在Xamarin Android项目中的android Assets中添加文件夹会引发Build Error

寸阳分阴须爱惜，休负春色与时光。这篇文章主要讲述在Xamarin Android项目中的android Assets中添加文件夹会引发Build Error相关的知识，希望能为你提供帮助。
无法在Xamarin android项目中的Assets中添加目录和子目录。
IDE：适用于Mac的Visual Studio社区版本：7.3.2（版本12）
操作系统：MacOS High Sierra版本：10.13.2
错误：/ Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Common.targets(2,2）：错误MSB3025：源文件“Assets / Dir /”实际上是一个目录。 “复制”任务不支持复制目录。（MSB3025）（assetsCheck）
/Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Common.targets(2,2）：错误MSB3025：源文件“Assets / Dir / SubDir /”实际上是一个目录。 “复制”任务不支持复制目录。（MSB3025）（assetsCheck）
注意能够在Windows 10系统中使用Visual Studio社区成功构建。
.csproj文件

< ?xml version="1.0" encoding="utf-8"?> < Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003"> < Import Project="..packagesXamarin.Build.Download.0.4.3uildXamarin.Build.Download.props" Condition="Exists('..packagesXamarin.Build.Download.0.4.3uildXamarin.Build.Download.props')" /> < PropertyGroup> < Configuration Condition=" '$(Configuration)' == '' "> Debug< /Configuration> < Platform Condition=" '$(Platform)' == '' "> AnyCPU< /Platform> < ProjectGuid> {A6BF443D-8B89-4044-B951-E346FA8E68D3}< /ProjectGuid> < ProjectTypeGuids> {EFBA0AD7-5A72-4C68-AF49-83D382785DCF}; {FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}< /ProjectTypeGuids> < OutputType> Library< /OutputType> < RootNamespace> ScormReader.Droid< /RootNamespace> < AssemblyName> ScormReader.Droid< /AssemblyName> < TargetFrameworkVersion> v8.0< /TargetFrameworkVersion> < AndroidApplication> True< /AndroidApplication> < AndroidResgenFile> ResourcesResource.designer.cs< /AndroidResgenFile> < AndroidResgenClass> Resource< /AndroidResgenClass> < AndroidManifest> PropertiesAndroidManifest.xml< /AndroidManifest> < MonoAndroidResourcePrefix> Resources< /MonoAndroidResourcePrefix> < MonoAndroidAssetsPrefix> Assets< /MonoAndroidAssetsPrefix> < AndroidUseLatestPlatformSdk> true< /AndroidUseLatestPlatformSdk> < /PropertyGroup> < PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' "> < DebugSymbols> true< /DebugSymbols> < DebugType> full< /DebugType> < Optimize> false< /Optimize> < OutputPath> binDebug< /OutputPath> < DefineConstants> DEBUG; < /DefineConstants> < ErrorReport> prompt< /ErrorReport> < WarningLevel> 4< /WarningLevel> < AndroidLinkMode> None< /AndroidLinkMode> < AndroidSupportedAbis> arm64-v8a; armeabi; armeabi-v7a; x86< /AndroidSupportedAbis> < /PropertyGroup> < PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' "> < DebugSymbols> true< /DebugSymbols> < DebugType> pdbonly< /DebugType> < Optimize> true< /Optimize> < OutputPath> binRelease< /OutputPath> < ErrorReport> prompt< /ErrorReport> < WarningLevel> 4< /WarningLevel> < AndroidManagedSymbols> true< /AndroidManagedSymbols> < AndroidUseSharedRuntime> false< /AndroidUseSharedRuntime> < /PropertyGroup> < ItemGroup> < Reference Include="System" /> < Reference Include="System.Xml" /> < Reference Include="System.Core" /> < Reference Include="Mono.Android" /> < Reference