示例：是基于的一种工具，该工具是为了解决任务而创建的。
代码如下（示例）： The following example uses the Choose and When elements for either/or processing. The properties and items for the project are set depending on the value of the Configuration property.
代码语言：javascript复制//添加头文件和库
<Project xmlns="https://schemas.microsoft.com/developer/msbuild/2003" >
<PropertyGroup>
<Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
<OutputType>Exe</OutputType>
<RootNamespace>ConsoleApplication1</RootNamespace>
<AssemblyName>ConsoleApplication1</AssemblyName>
<WarningLevel>4</WarningLevel>
</PropertyGroup>
<Choose>
<When Condition=" '$(Configuration)'=='Debug' ">
<PropertyGroup>
<DebugSymbols>true</DebugSymbols>
<DebugType>full</DebugType>
<Optimize>false</Optimize>
<OutputPath>.binDebug</OutputPath>
<DefineConstants>DEBUG;TRACE</DefineConstants>
</PropertyGroup>
<ItemGroup>
<Compile Include="UnitTesting*.cs" />
<Reference Include="NUnit.dll" />
</ItemGroup>
</When>
<When Condition=" '$(Configuration)'=='retail' ">
<PropertyGroup>
<DebugSymbols>false</DebugSymbols>
<Optimize>true</Optimize>
<OutputPath>.binRelease</OutputPath>
<DefineConstants>TRACE</DefineConstants>
</PropertyGroup>
</When>
</Choose>
<!-- Rest of Project -->
</Project>函数主体 This article applies to Visual Studio 2015. If you’re looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here Evaluates child elements to select one set of ItemGroup elements and/or PropertyGroup elements to evaluate.
代码语言：javascript复制//数据
<Choose>
<When Condition="'StringA'=='StringB'">... </When>
<Otherwise>... </Otherwise>
</Choose> 测试代码 The following project uses the Choose element to select which set of property values in the When elements to set. If the Condition attributes of both When elements evaluate to false, the property values in the Otherwise element are set.
代码语言：javascript复制//如果使用当前数据库，一定要保存文件否则会出错，
//当前数据库有自动保存操作，即使不操作，如果不保存，也会出错。
<Project
xmlns="https://schemas.microsoft.com/developer/msbuild/2003" >
<PropertyGroup>
<Configuration Condition="'$(Configuration)' == ''">Debug</Configuration>
<OutputType>Exe</OutputType>
<RootNamespace>ConsoleApplication1</RootNamespace>
<AssemblyName>ConsoleApplication1</AssemblyName>
<WarningLevel>4</WarningLevel>
</PropertyGroup>
<Choose>
<When Condition=" '$(Configuration)'=='debug' ">
<PropertyGroup>
<DebugSymbols>true</DebugSymbols>
<DebugType>full</DebugType>
<Optimize>false</Optimize>
<OutputPath>.binDebug</OutputPath>
<DefineConstants>DEBUG;TRACE</DefineConstants>
</PropertyGroup>
<ItemGroup>
<Compile Include="UnitTesting*.cs" />
<Reference Include="NUnit.dll" />
</ItemGroup>
</When>
<When Condition=" '$(Configuration)'=='retail' ">
<PropertyGroup>
<DebugSymbols>false</DebugSymbols>
<Optimize>true</Optimize>
<OutputPath>.binRelease</OutputPath>
<DefineConstants>TRACE</DefineConstants>
</PropertyGroup>
</When>
<Otherwise>
<PropertyGroup>
<DebugSymbols>true</DebugSymbols>
<Optimize>false</Optimize>
<OutputPath>.bin$(Configuration)</OutputPath>
<DefineConstants>DEBUG;TRACE</DefineConstants>
</PropertyGroup>
</Otherwise>
</Choose>
<Import Project="$(MSBuildBinPath)Microsoft.CSharp.targets" />
</Project> 总结
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