Develop Reference

Unity 2D Setting the value of a Scrollbar to 0

I just wanted to set the value of the scrollbar of my scrollview object to 0 every time a new text object is created. This way the newest object would always remain at the bottom without needing to scroll down (think of the chat of a video game for example). My problem is that for some reason the program is setting the value to 0 and then creating the text object, so it keeps the 2nd newest object at the bottom of the scrollview.
My code:
//Creates the Text objects
private GameObject GenerateTextObject(string content)
{
//Creates the Text objects
GameObject messagePrefab = Instantiate(MessagePrefab);
Text textComponent = messagePrefab.GetComponent<Text>();
//Sets the content of the text and parent
textComponent.text = content;
messagePrefab.transform.SetParent(ContentPanel.transform, false);
ScrollbarVertical.value = 0;
return messagePrefab;
}
In the code I am setting the value at the end of the function, but still sets the value of the scrollbar to 0 (properly moving the scrollview to the bottom) before the object is created.
https://gyazo.com/897982521f13d7792ec26540490a40c0
In the Gyazo picture you can see how it doesn't scroll all the way down.
I have tried using a coroutine and waitForEndFrame aswell as waitforseconds(1), but none seem to work.
Edit: when loading up Unity and sending new messages to the scrollview, I see the scrollbar go all the way down and then really quickly move up just a bit hiding the new text object.

What you can do is create a new Scroll View and follow these steps:
The result is from calling GenerateTextObject(Time.time.ToString()); every second.
private GameObject GenerateTextObject(string content)
{
//Creates the Text objects
GameObject messagePrefab = Instantiate(MessagePrefab);
Text textComponent = messagePrefab.GetComponent<Text>();
//Sets the content of the text and parent
textComponent.text = content;
messagePrefab.transform.SetParent(ContentPanel.transform, false);
//Force reset to the bottom on each message
//ScrollbarVertical.value = 0;
return messagePrefab;
}

I have not come up with a proper fix for this problem (I honestly do not know the cause of problem), but I have put together a little work-around for this situation.
To do this I simply created a small function:
public void Testing()
{
if (testing == true)
{
ScrollbarVertical.value = 0;
testing = false;
}
}
This would be attached to the built-in functionality of scrollbars "On Value Changed (Single)". In order to allow this to work, I just change the bool "testing" to true after creating a text object on GenerateTextObject(string content).
This fix is really ugly, and probably would cause more problems in the near future, but for now, it is a quick and dirty solution for this problem.

Sorry to necro this, but I had a similar problem and googling couldn't find a good answer. So I'm posting the solution that I found.
I tried to change the scrollbar value to 1 or 0, depending on the direction, so that everytime I open a UI panel, it'll start at the top. But no matter what I did, nothing seemed to work.
So my solution is to change the Y position of the content instead of the scrollbar value.
My scrollbar direction is set at bottom to top. Then I take the sizeDelta of the content, divide it by 2, (since I need the value of 1 for the scrollbar.value). I then multiplied it by -1 (if I dont, it'll start at the bottom). Then I set that value as the Y position of the content.
So far it works like a charm everytime I open my UI panel.
Hope this helps anyone looking for a solution.

