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How to set boundary of a TextBlock in a grid?

I have few textblocks in a grid which can be dragged. I want to restrict the user so that user can't drag a textblock outside the grid.
I've tried a few ways like getting the position of the grid so that somehow i can control but it didn't work as expected.
Thanks in advance.

This can be done pretty easily using a Canvas inside the Grid, calculating the coordinates of the TextBlock inside of the Canvas and then continuously checking whether the TextBlock is still within its bounds. When the TextBlock leaves its bounds, the Transform then reverts back to it's last known 'good' coordinates.
XAML
<Grid>
<Grid Name="GridBounds" Width="600" Height="600" Background="Aqua">
<Canvas>
<TextBlock Name="TextBlock1" Text="Drag Me" FontSize="40" ManipulationDelta="TextBlock1_ManipulationDelta" ManipulationMode="TranslateX, TranslateY" HorizontalAlignment="Stretch" Canvas.Left="216" Canvas.Top="234" VerticalAlignment="Stretch"/>
</Canvas>
</Grid>
</Grid>
Code Behind
CompositeTransform TextDrag = new CompositeTransform();
CompositeTransform savedTransform = new CompositeTransform();
public MainPage()
{
this.InitializeComponent();
TextBlock1.RenderTransform = TextDrag;
}
// Copy Transform X and Y if TextBlock is within bounds
private void CopyTransform(CompositeTransform orig, CompositeTransform copy)
{
copy.TranslateX = orig.TranslateX;
copy.TranslateY = orig.TranslateY;
}
private void TextBlock1_ManipulationDelta(object sender, ManipulationDeltaRoutedEventArgs e)
{
TextDrag.TranslateX += e.Delta.Translation.X;
TextDrag.TranslateY += e.Delta.Translation.Y;
CompositeTransform transform = TextBlock1.RenderTransform as CompositeTransform;
// Get current Top-Left coordinates of TextBlock
var TextTopLeft = TextBlock1.TransformToVisual(GridBounds).TransformPoint(new Point(0, 0));
// Get current Bottom-Right coordinates of TextBlock
var TextBottomRight = TextBlock1.TransformToVisual(GridBounds).TransformPoint(new Point(TextBlock1.ActualWidth, TextBlock1.ActualHeight));
// Get Top-Left grid coordinates
var GridTopLeft = (new Point(0, 0));
// Get Bottom-Right grid coordinates
var GridBottomRight = (new Point(GridBounds.ActualWidth, GridBounds.ActualHeight));
if (TextTopLeft.X < GridTopLeft.X || TextBottomRight.X > GridBottomRight.X)
{
// Out of bounds on X axis - Revert to copied X transform
TextDrag.TranslateX = savedTransform.TranslateX; ;
}
else if (TextTopLeft.Y < GridTopLeft.Y || TextBottomRight.Y > GridBottomRight.Y)
{
// Out of bounds on Y axis - Revert to copied Y transform
TextDrag.TranslateY = savedTransform.TranslateY;
}
else
{
// TextBlock is within bounds - Copy X and Y Transform
CopyTransform(transform, savedTransform);
}
}
Here it is in action.

Scaling InkStrokes in UWP

I've got a simple demo application that uses an image as the background of an InkCanvas and I scale the strokes when the display of the image is resized so that they remain in the same place relative to the image. Since you can draw -> resize -> draw -> resize -> draw this means I have to scale each stroke a different amount each time by assigning the PointTransform on each stroke.
float thisScale = (float)(scale / _prevScale);
foreach (InkStroke stroke in myCanvas.InkPresenter.StrokeContainer.GetStrokes())
{
float thisPointScale = thisScale * stroke.PointTransform.M11;
stroke.PointTransform = Matrix3x2.CreateScale(new Vector2(thisPointScale));
}
This resizes the length of the strokes perfectly well. However, it does nothing to the thickness of the strokes. This is even more evident when you use a thick or non-uniform pen (eg the highlighter pen).
These link to two screen clips which show the results.
Full-screen - https://1drv.ms/i/s!ArHMZAt1svlBiZZDfrxFqyGU1bJ6MQ
Smaller window - https://1drv.ms/i/s!ArHMZAt1svlBiZZCqHHYaISPfWMMpQ
Any ideas on how I can resize the thickness of the strokes?

