I am working on windows phone application in which i need to change ApplicationBarButton icon dinamically, for example to show current date like in default Windows Phone Calendar app. Regarding to this article, we can use only png images previously added to solution and reference to them with relative Uri.
It is not a problem for me to generate correct png image (this way and using ToolStack C# PNG Writer Library) and save it to isolated storage, but when i'm initializing AppBarButton with absolute Uri to this image and trying to add it to ApplicationBar, my app throws ArgumentException.
Am i doing something wrong or i just have to draw 366 icons and add them to my project? :)
Thanks in advance!
Related
I'm trying to add a local image in my Xamarin app, but it's not working. Do you know what I could've have missed?
I have added the XAML and c# code but that still does not work.
XAML - <Image x:Name="Background_Image" Source="backgroundimage.png"/>
C# - var image = new Image { Source = "backgroundimage.png" };
I have followed the proper practices to a tee from the Xamarin Images documentation, but it's still not working. Link to Xamarin Documentation on Images - (https://learn.microsoft.com/en-us/xamarin/xamarin-forms/user-interface/images?tabs=vswin#Local_Images)
I have made sure the file name is
All in lowercase,
The build action is AndroidResource of the image
The image has been placed in the Resources/drawable folder.
Which are all the conventions you must follow, but it doesn't seem to work.
The image's file size is 1.28mb and resolution is 1920x1080 if that matters. I have tested with a much smaller 4KB image but does not work either.
I am using the Xamarin Live Player to show the app, the phone uses API 19, Android 4.4
I apologise if this is a duplicate, but I have read many topics here but I have not been able to fix it.
It does seem to be a issue or limitation with Xamarin's own Live player. I have launched the App with the Android Emulator and the Image is displaying, I'll report it as a bug.
In Android, it is quite easy to set a image placeholder for development purposes in an imageview.
All one would do is use the tools:src for the placeholder image during development so you could see it in your layout design preview and your actual image you would put into your android:src
. Frequently, you don't set the android:src put would populate that imageview with images that you download off the internet once you connect your app to the net:
<ImageView
android:layout_width="28dp"
android:layout_height="28dp"
android:src=#drawable/activated_icon"
tools:src="#mipmap/white_activated_icon" />
In Xamarin, you have this to display images:
<Image Source="http://lorempixel.com/1920/1080/nature/3" />
Once the app connects, the image is downloaded from the internet and displayed. How do I put in a placeholder image for development purposes (similar to the way you would do it through tools:src in android) so I can see it within the layout design previews?
I'm assuming you want to achieve this with Xamarin Forms, as you referring to XAML in the question title.
Or possibly you are referring to the Xamarin Forms Previewer? In that case, disregard the following answer. You can only use local images in the Previewer as far as I can tell.
Answer in case the question is related to runtime Xamarin Forms
There is no standard option to do this in Xamarin Forms. Take a look at this example suggested by Stephane Delcroix from the Xamarin Forums. The important part of this approach is to stack 2 images on top of each other in a grid. 1 is the placeholder that is placed beneath the image that is being loaded, like this:
var grid = new Grid();
grid.RowDefinitions.Add (new RowDefinition());
grid.Children.Add (image);
grid.Children.Add (placeholderImage);
As an alternative option, WebImage of Xamarin Forms Labs allows an option for a DefaultImage, but I'm not sure if that shows immediately. See this class for the code of the Web Image. Keep in mind that Xamarin Forms Labs is no longer under active maintenance.
Of course you can also write a custom renderer. Maybe based on the Xamarin Forms Labs example.
I use FFImageLoading for this Case.
Just install the Nuget Package and Use the "CachedImage" in XAML.
<ff:CachedImage Source="your url" Placeholder="placeholder while loading"/>
You don´t need to download (and cache) the Image manually then. It will automatically displayed when the download is done.
You can use local files (from Resources or Drawable) and files from HTTP/HTTPS.
I'm trying to write an application that offers toast notifications on Windows 8 and newer.
Is it possible instead of referencing an image file on the local disk to use data URIs in order to display an image via the XML that one passes to show the toast? I was unable to come up with any documentation so far and I am still in the research phase for my project (so no code to "simply" try, yet).
No. DataUris are not supported for images in toasts (or tiles)
Update/documentation/proof:
For 8
From https://msdn.microsoft.com/en-us/library/windows/apps/hh761494.aspx
In this set of templates, the image element is expressed using one of
these protocols:
•http:// or https:// A web-based image.
•ms-appx:/// An image included in the app package.
•ms-appdata:///local/ An image saved to local storage.
•file:/// A local image. (Only supported for desktop apps.)
And for 10
From https://msdn.microsoft.com/en-us/library/windows/apps/br230844.aspx
The URI of the image source, using one of these protocol handlers:
•http:// or https:// A web-based image.
•ms-appx:/// An image included in the app package.
•ms-appdata:///local/ An image saved to local storage.
•file:/// A local image. (Supported only for desktop apps. This protocol cannot be used by Windows Store apps.)
Bonus, on WP 8.X you couldn't even specify the image, it just used the app icon.
I'm trying to create live tiles in my app by using BitmapRender (in Windows 8.1) to create an image from a user control, which I then want to add as my live tile image.
Creating the image works perfectly, and I store it in the app's roaming folder. However, I can't get the image to add to the live tile when created this way. The odd thing is that if I copy my generated file into the project and then try to attach it to the live tile it works (so the image must be correctly formatted/size, etc.); and if I copy a random image into my roaming folder and set that as the live tile image it also works (meaning I am able to use a file in the roaming folder to set the tile image)...so that means I am referencing the file location correctly, and the image itself is capable of being used on a live tile...so why doesn't it work?
I have created a sample project (link below) that illustrates that my live tile creating code works (with an image stored in the project), and also that I can successfully create an image from a UI control and store it in the roaming folder (FWIW I've tried using different folders with no change in behaviour).
Is there something I'm missing? Any insight or help would be greatly appreciated.
Project is in VB.net, but I can figure out answers in C# if that's easier.
Sample project to illustrate the issue
The trouble is that you're attempting to use an absolute file path to reference the image, which is not supported. If you look in the tile schema, specifically at the page for the element, you'll see that the src must be an URI using http[s]://, ms-appx:///, or ms-appdata:///local for Windows Store apps. The fact that you can use a relative in-package path of /livetile.png is a bit of a fluke, as that's defaulting to ms-appx:///livetile.png.
What you need to do, then, is just use this for a filepath:
filepath = "ms-appdata:///local/livetile.png"
I tried this in your sample and it worked fine. Do note that only the local folder is supported here, not roaming. This is primarily because roaming appdata is limited to 100K to begin with, and dropping tile images in there would often quickly fill your quota. You'll want to then generate the image locally on each device (which would make sense also because you can then take the current scaling into account).
I want to use icons like opened/closed folder in my table (UITableView)?
UPD:
For example, in Java you can get a standard image "folder" and use it in the FileTree:
new
DefaultTreeCellRenderer().getDefaultClosedIcon()
And also can use the constants of L&F (colors, styles, icons).
In the iOS, I found only these standard icons.
But not folder icons...
I'm not quite sure exactly what you want - the folder icon from iOS? Could you explain a little better?
If it is a folder icon that you want, there's no quick way to get it from code - doing so would use private API's and your app is likely to be rejected from the app store.
If you want something like a folder icon, a good way to get it would be by taking a screenshot of the iPhone simulator and editing it to the right size etc.