I'm working on a Silverlight application and I have a hard time setting the relative path of an image in my application.
This is a brief picture of my project directory:
MyProject
L images
L mountain1.jpg
L SpriteObjects
L MountainFactory.cs
L GameScreen.xaml
Originally, I painted an Rectangle using an image brush from the GameScreen.xaml.
<Rectangle Name="rec_bg" HorizontalAlignment="Left" VerticalAlignment="Top" Width="800" Height="600">
<Rectangle.Fill>
<ImageBrush x:Name="ib_bg" ImageSource="./images/mountain1.jpg" ></ImageBrush>
</Rectangle.Fill>
</Rectangle>
This xaml code works, that is it can find the image in the images folder without any problem.
I want to change the image dynamically, and I created a class called MountainFactory.cs. In this class, I have a method with this code:
ImageBrush brush = new ImageBrush();
BitmapImage image = new BitmapImage(new Uri("./images/mountain" + level + ".jpg", UriKind.Relative));
brush.ImageSource = image;
This method will return an image brush which is applied to the rec_bg Rectangle object.
However, this code cannot find the specified image.
Does anyone who know how to fix this?
Thanks.
It depends on how you are embedded the image. I'm assuming you have it set as "Content" so it's not embedded in the DLL but does embed in the XAP. In that case, you simply access it relative to the project root, so you would be using:
"images/mountain..."
(Note, you don't use the ./ in front of it, you are automatically relative to the root of the application). If you have it set as an embedded resource, you'll need to extract it out of the DLL using a stream - I don't recommend that.
Short story boring: try removing the leading ./ and make sure the properties of the Image have it as Content.
Related
I am trying to place a collection of images at certain places on a canvas through Binding.
For some reason, the images are displaying but are NOT at the locations which I have specified.
C#
_roomView.Room = new Room
{
Items = new List<Item> {
new Item {ImageUri = "/Escape;component/Images/Items/a.jpg", XPosition = 190, YPosition = 50},
new Item {ImageUri = "/Escape;component/Images/Items/b.png", XPosition = 390, YPosition = 100},
new Item {ImageUri = "/Escape;component/Images/Items/b.png", XPosition = 490, YPosition = 600}}
};
listBoxItems.ItemsSource = _roomView.Room.Items;
XML
<Canvas>
<Image Source="{Binding ImageUri}" Stretch="None" Canvas.Left="{Binding Room.Items.XPosition}" Canvas.Top="{Binding Room.Items.YPosition}"/>
</Canvas>
XPosition and YPosition are of type int. I have tried changing them to double but the images still aren't being displayed where I want them to be. They only get displayed at the top left of the screen - on top of each other.
Can anyone see the problem?
You're using the pack URI format which is only valid if your images have a Build Action of "Embedded Resource". Even then, I'm not sure this URI format is actually supported for Image.Source and if the URI has to be Relative or Absolute. Check the images Build Action (Right click --> Properties on those files) and try changing the UriKind.
Either way, unless you have a very good reason it's best to keep media assets as:
Build Action = Content and use the normal path URIs. Adding images to DLLs as Embedded Resources is bad for startup performance since it takes longer to load your bigger DLLs into the AppDomain.
It's also bad from a memory usage perspective since the DLLs loaded into memory are now bigger.
Bottom line:
<Image Source="myPicture.png" /> format is much better for performance than
<Image Source="myAssemblyName;component/myPicture.png" /> syntax.
Your C# code has collection of images.
Your XAML only shows a single image. If the XAML is in the listbox data template, you'll get several canvases, with 1 image each.
To display a collection of images on the single Canvas, you could use e.g. <ItemsControl>, set ItemsPanel to a Canvas, and in the data template you specify a single image with source, canvas.left and canvas.top.
If you're trying to do what I've described with a ListBox instead of ItemsControl, it wont work because it has one more layer of UI elements between ItemsPanel and item, namely the item container.
P.S. Fastest way to troubleshoot such GUI problems - XAML Spy, I've bought myself a personal license. Evaluation is 21 days long, fully functional.
I have a image control in WPF. I need to reduce the image size control width and height. But when i Do that , the image is not looking good. The data loss is more.