Apply a ScaleTransform to the InkCanvas control. That'll take care of scaling the ink stroke,the stroke locations and the background image. Essentially the transform applies to everything contained in the InkCanvas. No need to use the Matrix with the StrokeCollection.
XAML
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="1*" />
</Grid.RowDefinitions>
<StackPanel Orientation="Horizontal">
<Button Content="Red Highlighter "
x:Name="InkRedAttributesButton"
Click="InkRedAttributesButton_Click" />
<Button Content="Blue Highlighter "
x:Name="InkBlueAttributesButton"
Click="InkBlueAttributesButton_Click" />
<Button Content="Scale Down"
x:Name="ScaleDownButton"
Click="ScaleDownButton_Click" />
<Button Content="Scale Up"
x:Name="ScaleUpButton"
Click="ScaleUpButton_Click" />
</StackPanel>
<InkCanvas x:Name="myCanvas"
Grid.Row="1" HorizontalAlignment="Left" VerticalAlignment="Top">
<InkCanvas.Background>
<ImageBrush ImageSource="/SO_Questions;component/Images/Star02.jpg"
Stretch="Fill" />
</InkCanvas.Background>
<InkCanvas.RenderTransform>
<ScaleTransform x:Name="InkCanvasScaleTransform" />
</InkCanvas.RenderTransform>
</InkCanvas>
</Grid>
Code
private void ScaleUpButton_Click(object sender, RoutedEventArgs e) {
InkCanvasScaleTransform.ScaleX += .2;
InkCanvasScaleTransform.ScaleY += .2;
}
private void ScaleDownButton_Click(object sender, RoutedEventArgs e) {
InkCanvasScaleTransform.ScaleX -= .2;
InkCanvasScaleTransform.ScaleY -= .2;
}
private void InkRedAttributesButton_Click(object sender, RoutedEventArgs e) {
DrawingAttributes inkAttributes = new DrawingAttributes();
inkAttributes.Height = 12;
inkAttributes.Width = 12;
inkAttributes.Color = Colors.Red;
inkAttributes.IsHighlighter = true;
myCanvas.DefaultDrawingAttributes = inkAttributes;
}
private void InkBlueAttributesButton_Click(object sender, RoutedEventArgs e) {
DrawingAttributes inkAttributes = new DrawingAttributes();
inkAttributes.Height = 12;
inkAttributes.Width = 12;
inkAttributes.Color = Colors.Blue;
inkAttributes.IsHighlighter = true;
myCanvas.DefaultDrawingAttributes = inkAttributes;
}
Screenshots
Scaled 100%
Scaled 60%

Scaling the InkCanvas doesn't always fix the problem especially if you are wanting to save the scaled ink into a gif image file.
Apparently an InkStroke's PointTransform only transforms the location of the stroke's points, but not the size of the PenTip used to draw the stroke. (Not documented anywhere that I can find, but discovered by trial and error. The name 'PointTransform' is a bit of a clue)
So as well as applying your scaling factor to the PointTransform, you also have to scale the PenTip as follows (modification to your original code):
float thisPointScale = thisScale * stroke.PointTransform.M11;
stroke.PointTransform = Matrix3x2.CreateScale(new Vector2(thisPointScale));
stroke.DrawingAttributes.PenTipTransform = Matrix3x2.CreateScale(new Vector2(thisPointScale));
Hope this helps someone...

To resize the thickness of the strokes you have to change the Size property of the DrawingAttributes. PenTipTransform doesn't work for pencil - it throws an exception.
The point is that you cannot set the DrawingAttributes property of the stroke directly: https://learn.microsoft.com/en-us/uwp/api/windows.ui.input.inking.inkdrawingattributes
Here is example how to get this:
static IEnumerable<InkStroke> GetScaledStrokes(IEnumerable<InkStroke> source, float scale)
{
var scaleMatrix = Matrix3x2.CreateScale(scale);
var resultStrokes = source.Select(x => x.Clone()).ToArray();
foreach (var inkStroke in resultStrokes)
{
inkStroke.PointTransform = scaleMatrix;
var da = inkStroke.DrawingAttributes;
var daSize = da.Size;
daSize.Width = daSize.Width * scale;
daSize.Height = daSize.Height * scale;
da.Size = daSize;
inkStroke.DrawingAttributes = da;
}
return resultStrokes;
}
Complete example: https://github.com/ycherkes/ScaledInks

