Develop Reference

Let user resize control (textbox, specifically) in Canvas UWP

I have a canvas with a button that the user can press to add a new textbox to the canvas. How can I make it so the user can resize the text box by clicking and dragging on any of the corners of the textbox. Because the textbox is created in the C# code (not XAML), I would prefer code in C# not XAML.
Thanks
EDIT: My question is different than the one referenced because it is in UWP not WPF. These have very different controls. I would appreciate if you could translate the UWP information into UWP C#

You can use Thumb control instead of a textbox. The thumb control provides the functionality for you to write code to customize the drag and drop behavior. A simple code would be:
<Canvas x:Name="test">
<Thumb Width="100" Height="100">
<Thumb.Template>
<ControlTemplate>
<TextBlock HorizontalAlignment="Center" Text="12345"/>
</ControlTemplate>
</Thumb.Template>
</Thumb>
</Canvas>
A more complex sample could be found from this SO thread from Jay's answer. But please notice you need to customize the logic yourself in order to make it resize like what you need. The reference is just a direction.

Most simple FrameworkElement to handle HorizontalAlignment and VerticalAlignment?

This is Silverlight.
Initial goal is to display a random element in a Popup with some VerticalAlignment and HorizontalAlignment. I do not want to use VerticalOffset or HorizontalOffset, because there is more to what I really want to do, including some complex bindings.
First attempt was:
<Popup>
<Button
Height="135"
HorizontalAlignment="Stretch"
VerticalAlignment="Bottom" />
</Popup>
Second attempt was:
<Popup
Height="135"
HorizontalAlignment="Stretch"
VerticalAlignment="Bottom">
<Button />
</Popup>
Both were a failure: the Button was always on Top and not Stretch (HorizontalAlignment and VerticalAlignment didn't work).
So I had the idea to encapsulate the element in a simple FrameworkElement:
<Popup>
<Border>
<Button
Height="135"
HorizontalAlignment="Stretch"
VerticalAlignment="Bottom" />
</Border>
</Popup>
And it is working.
But I had to use Border in this example, when I could have done it with Grid and many other FrameworkElement (but not with Canvas or Viewbox or Popup). I'd like to know what is the most simple, efficient and processor-friendly transparent FrameworkElement to encapsulate another element with working HorizontalAlignment and VerticalAlignment? Is it:
Border? (like the above example)
UserControl?
ContentControl?
ContentContainer?
some custom and basic MyFrameworkElement? (might need help for most basic implementation)
something else like Grid?

WPF controls come in two flavors: Ones that interact with users (like accept user clicks like a button, or display text like a text block) and containers that control placement and layout of the previous ones.
Container controls are usually designed to lay out their children in a specific manner. For example, Canvases lay out children by X, Y, Width & Height values. Each one has a specific use, so you must read the documentation or tutorials for these container controls and understand how each works in order to select the appropriate one for a task.
In your case, you want the button to fill all available space in the popup (it seems, it isn't that clear). I know that the Grid does this by default. So I would do the following:
<Popup><Grid><Button /></Grid></Popup>

Adding elements to a panel in c#!

quick question, in a c# Windows Presentation Foundation How can i add some elements to a Panel so i can easily hide all the elements (Text, Labels...) by just hiding the panel it self?
I have already tried to just put panels over the elements to hide them but i don't think that would be a neat solution because i would also hide all the other elements under it.
I need this because i am trying to have different forms in the same place and on the base of what the user types the items should appear. I don't want it to open a new window.
Thanks!

Assuming all your elements are in the same container, just set the Visibility property of the container to "Collapsed". Ideally, this would be by binding to a bool and using the BoolToVisibility converter provided in WPF.
If they are NOT in the same container, you are a bit out of luck. You will need to set/bind each of the element's visibility properties separately, but using the same techniques as above.

If you place all of the elements you want on that panel you can tell that panel to be invisible or visible and all of the elements on that panel will hide or show accordingly. For ease of use when you are programming you can right click on the panel and choose send back or bring forward and this will help you navigate your form while programming.

