I am using Xamarin and I am new to it. I need to reference a dll which already uses System.Drawing due to which I am getting error. I know we can't use it because it is built aroung GDI+.
So plz let me know what should I do to successfully refer my dll. Even if I remove reference of System.Drawing from my dll then it is getting errors as it is using Bitmap, Image,Size etc. If I have to remove System.Drawing dll then how should I resolve the errors. Is there something else that can be used instead of Bitmap,Image,Size etc.
Plz help me and guide me with simple explanation as I am a beginner
As you found out there is no System.Drawing in Xamarin on mobile. Thus you might reuse sources (I assume you have those) into android(?) library and instead of Drawing types use Android (or iOS) ones. That would require code changes though.
Xamarin Droid already has such classes in framework. You don't need to reference external dll's. All you need to do to start using them is using Android.Graphics; in your class.
Related
I developed a Xamarin Cross Platform application that is working perfectly on Windows but when I try to recompile for Android I get the following error:
Can not resolve reference: `Windows.Foundation.UniversalApiContract
I use the Windows.Foundation.UniversalApiContract reference because of the Windows.Storage class (generate files in internal memory).
I understand that I may have to change the recording method on Android but I can't even get to that stage...
How do I resolve this situation?
Just as ToolmakerSteve said, Windows namespace relies on features that exist only in Windows. The reference should not be in the main .Net Standard library but in the UWP Application.
First, you can move the code to the Windows folder or set the #if Windows around it.
Second, you can write the code for each platform. I found the answer you can refer to Can not resolve reference: Windows.Foundation.UniversalApiContract in Android Application.
My .NET program I want to use in Java depends on SlimDX, a managed wrapper over DirectX. I add it to the project references as normal without hiccup.
However, when it comes to using JNI4NET's build.cmd, I get a CS0400 error suggesting that it does not know what the hell SLimDX is, even though I referenced it properly and put it in the folder with proxygen. It cannot be found in the 'global namespace'.
This ('global::net.sf.jni4net.utils.Convertor.StrongJp2C')
is one of the offending lines.
Actually, I figured it out! It's simple, there is a -dp option in proxygen to add .NET dependencies.
What is the exact difference between xamarin shared project and portable class library?
When to use shared library and when to use portable class library?
Is this possible to write native functionality in shared projects like showing alert,accessing camera and use it for both android and iOS?
Can anyone please explain me.
In shared projects each code file will be compiled for each destination (Android, iOS, Windows Phone etc). You are able to include platform specific code by using #if compiler directives.
When you want to access the camera you need to write the access code inside an #if block for all destinated platforms. This can mess up your code but it can be easier to find the different implementations.
Learn more: http://developer.xamarin.com/guides/cross-platform/application_fundamentals/shared_projects/
Protable Class Libraries (PCL) are compiled against a general .NET subset which is compatible to all platforms you want. So you can access System.Net.Http but you cannot access any platform specific code. If you want to access the camera inside the PCL code then you need to access it by a generalized interface via dependency injection. There are some pretty good frameworks helping you to archieve this goal. One of the most famous is MVVMCross (https://github.com/MvvmCross/MvvmCross/wiki). Learn more about PCL: http://developer.xamarin.com/guides/cross-platform/application_fundamentals/building_cross_platform_applications/sharing_code_options/#Portable_Class_Libraries
I personally perefer PCLs because the code is much easier to read without any compiler directives. Using MVVMCross you are able to use plenty of plugins via NuGet. So you don't need to write your own classes for camera access, showing alerts etc.
I am facing unknown problem while using Prism 4. We implement business solution in MVVM pattern. For that I have used
1. Microsoft.Expression.Interactions
2. System.Windows.Interactivity
3. GalaSoft.MvvmLight.Extras.WPF4
for Interaction.Triggers, CallMethodAction and EventToCommand.
<SWI:Interaction.Triggers>
<SWI:EventTrigger SourceObject="{Binding ElementName=txtName}" EventName="GotFocus">
<MEI:CallMethodAction TargetObject="{Binding Path=DataContext,ElementName=txtName}" MethodName="txtName_GotFocus"></MEI:CallMethodAction>
</SWI:EventTrigger>
<SWI:EventTrigger SourceObject="{Binding ElementName=txtName}" EventName="KeyUp">
<GMEWCMD:EventToCommand Command="{Binding Path=DataContext.cmdtxtNameKeyUpEvent,ElementName=txtName}" PassEventArgsToCommand="True">
</GMEWCMD:EventToCommand>
</SWI:EventTrigger>
</SWI:Interaction.Triggers>
Everything is working fine but now we required to make whole system loosely couple we choose prism 4. We already achieved this but above code create following problem as below.
Could not load file or assembly 'Microsoft.Expression.Interactions, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.
If I comment above code everything is working fine. I don't know what an issue. Does PRISM 4 not support above assemblies?
Please help us to get rid from this problem.
Thank you
This commonly happens to me when I reference both Microsoft.Expression.Interactions and System.Windows.Interactivity in a view that belongs to a module, but I fail to also add those references to the project that acts as the shell.
I had a similar problem with Prism in Visual Studio 2012. The XAML editor would fail with the same exception.
The solution was to install Microsoft Expression Blend SDK. The assembly should be part of SDK. Allegedly, it is necessary for binding between control events and commands in XAML and some code may require it.
I had the same problem during a Prism 6.1 composite app using .NET 4.5.2, where i was referencing in one of the modules (class library) the Microsoft.Expression.Interactions & System.Windows.Interactivity.
Eventually i had to reference the same dlls in the Desktop project (where bootstrapper and Shell belong)
I'm getting a null-object exception deep within XsltCompiledTransform, and I'd like to use the .Net Framework Source debugging feature to see what isn't being initialized, but even after following the directions for enabling it, I can't figure out how to step into the .Transform() method and start spelunking.
The tutorials I've found online say you can load the symbols for the framework library by using the Call Stack window while debugging, but this isn't useful when the callstack has yet to contain the library you want to debug. I've also tried loading symbols from the Modules window, but Step-Into still doesn't work.
Is the System.Xml.Xslt namespace source even available to step into when debugging?
If you have trouble fetching the sources on the fly, you might want to try out .NET Mass Downloader
As it looks, the sources for XsltCompiledTransform are included.