Horizontal Scroll Bar in Oxyplot WPF

I'm trying to implement a utility for showing throughput over time in a system, and am using Oxyplot to visualise the data.
Currently, zoom and pan are working as expected, but I would like some visual indication to the user which clearly shows whether the graph can be zoomed or panned.
After ditching the idea of using a scroll bar (being neither able to accurately get the position of the visible section of the graph, nor correctly position the thumb of the scroll bar releative to the chart), I have settled on using icons to show whether there is any data on the chart which is hidden to the left or rightmost side.
I would like these icons to work as buttons which allow the user to page left and right on the graph, however as with all things OxyPlot related, the implementation is far more complex than it first seems.
I'm using the WPF implementation, which uses a ViewModel representing the overall data set, with each series item represented by its own model.
This effectively renders almost every tutorial useless as the WPF implementation is significantly different to the basic OxyPlot package.
Currently, the code behind in the view handles the click on the page left/right buttons. I cannot put this in my ViewModel as it must interract directly with the PlotControl object.
private void btnPageRight_Click(object sender, RoutedEventArgs e) {
CategoryAxis axis = (CategoryAxis)PlotControl.ActualModel.Axes[0];
double xAxisMin = axis.ActualMinimum;
double xAxisMax = axis.ActualMaximum;
double visibleSpan = xAxisMax - xAxisMin;
double newMinOffset = xAxisMax + visibleSpan;
PlotControl.Axes[0].Minimum = newMinOffset;
PlotControl.Axes[0].Maximum = newMinOffset + visibleSpan;
PlotControl.ActualModel.InvalidatePlot(true);
}
As it stands, the above code throws no errors, but it does not work either.
If anybody can advise a possible way to make OxyPlot scroll to a given position using just code behind, I would be grateful.
As a last resort, I have pondered trying to simulate a mouse drag event to make this finicky beast behave.
I find the need to work around the problem in that way quite offensive, but desparation leads to odd solutions...

In case anybody else runs into this issue, the following snippet will scroll the graph in pages based on the number of columns visible on the graph at the time.
The snippet takes the number of visible columns as the viewport, and will move the visible area by the viewport size.
Although this applies to the WPF implementation, the only way I could find to make this work was to run this method from the code behind in the View containing the OxyPlot chart.
This should work correctly regardless of the zoom amount at the time.
The CategoryAxis reference must be obtained from the ActualModel as the WPF.Axis does not provide the ActualMinumum and ActualMaximum needed to calculate the viewable area.
The visibleSpan in this case represents the number of columns, with panStep denoting the amount to pan by in pixels.
private void ScrollInPages() {
//To zoom on the X axis.
CategoryAxis axis = (CategoryAxis)PlotControl.ActualModel.Axes[0];
double visibleSpan = axis.ActualMaximum - axis.ActualMinimum;
double panStep = 0;
//Scrolling the chart - comment out as appropriate
//Scroll right one page
panStep = axis.Transform(0 - (axis.Offset + visibleSpan));
//Scroll left one page
panStep = axis.Transform(axis.Offset + visibleSpan);
axis.Pan(panStep);
PlotControl.InvalidateFlag++;
}

Visual C# creating list of items

I need to make an application that shows codes that update from time to time.
Now I got the back-end part covered but I am completely new to the front end part.
I'd basicly like it took look something like this:
Now the idea is that I'll have a List that holds items that should be converted to elements in the below visual list.. The logo is something I staticly added and that is anchored to the left top corner, I'd like to create the rest of the elemnents dynamically (I have a timed event loop to check if the list has changed, etc)
So I made the following method as a starting point:
private void createOTPEntry()
{
Rectangle entry = new Rectangle();
entry.Name = "entry1";
entry.Stroke = new SolidColorBrush(Color.FromRgb(0, 111, 0));
entry.Fill = new SolidColorBrush(Color.FromRgb(243, 86, 13));
entry.Height = 65;
entry.Width = 497;
Thickness margin = entry.Margin;
margin.Left = 10;
margin.Top = 83;
entry.Margin = margin;
entry.BringIntoView();
}
Now this isn't relative yet to the logo or anything.. But it's supposed to atleast be a white rectangle with an orange border.. And it's not showing. I tried to find if my rectangle object has like a "show" or "draw" method but it doesn't.. And I'm still miles away from what I really want..
So the logic of what I want:
Loop that goes over list elements and draws the visual list elements, probably a Rectangle containing 2 TextBoxes or Labels (one of the labels will change)
These elements will be added to another Container? that has a scrollbar in case there are to many elements.
I'd like some help of possible on what control do I choose to add the elements to? (the container witht he scrollbar?). How exactly do I show my rectangle? Is there an easy way to make them kinda automaticly space when I add them to the "parent control" (the scrollable container).
Thanks in advance for giving me a jump start!