Panel is a base class and has a Visibility property
Panel Properties
<StackPanel x:Name="pnl1" Grid.Row=0 Visibility="Collapsed">
<TextBlock x:Name="tbTime" />
<TextBlock x:Name="tbDate" />
</StackPanel>
<StackPanel x:Name="pnl2" Grid.Row=2 Visibility="Visible">
<TextBlock x:Name="tbTime2" />
<TextBlock x:Name="tbDate2" />
</StackPanel>

Change StackPanel location on a Canvas programmatically

I have stackpanel in a canvas
The stackpanel has
<Canvas x:Name="MyCanvas">
<Slider Template="{StaticResource simpleSlider}" x:Name="seekBar" Thumb.DragStarted="seekBar_DragStarted" Thumb.DragCompleted="seekBar_DragCompleted" Canvas.Left="347" Canvas.Top="746" Width="900" Height="2" />
<Rectangle Height="5" />
<StackPanel Canvas.Left="200" Canvas.Right = "100">
</StackPanel>
</Canvas>
At runtime I need to change the location of the objects within the StackPanel.
Ie seekBar.Canvas.Left = 50

The "Canvas.Left" is an example of attached dependency property. The syntax for the C# is:
Canvas.SetLeft(myStackPanel, 50);
Where myStackPanel is any custom name you must assign using x.Name in the xaml.

You should use Canvas.SetLeft and Canvas.SetRight methods.

Caveat: I'm assuming that by this:
At runtime i need to change the location of the objects within the StackPanel.
You mean that you need to be able to set the Left position of the StackPanel itself (irrespective of what it contains). If this is not what you mean (for example, you don't have anything called seekBar in your example Xaml, even though you reference it in your code), please clarify.
The Canvas uses Attached Dependency Properties (as do other layout items, such as the Grid) to track layout information about contained items. Because of this, you'll either have to use the GetLeft and SetLeft functions on Canvas, GetValue and SetValue functions on your StackPanel to manipulate these values.
Do this, you'll need to give your StackPanel a name. I'll call it stack.
Given your example, you would do either this:
Canvas.SetLeft(stack, 50);
or this:
stack.SetValue(Canvas.LeftProperty, 50);
Note that the first version (SetLeft) is simply a wrapper around the second version, so use whichever you prefer.

You can get the value of any control by var x = btn.TransformToAncestor(this).Transform(new Point(0, 0));
where btn is the control which you want the margin of.
And then use yourstackpanel.SetValue(StackPanel.MarginProperty,new Thickness());

Bing Maps (Silverlight) maps - specifying canvas to be at foreground through XAML

Below is the XAML code i have for a Bing Maps Silverlight weather related implementation.
Here is what i am trying to do:
Have a bing maps with several (over 100) pushpins- on mouseover - show a contentpopup (canvas=myPopup) below. Simple enough.
Everything works fine - however, when mypopup displays on mouseover, it is not on the foreground (the other pins appear on top of the contentpopup) - hence making it not very readable.
Question:
How do i specifiy the myPopup canvas specified in XAML below to always appear in the foreground, i.e. top most of the Bing Maps silverlight control when a user views it on mouseover.
Thanks!
<Grid x:Name="LayoutRoot" Background="White">
<m:Map x:Name="GlobalMap" Mode="Road" Center="15,7" ZoomLevel="2" CredentialsProvider="{StaticResource MyCredentials}" Margin="-70,-40,-100,-72">
<m:MapLayer x:Name="myLayer">
<Canvas x:Name="myPopup" Visibility="Collapsed" Opacity="1">
<Rectangle x:Name="myPopupRectangle" Fill="White" Canvas.Left="0" Canvas.Top="0" Height="100"
Width="100" RadiusX="15" RadiusY="15"/>
<StackPanel Canvas.Left="8" Canvas.Top="8">
<TextBlock x:Name="myPopupTexts" FontSize="5" Width="100">
</TextBlock>
</StackPanel>
</Canvas>
</m:MapLayer>
</m:Map>
</Grid>

Try adding Canvas.ZIndex to the MapLayer element, give it a large value like 200 or add your push pins to another MapLayer (rather than adding the pins directly to the map) that appears ahead of this popup layer in document order.

I did something similar to this, but took a different approach. What I did was create a custom pushpin template and create a PopUp within the template.
When the user hovers over the pushpin, the popup is displayed. Using the PopUp will solve your problem, since the control will automatically position it on top of everything. Try wrapping the Canvas in a PopPup and see if that works.
hth