I have this peculiar problem. I am having a user control . I am making an app for Windows 8.1 where I would choose an image from my Picture gallery. The image would open in my app with Stretch is Uniform and Horizontal And vertical alignment to center.
My user control will appear where I tap on the image. Now the problem is , when the image Stretch was none , I was able to magnify the correct region (around my click) , but now when I make it Stretch to Uniform and Set the horizontal and vertical Alignment to Center , I am getting other pixel information in my user control.
I want to know how to fix it.Any how , the images can be of 2*Full HD also or they can be HD or even less. Secondly , I want to know the boundaries of the image . With boundaries I want to say that , my user control shouldnt go above the boundaries of the image . How to implement that. If my code is needed , I would paste it , If required.
Have this video for reference . This is what I have to develop ! I have the user control ready and I am getting exact pixels for Stretch=NONE , and no Horizontal And Vertical Alignment set.
This is my code for my app
I believe the issue is with how you use the control, rather than the image. If you avoid doing the bitmap cropping and replacing, it would speed up dramatically and likely work for all stretch types.
I've modified the source to show this - removing the Cropping completely. If you need cropping for other reasons, you should consider using the unsafe keyword (and property setting to allow) in order to dramatically speed up its use.
Also, to avoid the lagging/jumping upward, I added IsHitTestVisible="False" so that your delta wouldn't be interrupted by hovering over your image.
I see you have the 45-degree code already - since it wasn't in your source, I only added an example of 90 degree rotation when you get to the sides - so you can see how to set a RenderTransformOrigin point.
MainPage.xaml:
<Page x:Name="page1"
x:Class="controlMagnifier.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:controlMagnifier"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">
<Grid x:Name="ParentGrid" Background="{ThemeResource ApplicationPageBackgroundThemeBrush}" PointerReleased="ParentGrid_OnPointerReleased" >
<Canvas x:Name="InkPresenter" Height="auto" Width="auto">
<Image Stretch="Uniform" x:Name="image2" >
<Image.Source >
<BitmapImage UriSource="/Assets/wallpaper.jpg" />
</Image.Source>
</Image>
</Canvas>
<local:MagnifierUsercontrol x:Name="MagnifyTip" Visibility="Collapsed" ManipulationMode="All"
IsHitTestVisible="False" Height="227" Width="171"
VerticalContentAlignment="Bottom" HorizontalContentAlignment="Center">
</local:MagnifierUsercontrol>
</Grid>
</Page>
MainPage.xaml.cs:
using System;
using Windows.Foundation;
using Windows.Storage;
using Windows.UI.Input;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Media.Imaging;
namespace controlMagnifier
{
public sealed partial class MainPage : Page
{
public const int XAxis = 200;
public const int YAxis = 435;
private readonly RotateTransform myRotateTransform = new RotateTransform {CenterX = 0.5, CenterY = 1};
private readonly ScaleTransform myScaleTransform = new ScaleTransform {ScaleX = 1, ScaleY = 1};
private readonly TransformGroup myTransformGroup = new TransformGroup();
private readonly TranslateTransform myTranslateTransform = new TranslateTransform();
public WriteableBitmap CurrentBitmapObj, CurrentCroppedImage = null;
public Point currentContactPt, GridPoint;
public Thickness margin;
public PointerPoint pt;
public double xValue, yValue;
public MainPage()
{
InitializeComponent();
ParentGrid.Holding += Grid_Holding;