Analog Clock, Rotate Hands C# WPF

I am working on a WPF project, trying to create an analog clock. I have an image of a clock (without the hands) and have set it as a background. I also have images of two hands of clock, which I want to rotate keeping one end fixed (like it happens in a clock). How can I rotate the image keeping its one end fixed in C#.NET (WPF)? What I have tried is the following code:
namespace AnalogWatch
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
DispatcherTimer dispatcherTimer;
private int degrees = 0;
public MainWindow()
{
InitializeComponent();
dispatcherTimer = new DispatcherTimer();
dispatcherTimer.Tick += new EventHandler(dispatcherTimer_Tick);
dispatcherTimer.Interval = new TimeSpan(0, 0, 1);
}
private void dispatcherTimer_Tick(object sender, EventArgs e)
{
degrees += 5;
if (degrees > 360)
{
degrees = 0;
}
RotateTransform transform = new RotateTransform(degrees,StickImg.Width/2,StickImg.Height/2);
//StickImg.RenderTransformOrigin = new System.Windows.Point(0, 0);
StickImg.RenderTransform = transform;
}
private void Window_ContentRendered_1(object sender, EventArgs e)
{
dispatcherTimer.Start();
}
}
}
It is rotating the image but not keeping its one end fixed. What is the problem here ?
XAML is:
<Window x:Class="AnalogWatch.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525" ContentRendered="Window_ContentRendered_1">
<Grid>
<Image x:Name="StickImg" HorizontalAlignment="Left" Height="100" VerticalAlignment="Top" Width="100" Margin="207,70,0,0" Source="stick.png"/>
</Grid>
</Window>

Updated.
Your code should work if clock hand exactly in the center of rectangular image.
Like this one
You can do either like you did
RotateTransform transform =new RotateTransform(degrees, StickImg.Width/2,StickImg.Height/2);
or
RotateTransform transform = new RotateTransform(degrees);
StickImg.RenderTransformOrigin = new Point(0.5, 0.5);

Use the RenderTransformOrigin of the element to set the center of rotation.
Note that the coordinates are scaled to 0..1
So to rotate around the center:
RenderTransformOrigin="0.5, 0.5"
Just make sure that the pivot of the hand is in the center of the element.

here's the code i'm using and it works like charm..as qwr suggested clock hand should be exactly in the center of rectangular image
c# code
DispatcherTimer clock = new DispatcherTimer();
public AnalogClock()
{
InitializeComponent();
clock.Interval =TimeSpan.FromMilliseconds(100);
clock.Tick += clock_Tick;
clock.Start();
}
void clock_Tick(object sender, EventArgs e)
{
double milsec = DateTime.Now.Millisecond;
double sec = DateTime.Now.Second;
double min = DateTime.Now.Minute;
double hr = DateTime.Now.Hour;
seconds.LayoutTransform = new RotateTransform(((sec / 60) * 360)+((milsec/1000)*6));
minutes.LayoutTransform = new RotateTransform((min * 360 / 60)+((sec/60)*6));
hours.LayoutTransform = new RotateTransform((hr * 360 / 12)+(min/2));
}
and the XAML code for images
<Grid Margin="-100">
<Image x:Name="clockface" RenderOptions.BitmapScalingMode="HighQuality" Source="images/panel.PNG" RenderTransformOrigin="0.5,0.5" HorizontalAlignment="Center" VerticalAlignment="Center" Height="194" Margin="100" Width="194"/>
<Image x:Name="hours" RenderOptions.BitmapScalingMode="HighQuality" Source="images/hours.PNG" RenderTransformOrigin="0.5,0.5" VerticalAlignment="Center" HorizontalAlignment="Center" Height="194" Margin="100" Width="194"/>
<Image x:Name="minutes" RenderOptions.BitmapScalingMode="HighQuality" Source="images/minutes.PNG" RenderTransformOrigin="0.5,0.5" VerticalAlignment="Center" HorizontalAlignment="Center" Height="194" Margin="100" Width="194"/>
<Image x:Name="seconds" RenderOptions.BitmapScalingMode="HighQuality" Source="images/seconds.PNG" RenderTransformOrigin="0.5,0.5" HorizontalAlignment="Center" VerticalAlignment="Center" Height="194" Margin="100" Width="194"/>
</Grid>
note the i've used the code in a separate usercontrol..
just make sure that the margin between the clock hand image and the grid i'ts contained in should be enough to make room for the image to rotate else it will displace while rotating..
hope this helps..!

