
Mouse.Capture(this);
var point = e.GetPosition(this);
startPosition = point.X;
SetLeft(border, point.X);
}
private void DrawableCanvas_MouseMove(object sender, MouseEventArgs e)
{
if(this.IsMouseCaptured)
{
var point = e.GetPosition(this);
Debug.WriteLine("Mouse move");
// set the position to far left
SetLeft(border, Math.Min(startPosition, point.X));
// width is the difference between two points
border.Width = Math.Abs(startPosition - point.X);
Debug.WriteLine(Math.Min(startPosition, point.X));
Debug.WriteLine(border.Width);
}
}
}
And for view:
<DockPanel>
<local:DrawableCanvas>
<Rectangle Height="500" Width="500" Fill="Transparent" />
</local:DrawableCanvas>
</DockPanel>
I want something like this:
What I wanted to do is to create this control to enable selection on ui.
For this i needed a border/rectangle that will span only in width and use up all the height it gets
I ended up with this:
View:
<Window x:Class="Wpf.Test01.Stack_43281567"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:Wpf.Test01.Controls"
mc:Ignorable="d"
Title="Stack_43281567" Height="300" Width="300">
<Grid>
<local:DrawableCanvas />
</Grid>
</Window>
DrawableCanvas.cs:
public class DrawableCanvas : Canvas
{
private Border border;
static DrawableCanvas()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(DrawableCanvas), new FrameworkPropertyMetadata(typeof(DrawableCanvas)));
}
// when selection is done expose event to notify the user of selection change
public DrawableCanvas()
{
this.border = new Border();
border.Background = new SolidColorBrush(Colors.Blue);
border.BorderThickness = new Thickness(1);
border.Visibility = Visibility.Hidden;
border.Opacity = 0.3;
border.Height = this.ActualHeight;
this.Children.Add(border);
this.Background = new SolidColorBrush(Colors.Transparent);
this.MouseLeftButtonDown += DrawableCanvas_MouseLeftButtonDown;
this.MouseLeftButtonUp += DrawableCanvas_MouseLeftButtonUp;
this.MouseMove += DrawableCanvas_MouseMove;
this.SizeChanged += DrawableCanvas_SizeChanged;
}
private void DrawableCanvas_SizeChanged(object sender, SizeChangedEventArgs e)
{
border.Height = e.NewSize.Height;
}
private void DrawableCanvas_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
Debug.WriteLine("Left mouse up");
// release mouse
Mouse.Capture(null);
border.Width = 0;
startPosition = 0;
}
double startPosition = 0;
private void DrawableCanvas_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
Debug.WriteLine("Left mouse down");
border.Visibility = Visibility.Visible;
// capture mouse
Mouse.Capture(this);
var point = e.GetPosition(this);
startPosition = point.X;
SetLeft(border, point.X);
}
private void DrawableCanvas_MouseMove(object sender, MouseEventArgs e)
{
if (this.IsMouseCaptured)
{
var point = e.GetPosition(this);
Debug.WriteLine("Mouse move");
// set the position to far left
SetLeft(border, Math.Min(startPosition, point.X));
// width is the difference between two points
border.Width = Math.Abs(startPosition - point.X);
Debug.WriteLine(Math.Min(startPosition, point.X));
Debug.WriteLine(border.Width);
}
}
}

how to move a dynamic label at run time by mouse events in wpf using c#?