image2.PointerMoved += InkCanvas_PointerMoved;
image2.PointerReleased += ParentGrid_OnPointerReleased;
margin = MagnifyTip.Margin;
image2.CacheMode = new BitmapCache();
myTransformGroup.Children.Add(myScaleTransform);
myTransformGroup.Children.Add(myRotateTransform);
myTransformGroup.Children.Add(myTranslateTransform);
MagnifyTip.RenderTransformOrigin = new Point(0.5, 1);
MagnifyTip.RenderTransform = myTransformGroup;
}
private void Grid_Holding(object sender, HoldingRoutedEventArgs e)
{
try
{
GridPoint = e.GetPosition(image2);
myTranslateTransform.X = xValue - XAxis;
myTranslateTransform.Y = yValue - YAxis;
MagnifyTip.RenderTransform = myTransformGroup;
MagnifyTip.Visibility = Visibility.Visible;
}
catch (Exception)
{
throw;
}
}
private void InkCanvas_PointerMoved(object sender, PointerRoutedEventArgs e)
{
try
{
pt = e.GetCurrentPoint(image2);
currentContactPt = pt.Position;
xValue = currentContactPt.X;
yValue = currentContactPt.Y;
if (xValue > 300)
{
myRotateTransform.Angle = -90;
}
else if (xValue < 100)
{
myRotateTransform.Angle = 90;
}
else
{
myRotateTransform.Angle = 0;
}
MagnifyTip.RenderTransform = myRotateTransform;
myTranslateTransform.X = xValue - XAxis;
myTranslateTransform.Y = yValue - YAxis;
MagnifyTip.RenderTransform = myTransformGroup;
}
catch (Exception)
{
throw;
}
finally
{
e.Handled = true;
}
}
private async void StoreCrrentImage()
{
try
{
var storageFile =
await
StorageFile.GetFileFromApplicationUriAsync(new Uri("ms-appx:///Assets/wallpaper.jpg",
UriKind.RelativeOrAbsolute));
using (
var fileStream =
await storageFile.OpenAsync(FileAccessMode.Read))
{
var bitmapImage = new BitmapImage();
await bitmapImage.SetSourceAsync(fileStream);
var writeableBitmap =
new WriteableBitmap(bitmapImage.PixelWidth, bitmapImage.PixelHeight);
fileStream.Seek(0);
await writeableBitmap.SetSourceAsync(fileStream);
CurrentBitmapObj = writeableBitmap;
writeableBitmap.Invalidate();
}
}
catch (Exception)
{
// Graphics g=new Graphics();
throw;
}
finally
{
}
}
private void ParentGrid_OnPointerReleased(object sender, PointerRoutedEventArgs e)
{
MagnifyTip.Visibility = Visibility.Collapsed;
}
}
}
MagnifierUsercontrol.xaml:
<UserControl
x:Class="controlMagnifier.MagnifierUsercontrol"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:controlMagnifier"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d" Height="227" Width="171">
<Canvas x:Name="controlCanvas" x:FieldModifier="public" Height="Auto" Width="Auto" >
<Grid Height="227" Width="171" HorizontalAlignment="Center" Canvas.Left="0" Canvas.Top="0">
<Border x:FieldModifier="public" x:Name="imgBorder" Width="150" CornerRadius="50,50,50,50" Margin="13,25,13,97">
<Border.Background>
<ImageBrush x:FieldModifier="public" x:Name="image1" />
</Border.Background>
</Border>
<TextBlock x:Name="txtreading" Height="30" Width="80" Margin="0,-145,0,0" FontWeight="Bold" Foreground="Red" FontSize="20" Text="ABC" TextAlignment="Center" />
<!--<Image Height="120" Width="150" Margin="0,-50,0,0" Source="Assets/SmallLogo.scale-100.png" ></Image>-->
<Path x:Name="MagnifyTip" Data="M25.533,0C15.457,0,7.262,8.199,7.262,18.271c0,9.461,13.676,19.698,17.63,32.338 c0.085,0.273,0.34,0.459,0.626,0.457c0.287-0.004,0.538-0.192,0.619-0.467c3.836-12.951,17.666-22.856,17.667-32.33 C43.803,8.199,35.607,0,25.533,0z M25.533,32.131c-7.9,0-14.328-6.429-14.328-14.328c0-7.9,6.428-14.328,14.328-14.328 c7.898,0,14.327,6.428,14.327,14.328C39.86,25.702,33.431,32.131,25.533,32.131z" Fill="#FFF4F4F5" Stretch="Fill" Stroke="Black" UseLayoutRounding="False" Height="227" Width="171" />
</Grid>
</Canvas>
</UserControl>
Let me know if this helps or if there is further toward your specific question.