Include="Xamarin.Android.Support.Annotations"> < HintPath> ..packagesXamarin.Android.Support.Annotations.25.3.1libMonoAndroid70Xamarin.Android.Support.Annotations.dll< /HintPath> < /Reference> < Reference Include="Xamarin.Android.Support.Compat"> < HintPath> ..packagesXamarin.Android.Support.Compat.25.3.1libMonoAndroid70Xamarin.Android.Support.Compat.dll< /HintPath> < /Reference> < Reference Include="Xamarin.Android.Support.Core.UI"> < HintPath> ..packagesXamarin.Android.Support.Core.UI.25.3.1libMonoAndroid70Xamarin.Android.Support.Core.UI.dll< /HintPath> < /Reference> < Reference Include="Xamarin.Android.Support.Core.Utils"> < HintPath> ..packagesXamarin.Android.Support.Core.Utils.25.3.1libMonoAndroid70Xamarin.Android.Support.Core.Utils.dll< /HintPath> < /Reference> < Reference Include="Xamarin.Android.Support.Media.Compat"> < HintPath> ..packagesXamarin.Android.Support.Media.Compat.25.3.1libMonoAndroid70Xamarin.Android.Support.Media.Compat.dll< /HintPath> < /Reference> < Reference Include="Xamarin.Android.Support.Fragment"> < HintPath> ..packagesXamarin.Android.Support.Fragment.25.3.1libMonoAndroid70Xamarin.Android.Support.Fragment.dll< /HintPath> < /Reference> < Reference Include="Xamarin.Android.Support.Vector.Drawable"> < HintPath> ..packagesXamarin.Android.Support.Vector.Drawable.25.3.1libMonoAndroid70Xamarin.Android.Support.Vector.Drawable.dll< /HintPath> < /Reference> < Reference Include="Xamarin.Android.Support.Animated.Vector.Drawable"> < HintPath> ..packagesXamarin.Android.Support.Animated.Vector.Drawable.25.3.1libMonoAndroid70Xamarin.Android.Support.Animated.Vector.Drawable.dll< /HintPath> < /Reference> < Reference Include="Xamarin.Android.Support.v7.AppCompat"> < HintPath> ..packagesXamarin.Android.Support.v7.AppCompat.25.3.1libMonoAndroid70Xamarin.Android.Support.v7.AppCompat.dll< /HintPath> < /Reference> < /ItemGroup> < ItemGroup> < Compile Include="MainActivity.cs" /> < Compile Include="ResourcesResource.designer.cs" /> < Compile Include="PropertiesAssemblyInfo.cs" /> < /ItemGroup> < ItemGroup> < None Include="ResourcesAboutResources.txt" /> < None Include="PropertiesAndroidManifest.xml" /> < None Include="AssetsAboutAssets.txt" /> < None Include="packages.config" /> < /ItemGroup> < ItemGroup> < AndroidResource Include="ResourceslayoutMain.axml" /> < AndroidResource Include="ResourcesvaluesStrings.xml" /> < AndroidResource Include="Resourcesmipmap-hdpiIcon.png" /> < AndroidResource Include="Resourcesmipmap-mdpiIcon.png" /> < AndroidResource Include="Resourcesmipmap-xhdpiIcon.png" /> < AndroidResource Include="Resourcesmipmap-xxhdpiIcon.png" /> < AndroidResource Include="Resourcesmipmap-xxxhdpiIcon.png" /> < /ItemGroup> < ItemGroup> < Folder Include="Resourcesdrawable" /> < /ItemGroup> < ItemGroup> < /ItemGroup> < ItemGroup> < /ItemGroup> < ItemGroup> < AndroidAsset Include="AssetsParent" /> < AndroidAsset Include="AssetsParentChild" /> < /ItemGroup> < Import Project="$(MSBuildExtensionsPath)XamarinAndroidXamarin.Android.CSharp.targets" /> < Import