I want to move the label by using the Mouse_Move/Mouse_Down events.
I tried to do it like this:
private void control_MouseDown(object sender, MouseButtonEventArgs e)
{
Label l = e.Source as Label;
if (l != null)
{
l.CaptureMouse();
moving = true;
PositionInLabel = e.GetPosition(l);
}
}
private void control_MouseMove(object sender, MouseEventArgs e)
{
if (moving)
{
Point p = e.GetPosition(null);
DeltaX = p.X - BasePoint.X - PositionInLabel.X;
DeltaY = p.Y - BasePoint.Y - PositionInLabel.Y;
RaisePropertyChanged("XPosition");
RaisePropertyChanged("YPosition");
}
}
Suppose your label is on a Canvas:
public MainWindow()
{
InitializeComponent();
this.label.MouseLeftButtonDown += control_MouseLeftButtonDown;
this.label.MouseMove += control_MouseMove;
this.label.MouseLeftButtonUp += control_MouseLeftButtonUp;
}
// Keep track of the Canvas where this element is placed.
private Canvas canvas;
// Keep track of when the element is being dragged.
private bool isDragging = false;
// When the element is clicked, record the exact position
// where the click is made.
private Point mouseOffset;
private void control_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
Label l = e.Source as Label;
if (l == null)
return;
// Find the Canvas.
if (canvas == null)
canvas = (Canvas)VisualTreeHelper.GetParent(l);
// Dragging mode begins.
isDragging = true;
// Get the position of the click relative to the element
// (so the top-left corner of the element is (0,0).
mouseOffset = e.GetPosition(l);
// Capture the mouse. This way you'll keep receiving
// the MouseMove event even if the user jerks the mouse
// off the element.
l.CaptureMouse();
}
private void control_MouseMove(object sender, MouseEventArgs e)
{
Label l = e.Source as Label;
if (l == null)
return;
if (isDragging)
{
// Get the position of the element relative to the Canvas.
Point point = e.GetPosition(canvas);
// Move the element.
l.SetValue(Canvas.TopProperty, point.Y - mouseOffset.Y);
l.SetValue(Canvas.LeftProperty, point.X - mouseOffset.X);
}
}
private void control_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
Label l = e.Source as Label;
if (l == null)
return;
if (isDragging)
{
l.ReleaseMouseCapture();
isDragging = false;
}
}
Let containerCanvas be a Canvas which contains the Label; then you can utilize the _MouseMove(object sender, MouseEventArgs e) to move the label along with your mouse pointer:
Xaml code:
<Canvas Name="containerCanvas" MouseMove="containerCanvas_MouseMove" Background="Aqua" Width="525" Height="350" >
<Label Name="floatingLabel" Height="28" Width="161" Background="AliceBlue"></Label>
</Canvas>
C# code:
private void containerCanvas_MouseMove(object sender, MouseEventArgs e)
{
Point p = Mouse.GetPosition(Application.Current.MainWindow);
floatingLabel.Margin = new Thickness(p.X, p.Y, 0, 0);
}
I have done a sample code. Check this. It should work.
XAML :
<UserControl HorizontalAlignment="Left" x:Class="WPFDiagramDesignerControl.Components.TestApp"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Height="100" Width="100" IsEnabled="True">
<Grid >
<Canvas x:Name="MyDesigner">
<TextBox x:Name="txtBox" IsEnabled="True" Background="AntiqueWhite" Margin="10,10,10,10" TextWrapping="Wrap"> </TextBox>
</Canvas>
</Grid>
Code Behind :
public TestApp()
{
InitializeComponent();
txtBox.MouseDoubleClick+=new MouseButtonEventHandler(control_MouseDoubleClick);
txtBox.MouseMove+=new MouseEventHandler(control_MouseMove);
txtBox.PreviewMouseDown+=new MouseButtonEventHandler(control_PreviewMouseDown);
txtBox.PreviewMouseUp+=new MouseButtonEventHandler(control_PreviewMouseUp);
txtBox.Cursor = Cursors.SizeAll;
}
private void control_MouseMove(object sender, RoutedEventArgs e)
{
if (isClicked)
{
Point mousePos = Mouse.GetPosition(parentCanvas);
parentItem = this.Parent as DesignerItem;
parentCanvas = parentItem.Parent as DesignerCanvas;
Point relativePosition = Mouse.GetPosition(parentCanvas);
DesignerCanvas.SetLeft(this, DesignerCanvas.GetLeft(this) - (startPoint.X - mousePos.X));
DesignerCanvas.SetTop(this, DesignerCanvas.GetTop(this) - (startPoint.Y - mousePos.Y));
}
}
private void control_PreviewMouseDown(object sender, RoutedEventArgs e)
{
if (!isClicked)
{
isClicked = true;
parentItem = this.Parent as DesignerItem;
parentCanvas = parentItem.Parent as DesignerCanvas;
startPoint = Mouse.GetPosition(parentCanvas);
}
}
private void control_PreviewMouseUp(object sender, RoutedEventArgs e)
{
isClicked = false;
}

WPF: How to translateTransform a rectangle?

