I wrote a very simple newbie app with a 6-sided polyhedron (a "box") which rotates 180 degrees when I click a button. and then rotates back again on the next click. Every rotation grabs another 90MB and it doesn't let go until I close the app. The box is defined in the XAML. The Storyboard, DoubleAnimation and PropertyPath, etc, are all created ONCE, in the constructor. The button code looks like this:
private void button_Storyboard1_Click(object sender, RoutedEventArgs e)
{
GC.Collect();
if (_bFront)
{
_myDoubleAnimation.From = 0;
_myDoubleAnimation.To = 180;
_bFront = false;
}
else
{
_myDoubleAnimation.From = 180;
_myDoubleAnimation.To = 0;
_bFront = true;
}
_myDoubleAnimation.Duration = _Duration;
Storyboard.SetTargetName(_myDoubleAnimation, "rotate_me");
Storyboard.SetTargetProperty(_myDoubleAnimation, _PropP);
_sb.Children.Add(_myDoubleAnimation);
_sb.Begin(this.viewport3D1);
}
After a few rotations I'm out of memory! What's going on?
Could be totally wrong here, but aren't you adding _myDoubleAnimation to _sb.Children on each click, instead of just updating it?
Related
Just wanted to know if its possible to do it like winform? Where i can add a button to where i last click. I tried googling but dont think i found anything similar. Will the grid for WPF be an issue where i can place my button freely on click?
Idea is to click on the coordinate and then press the button to add an image/button.
Below is what i did so far, havent added the button function yet, just wanted to know if its possible to do it as i have done so for winform before.
public MainWindow()
{
InitializeComponent();
MainWindow.xCoord = -1;
MainWindow.yCoord = -1;
}
private void AddEvent_Click(object sender, EventArgs e)
{
if (MainWindow.xCoord < 0 || MainWindow.yCoord < 0)
{
MessageBox.Show("Please select a coordinate");
return;
}
}
public void MainWindow_Mouseup(object sender, MouseEventArgs e)
{
Point p = e.GetPosition(this);
textBox1.Text = "x-" + p.X + "y- " + p.Y;
MainWindow.xCoord = (int)p.X;
MainWindow.yCoord = (int)p.Y;
}
Yes you can do it, and you would need to use a Canvas to draw the button. This can be contained inside the Grid, but AFAIK the Canvas is the only way to have a sort of "Draw" function with UI Controls.
You will want to capture the MouseUp event within the Canvas and then add your button at the location you can retrieve in the Handler.
XAML:
<Grid>
<Canvas x:Name="ButtonCanvas" MouseUp="ButtonCanvas_MouseUp"/>
</Grid>
Code Behind:
private void ButtonCanvas_MouseUp(object sender, MouseButtonEventArgs e)
{
Point p = e.GetPosition(ButtonCanvas);
textBox1.Text = "x-" + p.X + "y- " + p.Y;
MainWindow.xCoord = (int)p.X;
MainWindow.yCoord = (int)p.Y;
}
Then just have a function that will create and add a Button at these coordinates (I will assume you have some sort of "Add Button to Canvas" Button):
private void AddButtonToCoord_Click(object sender, EventArgs e)
{
var button = new Button();
//--change button properties if you want--
//add to canvas
Canvas.Childen.Add(button);
//set Control coordinates within the canvas
Canvas.SetLeft(button, MainWindow.xCoord);
Canvas.SetTop(button, MainWindow.yCoord);
}
You can get fancier for your needs, like if you want the center of the button to be at the Coordinates, or if you want to prevent the Button from being drawn outside the canvas (like if the user click the very bottom right corner). But this should be enough to get a minimum working example.
I've implemented dragging to external applications in my WPF application and it works. However after dropping onto a target I continue to get spurious drop events on my application after I bring the cursor back onto it. This continues 'forever'.