So i thought to reduce the image resolution instead of just changing the image control width and height.
can any one help me how to change the image resolution of the binded image in WPF image control
[I mean image is already binded to image control now I have to the change the resolution only]
In .NET 4 they changed the default image scaling to a low quality one...so you can use BitmapScalingMode to switch back to the higher quality one:
<Image RenderOptions.BitmapScalingMode="HighQuality"
Source="myimage.png"
Width="100"
Height="100" />
http://10rem.net/blog/2010/05/01/crappy-image-resizing-in-wpf-try-renderoptionsbitmapscalingmode
You can also combine the above with other options like the Decode options if your source image is a huge image (this just reduces memory usage in your application).
http://www.shujaat.net/2010/08/wpf-saving-application-memory-by.html
other options to prevent "blurryness" is to put UseLayoutRounding="True" on your root element (i.e. Window)....it's recommended to use this in .NET 4 rather than SnapToDevicePixels:
When should I use SnapsToDevicePixels in WPF 4.0?
http://blogs.msdn.com/b/text/archive/2009/08/27/layout-rounding.aspx
You can use the DecodePixelWidth property like this:
<Image Stretch="Fill">
<Image.Source>
<BitmapImage CacheOption="OnLoad" DecodePixelWidth="2500" UriSource="Images/image.jpg"/>
</Image.Source>
</Image>
1) Have a try with a ViewBox : put your image within a ViewBox.
2) Sometimes the rendering engine looses quality because of pixel alignement issues, especially on low-resolution device. Have a look to SnapsToDevicePixels property, and try to set it to true in the containing control AND / OR in the ViewBox.
3) Obviously you could write a Control that perform a resolution change but it is quite some work.
Try this.
Image img = new Image();
var buffer = System.IO.File.ReadAllBytes(_filePath);
MemoryStream ms = new MemoryStream(buffer);
BitmapImage src = new BitmapImage();
src.BeginInit();
src.StreamSource = ms;
src.DecodePixelHeight = 200;//Your wanted image height
src.DecodePixelWidth = 300; //Your wanted image width
src.EndInit();
img.Source = src;
I'm having a strange issue with saving a UserControl as a JPG. Basically what I want to do is create a Live Tile that I can update using a Background Agent (as well as from within the app itself.)
I've followed the steps in this blog post which work great for when I create the tile; I have a custom UserControl with some TextBlocks on it which gets saved as a JPG into IsolatedStorage, exactly as the post says.
Creating the tile is no problem - the UserControl is rendered nicely as it should be. However, when I try to update the tile (using the exact same method - saving a new control as a JPG, then using that JPG as the BackgroundImage), things break down.
The resulting image that gets placed on the tile (and saved in IsolatedStorage) looks like this: squished tile (pulled from IsolatedStorage using the Isolated Storage Explorer Tool)
The background is black, and all the text runs down the side of the image (and overlaps each other) - the expected result is the background being the phone's accent colour, and the text appearing horizontal near the top.
The code used to generate and save the image is exactly the same in both instances - I've abstracted it out into a static method that returns StandardTileData. The only difference is where it is called from: in the working case where the tile is created, it's called from a page within the main app; in the non-working case (where the tile is updated), it's called from a page that can only be accessed by deep-linking from the tile itself.
Any thoughts? I'm guessing something's going wrong with the rendering of the Control to a JPG, since the actual image comes out this way.
The snippet of code that generates the image is here:
StandardTileData tileData = new StandardTileData();
// Create the Control that we'll render into an image.
TileImage image = new TileImage(textA, textB);
image.Measure(new Size(173, 173));
image.Arrange(new Rect(0, 0, 173, 173));
// Render and save it as a JPG.
WriteableBitmap bitmap = new WriteableBitmap(173, 173);
bitmap.Render(image, null);
bitmap.Invalidate();
IsolatedStorageFile storage = IsolatedStorageFile.GetUserStoreForApplication();
String imageFileName = "/Shared/ShellContent/tile" + locName + ".jpg";
using (IsolatedStorageFileStream stream = storage.CreateFile(imageFileName))
{
bitmap.SaveJpeg(stream, 173, 173, 0, 100);
}
tileData.BackgroundImage = new Uri("isostore:" + imageFileName, UriKind.Absolute);
return tileData;
The XAML for the control I'm trying to convert is here:
<UserControl x:Class="Fourcast.TileImage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
FontFamily="{StaticResource PhoneFontFamilyNormal}"
FontSize="{StaticResource PhoneFontSizeNormal}"
Foreground="{StaticResource PhoneForegroundBrush}"
d:DesignHeight="173" d:DesignWidth="173" FontStretch="Normal" Height="173" Width="173">
<Border Background="{StaticResource PhoneAccentBrush}">
<StackPanel>
<TextBlock HorizontalAlignment="Stretch"
TextWrapping="Wrap" VerticalAlignment="Stretch" Style="{StaticResource PhoneTextLargeStyle}" x:Name="Temperature"></TextBlock>
<TextBlock x:Name="Condition" HorizontalAlignment="Stretch"
TextWrapping="Wrap" VerticalAlignment="Stretch" Style="{StaticResource PhoneTextNormalStyle}">
</TextBlock>
</StackPanel>
</Border>
</UserControl>
Update: after some investigation with the debugger, it appears the calls to Measure and Arrange don't seem to do anything when the method is called from the class that's updating the tile. When the tile is being created, however, these calls function as expected (the ActualWidth and ActualHeight of the control get changed to 173).