I'm trying to move a rectangle drawn in Canvas by mouse (drag and drop).
When I click on the Rectangle and move the mouse (keep clicking) to a new position it's OK:
But when I click on it again and move the mouse just a bit the Rectangle move to old position:
I don't know why it is. Can anybody give me some explaination?
Here is my code (all parameters have been assigned and initialized).
Thanks in advance!
private void MyCanvas_MouseMove_1(object sender, MouseEventArgs e)
{
if (e.RightButton == MouseButtonState.Pressed && e.OriginalSource is Shape)
{
p2 = e.GetPosition(MyCanvas);
TranslateTransform tf = new TranslateTransform(p2.X - p1.X, p2.Y - p1.Y);
_MyTestRect.RenderTransform = tf;
}
}
private void MyCanvas_MouseRightButtonDown(object sender, MouseButtonEventArgs e)
{
if (e.OriginalSource is Shape)
{
p1 = e.GetPosition(MyCanvas);
}
}
Mvvm Behavior Approach add the refference to:
System.Windows.Interactivity.
In XAML:
<Canvas x:Name="MyCanvas" Background="#00FFFFFF">
<i:Interaction.Behaviors>
<!--soSandBox is the reffrence to the behavior-->
<soSandBox:MoveElementsInCanvasBehavior/>
</i:Interaction.Behaviors>
<Rectangle x:Name="_MyTestRect1" Fill="Tomato" Width="50" Height="50"/>
<Rectangle x:Name="_MyTestRect2" Fill="Tomato" Width="50" Height="50"/>
<Rectangle x:Name="_MyTestRect3" Fill="Tomato" Width="50" Height="50"/></Canvas>
Behavior code:
protected override void OnAttached()
{
base.OnAttached();
AssociatedObject.MouseLeftButtonDown += AssociatedObjectOnMouseLeftButtonDown;
AssociatedObject.MouseLeftButtonUp += AssociatedObjectOnMouseLeftButtonUp;
AssociatedObject.MouseMove += AssociatedObjectOnMouseMove;
}
private void AssociatedObjectOnMouseMove(object sender, MouseEventArgs e)
{
if (_shape != null && _shape.IsMouseCaptured)
{
_p2 = e.GetPosition(AssociatedObject);
_shape.SetValue(Canvas.TopProperty, _p2.Y - _originalOffsetFromTop);
_shape.SetValue(Canvas.LeftProperty, _p2.X - _originalOffsetFromLeft);
}
}
private void AssociatedObjectOnMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
if (_shape == null) return;
_shape.ReleaseMouseCapture();
_shape = null;
}
private double GetDist(double originalValue, double newValue)
{
if (double.IsNaN(originalValue) || double.IsInfinity(originalValue))
return Math.Abs(newValue - 0);
return Math.Abs(newValue - originalValue);
}
private void AssociatedObjectOnMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
_shape = e.OriginalSource as Shape;
if (_shape != null)
{
_p1 = e.GetPosition(AssociatedObject);
_shape.CaptureMouse();
_originalOffsetFromTop = GetDist((double)_shape.GetValue(Canvas.TopProperty), _p1.Y);
_originalOffsetFromLeft = GetDist((double)_shape.GetValue(Canvas.LeftProperty), _p1.X);
}
}
protected override void OnDetaching()
{
base.OnDetaching();
AssociatedObject.MouseLeftButtonDown -= AssociatedObjectOnMouseLeftButtonDown;
AssociatedObject.MouseLeftButtonUp -= AssociatedObjectOnMouseLeftButtonUp;
AssociatedObject.MouseMove -= AssociatedObjectOnMouseMove;
}
Summary:
This way you can put inside the canvas as much elements as you wish, and when you click the element (and when this element is a shape) you will be able to move it.
Translate Transform XAML:
<Canvas x:Name="MyCanvas" Background="#00FFFFFF">
<i:Interaction.Behaviors>
<!--convert event to command mechanism-->
<soSandBox:CanvasMouseEventObservingBehavior
OnMouseMoveAction="{Binding OnMouseMoveAction, UpdateSourceTrigger=PropertyChanged}"
OnMouseRightButtonDownAction="{Binding OnMouseRightButtonDownAction, UpdateSourceTrigger=PropertyChanged}"
OnMouseRightButtonUpAction="{Binding OnMouseRightButtonUpAction, UpdateSourceTrigger=PropertyChanged}"/>
</i:Interaction.Behaviors>
<Rectangle x:Name="_MyTestRect1" Fill="Tomato" Width="50" Height="50">
<Rectangle.RenderTransform>
<TransformGroup>
<TranslateTransform X="{Binding TranslateTransformX, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}"
Y="{Binding TranslateTransformY, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}"></TranslateTransform>
</TransformGroup>
</Rectangle.RenderTransform>
</Rectangle></Canvas>
Translate Transform view model (translation related code):
private void RightMouseUp(Point obj)
{
_originalPoint = obj;
_currentOffsetByX = GetDist(_currentOffsetByX, obj.X);
_currentOffsetByY = GetDist(_currentOffsetByY, obj.Y);
}
private void RightMouseDown(Point obj)
{
_originalPoint = obj;
_currentOffsetByX = GetDist(_currentOffsetByX, obj.X);
_currentOffsetByY = GetDist(_currentOffsetByY, obj.Y);
}
private void MouseMoved(Point obj)
{
TranslateTransformX = obj.X - _currentOffsetByX;
TranslateTransformY = obj.Y - _currentOffsetByY;
}
private double GetDist(double originalValue, double newValue)
{
if (double.IsNaN(originalValue) || double.IsInfinity(originalValue))
return Math.Abs(newValue - 0);
return Math.Abs(newValue - originalValue);
}
public double TranslateTransformY
{
get { return _translateTransformY; }
set
{
_translateTransformY = value;
OnPropertyChanged();
}
}
public double TranslateTransformX
{
get { return _translateTransformX; }
set
{
_translateTransformX = value;
OnPropertyChanged();
}
}
Regards
You should not create the transform every time otherwise you reset the translation.
Create a TranslateTransform if none exist.
Then cumulate the translations inside.
Regards
Try just using the Canvas.SetTop and Canvas.SetLeft.
Rectangle myRectangle = new Rectangle();
myRectangle += myRectangle_MouseLeftButtonDown;
void myRectangle_MouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
myRectangle.MouseMove += origin_MouseMove;
}
void myRectangle_MouseMove(object sender, System.Windows.Input.MouseEventArgs e)
{
Point p = new Point()
{
// Just round the coordinates
X = Math.Round(e.GetPosition(canvas).X, 0, MidpointRounding.AwayFromZero),
Y = Math.Round(e.GetPosition(canvas).Y, 0, MidpointRounding.AwayFromZero),
};
Canvas.SetTop(myRectangle, p.Y);
Canvas.SetLeft(myRectangle, p.X);
myRectangle.MouseLeftButtonUp += myRectangle_MouseLeftButtonUp;
}
void myRectangle_MouseLeftButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
myRectangle.MouseMove -= origin_MouseMove;
myRectangle.MouseLeftButtonUp -= origin_MouseLeftButtonUp;
}