As far as I can tell from online searches after calling DragDrop.DoDragDrop() I shouldn't need to do anything else. I have tried adding some code to cancel the event but it has no effect even though it runs:
private void UIElement_OnPreviewMouseMove(object sender, MouseEventArgs e)
{
var frameworkElement = (FrameworkElement) sender;
if (frameworkElement.DataContext is IDragSource dragSource)
{
var position = e.GetPosition((IInputElement) sender);
if (dragSource.DragCanStart(new Point {X = position.X, Y = position.Y}))
{
var dragStart = true;
void OnFrameworkElementOnQueryContinueDrag(object o, QueryContinueDragEventArgs e2)
{
if (!dragStart)
{
e2.Action = DragAction.Cancel;
frameworkElement.QueryContinueDrag -= OnFrameworkElementOnQueryContinueDrag;
}
}
frameworkElement.QueryContinueDrag += OnFrameworkElementOnQueryContinueDrag;
dragSource.DragInitiate(sender);
e.Handled = true;
dragStart = false;
}
}
}
I've tracked it down to our code initiating multiple drags. Our guard logic wasn't quite good enough which meant every time the mouse moved over the source component it triggered another drag.
Tricky to debug :)
I have a WPF app with two canvases which overlay each other . . .
<Canvas Name="GeometryCnv" Canvas.Top="0" Canvas.Left="0" Margin="10,21,315,251" />
<Canvas Name="ROIcnv" Background ="Transparent" Canvas.Top="0" Canvas.Left="0" Margin="10,21,315,251" MouseDown="ROIcnvMouseDown" MouseUp="ROIcnvMouseUp" MouseMove="ROIcnvMouseMove"/>
I draw some geometry on the first canvas and I draw a rectangle to denote a Region on Interest (ROI) on the second one, using the Mouse-down event to start the drawing, Mouse-move events while drawing (resizing or positioning) the rectangle, and the Mouse-up event to end the drawing.
Except that it's not handling the events reliably. It gets the initial Mouse-down event to start it. It gets Mouse-move events continuously - regardless of whether the mouse is moving - and it does not get the Mouse-up event at all, nor does it get any subsequent mouse down events, say if I double-click the mouse.
The event-handler code looks like this . . .
private void ROIcnvMouseDown(object sender, MouseButtonEventArgs e)
{
MouseLineBegin = Mouse.GetPosition(ROIcnv);
bMouseDown = true;
}
private void ROIcnvMouseUp(object sender, MouseButtonEventArgs e)
{
MouseLineEnd = Mouse.GetPosition(ROIcnv);
bMouseDown = false;
}
private void ROIcnvMouseMove(object sender, MouseEventArgs e)
{
iMM++; // counting mouse move events
ROIcnv.Children.Clear(); // clear the ROI canvas
if (bMouseDown) // if we're drawing now
{
MouseLineEnd = Mouse.GetPosition(ROIcnv);
// get the upper left and lower right = coords from the beginning and end points . . .
int ulx = 0;
int uly = 0;
int lrx = 0;
int lry = 0;
if (MouseLineEnd.X >= MouseLineBegin.X)
{
ulx = (int) MouseLineBegin.X;
lrx = (int) MouseLineEnd.X;
}
else
{
lrx = (int)MouseLineBegin.X;
ulx = (int)MouseLineEnd.X;
}
if (MouseLineEnd.Y >= MouseLineBegin.Y)
{
uly = (int)MouseLineBegin.Y;
lry = (int)MouseLineEnd.Y;
}
else
{
lry = (int)MouseLineBegin.Y;
uly = (int)MouseLineEnd.Y;
}
int h = Math.Abs(lry-uly);
int w = Math.Abs(lrx-ulx);
var rect = new Path
{
Data = new RectangleGeometry(new Rect(ulx, uly, w, h)),
Stroke = Brushes.Black,
StrokeThickness = 2
};
ROIcnv.Children.Add(rect);
}
}
... I've tried suspending the mouse in mid-air and resting it on towels to eliminate any vibrations that might cause spurious move events with no benefit, any anyway that wouldn't account for not getting subsequent up and down events.
Note: I tried this on another computer with exactly the same results.
You'll have much better responses if you provide a minimal, working example of your problem (specifically both your ROIcnvMouseDown and ROIcnvMouseUp methods are missing as are all of your property declarations). The problem is possibly due to your newly-created Path object interfering with the mouse messages, if so then it can be fixed by setting it's IsHitTestVisible property to false. Need a minimal example to determine this for sure though.
