是否可以使用在MonoDroid中引用System.Net的可移植类库? [英] Is it possible to use a Portable Class Library that references System.Net in MonoDroid?

问题描述

来自>如何构建一个便携式类库的目标包?和 http://jpobst.blogspot.com/2012/04/mono-for-android-portable-libraries-in.html 我设法构建了一些使用可移植类的Monodroid示例程序图书馆.

但是，如果我的任何输入PCL都引用了System.Net程序集，则monodroid无法打包我的apk-因为它抱怨找不到System.Net.dll的文件.

据我了解(来自 http://docs.xamarin.com/android/about /assemblies )，MonoDroid将System.dll中的所有System.Net功能捆绑在一起.

有什么办法可以让MonoDroid使用这些引用System.Net的PCL?

• 有什么办法可以使Monodroid打包程序了解System.net->系统重定向吗?
• 或者我可以执行一些打包前步骤，以纠正"仅适用于monodroid的引用?
• 还有其他建议吗?

---

更新技术信息:

包装过程当前在以下级别失败:

"C:\Projects\Misc\MVVMCROSS\Sample - Tutorial\Tutorial\Tutorial.UI.Droid\Tutorial.UI.Droid.csproj" (SignAndroidPackage target) (1) ->
(_ResolveAssemblies target) -> 
  C:\Program Files (x86)\MSBuild\Novell\Novell.MonoDroid.Common.targets(441,2): error : Exception while loading assemblies: System.IO.FileNotFoundException: Could not load assembly 'System.Net, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e'. Perhaps it doesn't exist in the Mono for Android profile? [C:\Projects\Misc\MVVMCROSS\Sample - Tutorial\Tutorial\Tutorial.UI.Droid\Tutorial.UI.Droid.csproj]
C:\Program Files (x86)\MSBuild\Novell\Novell.MonoDroid.Common.targets(441,2): error : File name: 'System.Net.dll' [C:\Projects\Misc\MVVMCROSS\Sample - Tutorial\Tutorial\Tutorial.UI.Droid\Tutorial.UI.Droid.csproj]
C:\Program Files (x86)\MSBuild\Novell\Novell.MonoDroid.Common.targets(441,2): error :    at Monodroid.Tuner.MonoDroidResolver.Resolve(AssemblyNameReference reference, ReaderParameters parameters) [C:\Projects\Misc\MVVMCROSS\Sample - Tutorial\Tutorial\Tutorial.UI.Droid\Tutorial.UI.Droid.csproj]
C:\Program Files (x86)\MSBuild\Novell\Novell.MonoDroid.Common.targets(441,2): error :    at Xamarin.Android.Tasks.ResolveAssemblies.AddAssemblyReferences(List`1 assemblies, AssemblyDefinition assembly) [C:\Projects\Misc\MVVMCROSS\Sample - Tutorial\Tutorial\Tutorial.UI.Droid\Tutorial.UI.Droid.csproj]
C:\Program Files (x86)\MSBuild\Novell\Novell.MonoDroid.Common.targets(441,2): error :    at Xamarin.Android.Tasks.ResolveAssemblies.AddAssemblyReferences(List`1 assemblies, AssemblyDefinition assembly) [C:\Projects\Misc\MVVMCROSS\Sample - Tutorial\Tutorial\Tutorial.UI.Droid\Tutorial.UI.Droid.csproj]
C:\Program Files (x86)\MSBuild\Novell\Novell.MonoDroid.Common.targets(441,2): error :    at Xamarin.Android.Tasks.ResolveAssemblies.AddAssemblyReferences(List`1 assemblies, AssemblyDefinition assembly) [C:\Projects\Misc\MVVMCROSS\Sample - Tutorial\Tutorial\Tutorial.UI.Droid\Tutorial.UI.Droid.csproj]
C:\Program Files (x86)\MSBuild\Novell\Novell.MonoDroid.Common.targets(441,2): error :    at Xamarin.Android.Tasks.ResolveAssemblies.Execute() [C:\Projects\Misc\MVVMCROSS\Sample - Tutorial\Tutorial\Tutorial.UI.Droid\Tutorial.UI.Droid.csproj]