How to access the name canvas to MainPage from another class

I'm C# newbie. I want to access my Canvas in MainPage.xaml from class CS_Line, but i can't do it. How to call the name's canvas in class CS_Line.cs.
MainPage.xaml:
<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<Canvas x:Name="MyCanvas" HorizontalAlignment="Left" Height="573" Margin="154,76,0,0" VerticalAlignment="Top" Width="913" Background="White"/>
</Grid>
in CS_Line.cs:
class CS_Line
{
//attribute
InkManager _inkKhaled = new Windows.UI.Input.Inking.InkManager();
private uint _penID;
private uint _touchID;
private Point _previousContactPt;
private Point currentContacPt;
private double x1;
private double y1;
private double x2;
private double y2;
//method
private void MyCanvas_PointerPressed(object sender, PointerRoutedEventArgs e)
{
PointerPoint pt = e.GetCurrentPoint(MyCanvas); *//====>>>>> can't access the MyCanvas*
_previousContactPt = pt.Position;
PointerDeviceType pointerDevType = e.Pointer.PointerDeviceType;
if (pointerDevType == PointerDeviceType.Pen ||
pointerDevType == PointerDeviceType.Mouse &&
pt.Properties.IsLeftButtonPressed)
{
_inkKhaled.ProcessPointerDown(pt);
_penID = pt.PointerId;
e.Handled = true;
}
else if (pointerDevType == PointerDeviceType.Touch)
{
}
}
You can get MyCanvas from sender.
private void MyCanvas_PointerPressed(object sender, PointerRoutedEventArgs e)
{
Canvas myCanvas = sender as Canvas; // Here's your MyCanvas object
PointerPoint pt = e.GetCurrentPoint(myCanvas);
_previousContactPt = pt.Position;

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