UPDATE: Sorry, my bad, I must have stuffed up the cut-n-paste into my test app. Try capturing the mouse in response to the mouse down event:
private void ROIcnvMouseDown(object sender, MouseButtonEventArgs e)
{
MouseLineBegin = Mouse.GetPosition(ROIcnv);
bMouseDown = true;
Mouse.Capture(sender as IInputElement);
}
And of course you need to release it in response to MouseUp:
private void ROIcnvMouseUp(object sender, MouseButtonEventArgs e)
{
MouseLineEnd = Mouse.GetPosition(ROIcnv);
bMouseDown = false;
Mouse.Capture(sender as IInputElement, CaptureMode.None);
ROIcnv.Children.Clear();
}
The other thing I've done is call ROIcnv.Children.Clear(); in response to MouseUp as I assume you no longer want the selection rectangle to be visible. On my machine this doesn't result in any spurious mouse move events.
Does that answer the question?
Clicking the middle mouse button (aka: mouse wheel) and then moving the mouse down slightly lets users scroll in IE, and most Windows apps. This behavior appears to be missing in WPF controls by default? Is there a setting, a workaround, or something obvious that I'm missing?
I have found how to achieve this using 3 mouse events (MouseDown, MouseUp, MouseMove). Their handlers are attached to the ScrollViewer element in the xaml below:
<Grid>
<ScrollViewer MouseDown="ScrollViewer_MouseDown" MouseUp="ScrollViewer_MouseUp" MouseMove="ScrollViewer_MouseMove">
<StackPanel x:Name="dynamicLongStackPanel">
</StackPanel>
</ScrollViewer>
<Canvas x:Name="topLayer" IsHitTestVisible="False" />
</Grid>
It would be better to write a behaviour instead of events in code-behind, but not everyone has the necessary library, and also I don't know how to connect it with the Canvas.
The event handlers:
private bool isMoving = false; //False - ignore mouse movements and don't scroll
private bool isDeferredMovingStarted = false; //True - Mouse down -> Mouse up without moving -> Move; False - Mouse down -> Move
private Point? startPosition = null;
private double slowdown = 200; //The number 200 is found from experiments, it should be corrected
private void ScrollViewer_MouseDown(object sender, MouseButtonEventArgs e)
{
if (this.isMoving == true) //Moving with a released wheel and pressing a button
this.CancelScrolling();
else if (e.ChangedButton == MouseButton.Middle && e.ButtonState == MouseButtonState.Pressed)
{
if (this.isMoving == false) //Pressing a wheel the first time
{
this.isMoving = true;
this.startPosition = e.GetPosition(sender as IInputElement);
this.isDeferredMovingStarted = true; //the default value is true until the opposite value is set
this.AddScrollSign(e.GetPosition(this.topLayer).X, e.GetPosition(this.topLayer).Y);
}
}
}
private void ScrollViewer_MouseUp(object sender, MouseButtonEventArgs e)
{
if (e.ChangedButton == MouseButton.Middle && e.ButtonState == MouseButtonState.Released && this.isDeferredMovingStarted != true)
this.CancelScrolling();
}
private void CancelScrolling()
{
this.isMoving = false;
this.startPosition = null;
this.isDeferredMovingStarted = false;
this.RemoveScrollSign();
}
private void ScrollViewer_MouseMove(object sender, MouseEventArgs e)
{
var sv = sender as ScrollViewer;
if (this.isMoving && sv != null)
{
this.isDeferredMovingStarted = false; //standard scrolling (Mouse down -> Move)
var currentPosition = e.GetPosition(sv);
var offset = currentPosition - startPosition.Value;
offset.Y /= slowdown;
offset.X /= slowdown;
//if(Math.Abs(offset.Y) > 25.0/slowdown) //Some kind of a dead space, uncomment if it is neccessary
sv.ScrollToVerticalOffset(sv.VerticalOffset + offset.Y);
sv.ScrollToHorizontalOffset(sv.HorizontalOffset + offset.X);
}
}
If to remove the method calls AddScrollSign and RemoveScrollSign this example will work. But I have extended it with 2 methods which set scroll icon:
private void AddScrollSign(double x, double y)
{
int size = 50;
var img = new BitmapImage(new Uri(#"d:\middle_button_scroll.png"));
var adorner = new Image() { Source = img, Width = size, Height = size };
//var adorner = new Ellipse { Stroke = Brushes.Red, StrokeThickness = 2.0, Width = 20, Height = 20 };
this.topLayer.Children.Add(adorner);
Canvas.SetLeft(adorner, x - size / 2);
Canvas.SetTop(adorner, y - size / 2);
}
private void RemoveScrollSign()
{
this.topLayer.Children.Clear();
}
Example of icons:
And one last remark: there are some problems with the way Press -> Immediately Release -> Move. It is supposed to cancel scrolling if a user clicks the mouse left button, or any key of keyboard, or the application looses focus. There are many events and I don't have time to handle them all.