Not sure what exactly is going on here, but here's what I ended up doing to workaround the issue.
I switched from trying to render a Control to defining a StackPanel in code, adding elements to it, then rendering that to an image. Oddly enough, though, the Arrange and Measure methods don't do anything unless another element has had them applied to it, and UpdateLayout called.
The full resulting code (minus the contents of the TextBlocks and writing to an image) is below.
StandardTileData tileData = new
// None of this actually does anything, but for some reason the StackPanel
// won't render properly without it.
Border image = new Border();
image.Measure(new Size(173, 173));
image.Arrange(new Rect(0, 0, 173, 173));
image.UpdateLayout();
// End of function-less code.
StackPanel stpContent = new StackPanel();
TextBlock txbTemperature = new TextBlock();
txbTemperature.Text = temperature;
txbTemperature.Style = (Style)Application.Current.Resources["PhoneTextLargeStyle"];
stpContent.Children.Add(txbTemperature);
TextBlock txbCondition = new TextBlock();
txbCondition.Text = condition;
txbCondition.Style = (Style)Application.Current.Resources["PhoneTextNormalStyle"];
stpContent.Children.Add(txbCondition);
stpContent.Measure(new Size(173, 173));
stpContent.Arrange(new Rect(0, 0, 173, 173));
The way to get the background of the image to use the phone's accent color is to make it transparent. This will require that you save a PNG rather than a JPG.
The ouput image looks like everything is wrapping more thna it needs to. You probably need to adjust the widths of the elements you're including in your control. Without the XAML it's hard to be more specific.
I also get this strange behaviour - squished tile (using Ree7 Tile toolkit),
Try call update tile into Dispatcher:
Deployment.Current.Dispatcher.BeginInvoke(() =>
{
CustomTile tile = GetTile(card);
StandardTileData tileData = tile.GetShellTileData();
shellTile.Update(tileData);
});
Working for me
I'm loading an image in WPF by using the BitmapImage class. My code works perfectly when I give an absolute path for the UriSource but not when I try and use a relative path.
My XAML is:
<Image Width="50" Name="MemberImage" HorizontalAlignment="Left">
<Image.Source>
<BitmapImage DecodePixelWidth="50" UriSource="questionmark.jpg" />
</Image.Source>
</Image>
The questionmark.jpg is added to the project with a Build Action of Resource and Copy to Output Directory set to Copy always. The error I get is "The file [file name] is not part of the project or its 'Build Action' property is not set to 'Resource'". This works when I use an absolute path for the UriSource but that obviously won't do.
How should I be defining my UriSource in the XAML?
I don't think you need to copy the image to output directory once it's in resource.
Correct way to specify is
<BitmapImage
x:Key = "Logo"
UriSource = "pack://application:,,,/ApplicationNamespace;component/Images/App/image.png"
/>
Just replace
ApplicationNamespace with your application namespace
and
Images/App/image.png with your image path in the project
Image files with the following options in properties
Build Action=Content
Copy to Output Directory=Copy if newer
<BitmapImage x:Key="QuestionMark" UriSource="pack://siteoforigin:,,,/questionmark.png"/>
Reference:
Xaml - Bitmap UriSource - absolute path works, relative path does not, why?
I cannot reproduce the problem on my computer:
I add the jpg by choosing Add existing item in the Project menu
I then set its Build Actio to Resource and Copy to Output directory to always.
My XAML is the same.
Works perfectly here, even after moving the .exe and renaming the jpg. Something else must be biting you!
This should be simple, but...
I created a folder in my solution called Images. I dragged an image into it. How do I now display this image on a Page or View?
Make sure the image is set as a Resource. It can be in any folder in any of your projects in your solution.
You can then reference this as [assembly];component/[path]/[imagename.extension]
For example:
<Image Source="/mynamespace.myassembly;component/ResourcesFolder/image.png" Width="16" Height="16" />
There are a couple of ways to get at it--here's the way that involves setting the image as a Resource in the Visual Studio file properties:
using (var stream = Application.GetResourceStream(
new Uri("SilverlightAssemblyName;component/Images/myImage.png",
UriKind.Relative)))
{
// read from stream
}
Where SilverlightAssemblyName is replaced by the Assembly Name you specified in the Silverlight tab of your Silverlight project.
If you want to use the image in code:
var bitmap = new BitmapImage();
bitmap.SetSource(stream);
myImageControl.ImageSource = bitmap;
Or, if you want to use the resource in XAML, you don't need any of the code:
<Image Source="/Images/myImage.png" Width="16" Height="16" />