在 MsBuild 中,是否可以创建一个 MSBuild 条件(或其他情况)来评估属性是否已“定义”(假设这是在某处为属性分配值之前)?
以下内容似乎有点笨拙而不可靠:
<PropertyGroup Label="Undefined State">
<Defined></Defined>
</PropertyGroup>
<Choose>
<When Condition="('$(Defined)' == '' OR '$(Defined)' != '')">
<Message Text="Defined is probably/likely/assuredly defined"/>
</When>
<Otherwise>
<Message Text="Defined is reportedly/maybe/possibly not defined"/>
</Otherwise>
<Choose>