But standard way Press -> Move -> Release works without problems.
vorrtex posted a nice solution, please upvote him!
I do have some suggestions for his solution though, that are too lengthy to fit them all in comments, that's why I post a separate answer and direct it to him!
You mention problems with Press->Release->Move. You should use MouseCapturing to get the MouseEvents even when the Mouse is not over the ScrollViewer anymore. I have not tested it, but I guess your solution also fails in Press->Move->Move outside of ScrollViewer->Release, Mousecapturing will take care of that too.
Also you mention using a Behavior. I'd rather suggest an attached behavior that doesn't need extra dependencies.
You should definately not use an extra Canvas but do this in an Adorner.
The ScrollViewer itsself hosts a ScrollContentPresenter that defines an AdornerLayer. You should insert the Adorner there. This removes the need for any further dependency and also keeps the attached behavior as simple as IsMiddleScrollable="true".
In this case when user click some UIElement I want this element yo be surrounded by dashed border. If there is some other object surrounded then this code removes it first.
Everything is fine but "private void activateElem" fires twice and I have no idea why. Maybe somebody can help, I really have no more ideas.
Anybody knows some ideas to debug issues like this? Maybe there is some way to print out all events queue. There is silverlight spy but I think it doesn't work for windows phone 7.
My code:
public class ManipulationEngine
{
private Canvas sheet;
private static FrameworkElement current_active_element;
public ManipulationEngine(Canvas sheet)
{
this.sheet = sheet;
foreach (FrameworkElement elem in sheet.Children)
{
elem.MouseLeftButtonUp += new MouseButtonEventHandler(activateElem);
}
}
private void activateElem(object sender, MouseButtonEventArgs e)
{
FrameworkElement elem = sender as FrameworkElement;
if (current_active_element != null)
{
desactivateElem();
}
Grid grid = new Grid();
Rectangle recentagle = new Rectangle();
grid.SetValue(Canvas.TopProperty, (double)elem.GetValue(Canvas.TopProperty) - 10);
grid.SetValue(Canvas.LeftProperty, (double)elem.GetValue(Canvas.LeftProperty) - 10);
DoubleCollection stroke = new DoubleCollection();
stroke.Add(4);
stroke.Add(2);
recentagle.StrokeDashArray = stroke;
grid.Children.Add(recentagle);
sheet.Children.Remove(elem);
elem.Margin = new Thickness(10);
grid.Children.Add(elem);
sheet.Children.Add(grid);
current_active_element = elem;
}
private void desactivateElem()
{
if (current_active_element != null)
{
Grid grid = VisualTreeHelper.GetParent(current_active_element) as Grid;
grid.Children.Remove(current_active_element);
sheet.Children.Remove(grid);
current_active_element.SetValue(Canvas.TopProperty, (double)grid.GetValue(Canvas.TopProperty) + 10);
current_active_element.SetValue(Canvas.LeftProperty, (double)grid.GetValue(Canvas.LeftProperty) + 10);
current_active_element.Margin = new Thickness(0);
sheet.Children.Add(current_active_element);
current_active_element = null;
}
}
I'd really advise looking into the Parts and States model. You may be able to do this with a button, or perhaps a radio button.
Usually if you're coding changes to the visual tree, you're not doing it right.
Karen Corby dealt with this very clearly at MIX08, take a look!
http://archive.visitmix.com/blogs/2008Sessions/T20/
Luke