MSBuild：给定绝对路径，如何获取文件的相对路径？

Question

我遇到一堆绝对路径的情况，我想将它们转换为基于MSBuild的另一个目录的相对路径。这是我到目前为止的代码：

<PropertyGroup>
    <FromPath>$(Bar)</FromPath>
</PropertyGroup>
<ItemGroup>
    <AbsolutePaths Include="@(Foo)" Exclude="@(Baz)" />
    <PathsRelativeToBar Include="@(AbsolutePaths->'???')" /> <!-- What goes here? -->
</ItemGroup>

任何帮助，将不胜感激，谢谢！

编辑：我在这个 StackOverflow问题中找到了一个基于C＃的解决方案，但是我不确定如何（或是否有可能）将其转换为MSBuild。

Answer 1

MSBuild中有一个本地函数，称为“ MakeRelative”

这是如何使用它。

<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build" ToolsVersion="4.5" >
    <PropertyGroup>
        <Bar>c:\temp\msbuild-sample\2</Bar>
        <FromPath>$(Bar)</FromPath>
    </PropertyGroup>
    <ItemGroup>
        <AbsolutePaths Include="c:\temp\msbuild-sample\1\**\*.txt" />
    </ItemGroup>
    <Target Name="Build">
        <ItemGroup>
            <PathsRelativeToBar Include="@(AbsolutePaths)">
                <!-- Here is the magic... we're adding a piece of metadata with the relative path -->
                <RelativePath>$([MSBuild]::MakeRelative($(FromPath), %(AbsolutePaths.FullPath)))</RelativePath>
            </PathsRelativeToBar>
        </ItemGroup>
        <Message Text="----- Absolute paths -----" />
        <Message Text="%(AbsolutePaths.FullPath)" />
        <Message Text="----- Relative paths (showing full path) -----" />
        <Message Text="%(PathsRelativeToBar.FullPath)" />
        <Message Text="----- Relative paths (relative to $(FromPath)) -----" />
        <Message Text="%(PathsRelativeToBar.RelativePath)" />
    </Target>
</Project>

这是我当前环境的快速浏览

C:\temp\msbuild-sample>dir /s /b

C:\temp\msbuild-sample\1
C:\temp\msbuild-sample\sample.build
C:\temp\msbuild-sample\1\1.1
C:\temp\msbuild-sample\1\1.txt
C:\temp\msbuild-sample\1\2.txt
C:\temp\msbuild-sample\1\1.1\3.txt
C:\temp\msbuild-sample\1\1.1\4.txt

这是输出。

----- Absolute paths -----
c:\temp\msbuild-sample\1\1.1\3.txt
c:\temp\msbuild-sample\1\1.1\4.txt
c:\temp\msbuild-sample\1\1.txt
c:\temp\msbuild-sample\1\2.txt
----- Relative paths (showing full path) -----
c:\temp\msbuild-sample\1\1.1\3.txt
c:\temp\msbuild-sample\1\1.1\4.txt
c:\temp\msbuild-sample\1\1.txt
c:\temp\msbuild-sample\1\2.txt
----- Relative paths (relative to c:\temp\msbuild-sample\2) -----
..\1\1.1\3.txt
..\1\1.1\4.txt
..\1\1.txt
..\1\2.txt

希望这可以帮助 ：）