Project="..packagesXamarin.Build.Download.0.4.3uildXamarin.Build.Download.targets" Condition="Exists('..packagesXamarin.Build.Download.0.4.3uildXamarin.Build.Download.targets')" /> < Import Project="..packagesXamarin.Android.Support.Annotations.25.3.1uildMonoAndroid70Xamarin.Android.Support.Annotations.targets" Condition="Exists('..packagesXamarin.Android.Support.Annotations.25.3.1uildMonoAndroid70Xamarin.Android.Support.Annotations.targets')" /> < Import Project="..packagesXamarin.Android.Support.Compat.25.3.1uildMonoAndroid70Xamarin.Android.Support.Compat.targets" Condition="Exists('..packagesXamarin.Android.Support.Compat.25.3.1uildMonoAndroid70Xamarin.Android.Support.Compat.targets')" /> < Import Project="..packagesXamarin.Android.Support.Core.UI.25.3.1uildMonoAndroid70Xamarin.Android.Support.Core.UI.targets" Condition="Exists('..packagesXamarin.Android.Support.Core.UI.25.3.1uildMonoAndroid70Xamarin.Android.Support.Core.UI.targets')" /> < Import Project="..packagesXamarin.Android.Support.Core.Utils.25.3.1uildMonoAndroid70Xamarin.Android.Support.Core.Utils.targets" Condition="Exists('..packagesXamarin.Android.Support.Core.Utils.25.3.1uildMonoAndroid70Xamarin.Android.Support.Core.Utils.targets')" /> < Import Project="..packagesXamarin.Android.Support.Media.Compat.25.3.1uildMonoAndroid70Xamarin.Android.Support.Media.Compat.targets" Condition="Exists('..packagesXamarin.Android.Support.Media.Compat.25.3.1uildMonoAndroid70Xamarin.Android.Support.Media.Compat.targets')" /> < Import Project="..packagesXamarin.Android.Support.Fragment.25.3.1uildMonoAndroid70Xamarin.Android.Support.Fragment.targets" Condition="Exists('..packagesXamarin.Android.Support.Fragment.25.3.1uildMonoAndroid70Xamarin.Android.Support.Fragment.targets')" /> < Import Project="..packagesXamarin.Android.Support.Vector.Drawable.25.3.1uildMonoAndroid70Xamarin.Android.Support.Vector.Drawable.targets" Condition="Exists('..packagesXamarin.Android.Support.Vector.Drawable.25.3.1uildMonoAndroid70Xamarin.Android.Support.Vector.Drawable.targets')" /> < Import Project="..packagesXamarin.Android.Support.Animated.Vector.Drawable.25.3.1uildMonoAndroid70Xamarin.Android.Support.Animated.Vector.Drawable.targets" Condition="Exists('..packagesXamarin.Android.Support.Animated.Vector.Drawable.25.3.1uildMonoAndroid70Xamarin.Android.Support.Animated.Vector.Drawable.targets')" /> < Import Project="..packagesXamarin.Android.Support.v7.AppCompat.25.3.1uildMonoAndroid70Xamarin.Android.Support.v7.AppCompat.targets" Condition="Exists('..packagesXamarin.Android.Support.v7.AppCompat.25.3.1uildMonoAndroid70Xamarin.Android.Support.v7.AppCompat.targets')" /> < /Project>

答案

“复制”任务不支持复制目录。

我在我的MacOS上重现了你的问题，并找到了修复程序。添加子目录时，csproj文件添加了一个导致此错误的项目。编辑csproj文件并删除引用子目录的行将解决此问题。
Solution :我的.csproj文件：

< ItemGroup> < AndroidAsset Include="AssetsNew Folderhi.txt"> < Generator> RazorTemplatePreprocessor< /Generator> < LastGenOutput> hi.cs< /LastGenOutput> < /AndroidAsset> < AndroidAsset Include="AssetsNew Folder1" /> < /ItemGroup>

删除引用子目录的第一个AndroidAsset：
【在Xamarin Android项目中的android Assets中添加文件夹会引发Build Error】