这是在MSBuild任务中发生的:

<!-- Find all the assemblies this app requires -->
<ResolveAssemblies
    Assemblies="$(ProjectDir)$(OutDir)$(TargetFileName);@(ReferencePath)"
    I18nAssemblies="$(MandroidI18n)"
    LinkMode="$(AndroidLinkMode)"
    ReferenceAssembliesDirectory="$(TargetFrameworkDirectory)">
        <Output TaskParameter="ResolvedAssemblies" ItemName="ResolvedAssemblies" />
  <Output TaskParameter="ResolvedUserAssemblies" ItemName="ResolvedUserAssemblies" />
  <Output TaskParameter="ResolvedFrameworkAssemblies" ItemName="ResolvedFrameworkAssemblies" />
  <Output TaskParameter="ResolvedSymbols" ItemName="ResolvedSymbols" />
  </ResolveAssemblies>

导入自:

  <UsingTask TaskName="Xamarin.Android.Tasks.ResolveAssemblies" AssemblyFile="Novell.MonoDroid.Build.Tasks.dll" />

解决方案

一个可能的解决方案(假设MonoDroid支持类型转发)是拥有一个System.Net.dll程序集，该程序集将相关类型转发到System.dll. >

在完整的.NET Framework中，我认为这些System.Net类型位于System.dll中，如果在.NET 4.0.3或4.5上查看System.Net.dll，您将看到 TypeForwardedToAttributes 允许那些对System.Net的类型引用可移植库中的.dll将被重定向到System.dll. Jeremy Likness在了解便携式图书馆上的博客文章系列有关这一切如何工作的一些细节.

可移植库中的引用引用System.Net.dll的全名.因此，由于您没有私钥，因此无法使用这些类型将自己转发的程序集生成正确签名的程序集.但是，MonoDroid可能会以不同的方式处理强名或签名验证.因此，您可能能够生成类型为MonoDroid可以接受的转发类型的System.Net.dll，并将其与您的MonoDroid应用程序打包在一起.

Following from How can I build a targetting pack for Portable Class Libraries? and the advice in http://jpobst.blogspot.com/2012/04/mono-for-android-portable-libraries-in.html I've managed to build some monodroid example programs which use Portable Class Libraries.

However, if any of my input PCLs reference the System.Net assembly, then monodroid fails to package my apk - because it complains about File Not Found for System.Net.dll.

As I understand it (from http://docs.xamarin.com/android/about/assemblies), MonoDroid bundles all the System.Net functionality inside System.dll.

Is there any way I can get MonoDroid to use these PCLs which reference System.Net?

• Is there any way I can get the monodroid packager to understand this System.net-> System redirection?
• Or is there some pre-package step I could run that would "correct" the referencing just for monodroid?
• Or any other suggestions?

---

Update with technical info:

The packaging process is currently failing at the level of:

"C:\Projects\Misc\MVVMCROSS\Sample - Tutorial\Tutorial\Tutorial.UI.Droid\Tutorial.UI.Droid.csproj" (SignAndroidPackage target) (1) ->
(_ResolveAssemblies target) -> 
  C:\Program Files (x86)\MSBuild\Novell\Novell.MonoDroid.Common.targets(441,2): error : Exception while loading assemblies: System.IO.FileNotFoundException: Could not load assembly 'System.Net, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e'. Perhaps it doesn't exist in the Mono for Android profile? [C:\Projects\Misc\MVVMCROSS\Sample - Tutorial\Tutorial\Tutorial.UI.Droid\Tutorial.UI.Droid.csproj]
C:\Program Files (x86)\MSBuild\Novell\Novell.MonoDroid.Common.targets(441,2): error : File name: 'System.Net.dll' [C:\Projects\Misc\MVVMCROSS\Sample - Tutorial\Tutorial\Tutorial.UI.Droid\Tutorial.UI.Droid.csproj]
C:\Program Files (x86)\MSBuild\Novell\Novell.MonoDroid.Common.targets(441,2): error :    at Monodroid.Tuner.MonoDroidResolver.Resolve(AssemblyNameReference reference, ReaderParameters parameters) [C:\Projects\Misc\MVVMCROSS\Sample - Tutorial\Tutorial\Tutorial.UI.Droid\Tutorial.UI.Droid.csproj]
C:\Program Files (x86)\MSBuild\Novell\Novell.MonoDroid.Common.targets(441,2): error :    at Xamarin.Android.Tasks.ResolveAssemblies.AddAssemblyReferences(List`1 assemblies, AssemblyDefinition assembly) [C:\Projects\Misc\MVVMCROSS\Sample - Tutorial\Tutorial\Tutorial.UI.Droid\Tutorial.UI.Droid.csproj]
C:\Program Files (x86)\MSBuild\Novell\Novell.MonoDroid.Common.targets(441,2): error :    at Xamarin.Android.Tasks.ResolveAssemblies.AddAssemblyReferences(List`1 assemblies, AssemblyDefinition assembly) [C:\Projects\Misc\MVVMCROSS\Sample - Tutorial\Tutorial\Tutorial.UI.Droid\Tutorial.UI.Droid.csproj]
C:\Program Files (x86)\MSBuild\Novell\Novell.MonoDroid.Common.targets(441,2): error :    at Xamarin.Android.Tasks.ResolveAssemblies.AddAssemblyReferences(List`1 assemblies, AssemblyDefinition assembly) [C:\Projects\Misc\MVVMCROSS\Sample - Tutorial\Tutorial\Tutorial.UI.Droid\Tutorial.UI.Droid.csproj]
C:\Program Files (x86)\MSBuild\Novell\Novell.MonoDroid.Common.targets(441,2): error :    at Xamarin.Android.Tasks.ResolveAssemblies.Execute() [C:\Projects\Misc\MVVMCROSS\Sample - Tutorial\Tutorial\Tutorial.UI.Droid\Tutorial.UI.Droid.csproj]

This is occurring within the MSBuild task:

<!-- Find all the assemblies this app requires -->
<ResolveAssemblies
    Assemblies="$(ProjectDir)$(OutDir)$(TargetFileName);@(ReferencePath)"
    I18nAssemblies="$(MandroidI18n)"
    LinkMode="$(AndroidLinkMode)"
    ReferenceAssembliesDirectory="$(TargetFrameworkDirectory)">
        <Output TaskParameter="ResolvedAssemblies" ItemName="ResolvedAssemblies" />
  <Output TaskParameter="ResolvedUserAssemblies" ItemName="ResolvedUserAssemblies" />
  <Output TaskParameter="ResolvedFrameworkAssemblies" ItemName="ResolvedFrameworkAssemblies" />
  <Output TaskParameter="ResolvedSymbols" ItemName="ResolvedSymbols" />
  </ResolveAssemblies>

imported from:

  <UsingTask TaskName="Xamarin.Android.Tasks.ResolveAssemblies" AssemblyFile="Novell.MonoDroid.Build.Tasks.dll" />

解决方案

A possible solution (assuming MonoDroid supports type forwarding) is to have a System.Net.dll assembly which type forwards the relevant types to System.dll.

In the full .NET Framework, I believe those System.Net types are in System.dll, and if you look in System.Net.dll on .NET 4.0.3 or 4.5, you will see TypeForwardedToAttributes for those types, which allow those type references to System.Net.dll in a portable library to be redirected to System.dll. Jeremy Likness's blog post series on Understanding Portable Libraries goes into some detail about how this all works.

The references in a portable library refer to the full strong name of System.Net.dll. So you couldn't produce a correctly signed assembly with those type forwards yourself, since you don't have the private key. However, MonoDroid may handle strong names or signature validation differently. So you might be able to produce a System.Net.dll with the type forwards that MonoDroid would accept, and package it with your MonoDroid application.

这篇关于是否可以使用在MonoDroid中引用System.Net的可移植类库?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！