Silverlight different behaviour when being run from website

I am working on a simple Silverlight application. The point of application is to display data loaded from XML file. Data consists of String "password" and Integer "passwordCount". Each loaded position is displayed as a coloured square and whenever user moves mouse over this square it is resized to "passwordCount/10" pixel width or height and the "password" string is displayed on it. Here is an example:
On Mouseover:
Everything works fine if I run it via VisualStudio Run button. The problem is that when I place the script on website, tiles resize in the wrong direction (they become smaller instead of bigger). The text is not displayed either. I don't have the faintest idea why. Silverlight on website opens in a separate window and it looks like that on mouseover:
(source: screenshu.com)
Here is the function I use to animate tiles:
public void rectangle_MouseEnter(object sender, MouseEventArgs e)
{
sbMouseON = new Storyboard();
DoubleAnimation sizeAnimation = new DoubleAnimation();
sizeAnimation.To = passwordCount/10; //passwordCount is always greater than 1000
sizeAnimation.Duration = new Duration(TimeSpan.FromMilliseconds(300));
Storyboard.SetTarget(sizeAnimation, (Rectangle)sender);
Storyboard.SetTargetProperty(sizeAnimation, new PropertyPath(direction));
sbMouseON.Children.Add(sizeAnimation);
Canvas.SetZIndex(rect, 2); //move rectangle up to make animation visible
DrawTextBlock();
sbMouseON.Begin();
}

Mods: Can't Add Comment so posting as answer
Here I am assuming that the "direction" you are passing in the TargetProperty is "(FrameworkElement.Width)" to increase the width of the rectangle.
If so only Logical Reason a Object can reduce in size is "sizeAnimation.To" property you are setting is setting the value which is smaller than the actual width of the object.
What is this DrawTextBlock() doing ? is there any code in there which can change the behavior of animation ?

The problem solved itself. I've just copied all files onto server and it works great. Looks like it was some Windows problem. Thank you for your interest #Abhinav.

Drawing things on a Canvas

How would I draw something on a Canvas in C# for Windows Phone?
Okay, let me be a little more clear.
Say the user taps his finger down at 386,43 on the canvas. (the canvas is 768 by 480)
I would like my application to be able to respond by placing a red dot at 386,43 on the canvas.
I have no prior experience with Canvas whatsoever.
If this is too complex to be answered in one question (which it probably is), please give me links to other websites with Canvas and Drawing articles.

There are various ways of doing this. Depending on the nature of the red dot, you could make it a UserControl. For a basic circle, you can simply handle your canvas' ManipulationStarted event.
private void myCanvas_ManipulationStarted(object sender, ManipulationStartedEventArgs e)
{
Ellipse el = new Ellipse();
el.Width = 10;
el.Height = 10;
el.Fill = new SolidColorBrush(Colors.Red);
Canvas.SetLeft(el, e.ManipulationOrigin.X);
Canvas.SetTop(el, e.ManipulationOrigin.Y);
myCanvas.Children.Add(el);
}

I think you need to approach the problem differently. (I'm not including code on purpose, because of that).
Forms and controls in an Windows applications (including Phone) can be refreshed for several reasons, at any time. If you draw on a canvas in response to a touch action, you have an updated canvas until the next refresh. If a refresh occurs the canvas repaints itself, you end up with a blank canvas.
I have no idea what your end goal is, but you likely want to either keep track of what the user has done and store that state somewhere and show it in a canvas on the repaint of the canvas. This could be done with storing all the actions and "replaying" them on the canvas, or simply storing the view of the canvas as a bitmap and reload the canvas with that bitmap when refreshed. But, in the later case I think using a canvas isn't the right solution.