Rotate image while key down, in WPF

I have an image that is inside a popup. When I am inside the canvas, and if a key is down I want to rotate the popup. My code doesnt update the rotation unless I leave the canvas (move mouse outside of canvas), then enter again (move mouse inside canvas). I confirmed the angle is being updated when the key is down inside the canvas, so I have no clue why it doesnt update unless I exit and reenter.
<Popup Name="floatingTip"
AllowsTransparency="True"
Placement="Relative"
PlacementTarget="{Binding ElementName=MainCanvas}">
<Popup.RenderTransform>
<RotateTransform CenterX="1" CenterY="1" Angle="{Binding Angle}"/>
</Popup.RenderTransform>
<Image Source="{Binding Name}"
Width="{Binding Width}"
Height="{Binding Height}"/>
</Popup>
When the mouse enters the canvas space, I set CanvasIsActive = true.
Here is the KeyDown event:
private void Window_KeyDown(object sender, KeyEventArgs e)
{
if (CanvasIsActive && currentTool == "staticBrush")
{
cursorImage.Angle += 20;
this.Title = cursorImage.Angle.ToString();
}
}
Here is my Angle property that is updated when a key is down:
double imgAngle;
public double Angle
{
get { return imgAngle; }
set
{
imgAngle = value;
OnPropertyChanged("Angle");
}
}

I figured it out. To refresh the rotation inside the popup, the popup IsOpen needs to be set to false, then back to true. Another solution is to move the RotateTransform from the Popup to the Image.

Rotating a border doesn't change window size

I try to rotate a Border and have the MainWindow change his size based on the new space taken by the Border rotation.
I've set SizeToContent="WidthAndHeight" but window size does't take change when I rotated the border.
Do I need to programmatically set the Width and Height for the MainWindow or this can be achieved changing the xaml code in some other way?
My xaml code:
<Window x:Class="MyClass.MainWindow"
WindowStyle="None" AllowsTransparency='True'
Topmost='False' Background="Transparent" ShowInTaskbar='False'
SizeToContent="WidthAndHeight" WindowStartupLocation="Manual">
<Border Name="MyBorder"
BorderBrush="Transparent"
Background="Transparent"
HorizontalAlignment="Left"
VerticalAlignment="Top"
RenderTransformOrigin="0.5,0.5">
</Border>
</Windows>
My c# code on Window_KeyDown:
# RotateTransform rt = new RotateTransform() is declared at class level.
if (e.Key == Key.I)
{
if (rt.Angle + 1 < 360)
{
rt.Angle += 1;
}
else
{
rt.Angle = 0;
}
MyBorder.RenderTransform = rt;
}

Use LayoutTransform instead of RenderTransform
From MSDN: Transforms Overview
LayoutTransform – A transform that is applied before the layout pass. After the transform is applied, the layout system processes the
transformed size and position of the element.
RenderTransform – A transform that modifies the appearance of the element but is applied after the layout pass is complete. By using the
RenderTransform property instead of the LayoutTransform property, you
can obtain performance benefits.
Example
<Border Name="MyBorder"
BorderBrush="Transparent"
Background="Transparent"
HorizontalAlignment="Left"
VerticalAlignment="Top"
RenderTransformOrigin="0.5,0.5">
<Border.LayoutTransform>
<RotateTransform Angle="90"/>
</Border.LayoutTransform>
</Border>
So in your case
RotateTransform rt = new RotateTransform(0.0, 0.5, 0.5);
private void Window_KeyDown(object sender, KeyEventArgs e)
{
if (e.Key == Key.I)
{
if (rt.Angle + 1 < 360)
{
rt.Angle += 1;
}
else
{
rt.Angle = 0;
}
MyBorder.LayoutTransform = rt;
}
}}