如何将项转换添加到VS2012 .proj msbuild文件中

Question

基于这个答案describing an item transform to convert image files from jpg to png，我进行了一个项转换，将.docx文件转换为.pdf。当我从我的projectname.proj构建文件调用它时，我会收到以下错误消息：

Error   1   The condition " '%(Extension)' == '.docx' " on the
"WordToPdf" target has a reference to item metadata. References to item 
metadata are not allowed in target conditions unless they are part of an item
transform. [project path]\.build\WordToPdf.Tasks.target 7   9

我怎么才能把这事做好？

我的目标是：

    <?xml version="1.0" encoding="utf-8" ?>
    <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
      <!-- $Id$ -->
      <Target Name="WordToPdf"
            Inputs="@(Content)"
            Outputs="@(Content -> '%(RootDir)%(Directory)%(Filename).pdf' )"
            Condition=" '%(Extension)' == '.docx' ">
        <ItemGroup>
          <Sublist Include="@(Content)" Condition=" '%(Extension)' == '.docx' " />
        </ItemGroup>
        <PropertyGroup>
          <PowerShellExe Condition=" '$(PowerShellExe)'=='' ">%WINDIR%\System32\WindowsPowerShell\v1.0\powershell.exe</PowerShellExe>
          <ScriptLocation Condition=" '$(ScriptLocation)'=='' ">.\WordToPdf.ps1</ScriptLocation>
        </PropertyGroup>

        <Exec Command="$(PowerShellExe) -NonInteractive -executionpolicy Unrestricted -command &quot;&amp; {&amp;&apos;$(ScriptLocation)&apos; -WordFilename &apos;/Input:%(Sublist.FullPath)&apos; }&quot;" />

        <Content Remove="@(Sublist)" />
        <Content Include="@(Sublist -> '%(RootDir)%(Directory)%(Filename).pdf' )" />
      </Target>
    </Project>

并从我的projectname.proj文件中从BeforeBuild目标调用它，如下所示：

  <Import Project="$(MSBuildTasksPath)\WordToPdf.Tasks.target" />

  ....

  <Target Name="BeforeBuild">
    <CallTarget Targets="WordToPdf" />
  </Target>

更新

这个目标有更多的错误，不仅仅是为了实现转换。对于将来的参考，下面是最后的工作代码：

<?xml version="1.0" encoding="utf-8" ?>
<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <!-- $Id$ -->
  <Target Name="WordToPdf"
      Inputs="@(ContentFiltered)"
      Outputs="@(ContentFiltered -> '%(RootDir)%(Directory)%(Filename).pdf' )"
      DependsOnTargets="FilterContent">
    <PropertyGroup>
      <PowerShellExe Condition=" '$(PowerShellExe)'=='' ">%WINDIR%\System32\WindowsPowerShell\v1.0\powershell.exe</PowerShellExe>
      <ScriptLocation Condition=" '$(ScriptLocation)'=='' ">.\WordToPdf.ps1</ScriptLocation>
    </PropertyGroup>

    <Exec Command="$(PowerShellExe) -NonInteractive -executionpolicy Unrestricted -command &quot;&amp; {&amp;&apos;$(ScriptLocation)&apos; -WordFilename &apos;%(ContentFiltered.FullPath)&apos; }&quot;" />

    <ItemGroup>
      <Content Remove="@(ContentFiltered)" />
      <Content Include="@(ContentFiltered -> '%(RootDir)%(Directory)%(Filename).pdf' )" />
    </ItemGroup>
  </Target>
  <!-- New target to pre-filter list -->
  <Target Name="FilterContent">
    <ItemGroup>
      <ContentFiltered Include="@(Content)" Condition="'%(Extension)' == '.docx'" />
    </ItemGroup>
  </Target>

</Project>

对于任何在这里搜索"msbuild到pdf项目转换“的人，下面是我的powershell脚本：

Param(
  [string]$WordFilename
)
$Word = New-Object -comobject Word.Application
$Doc=$Word.Documents.Open($WordFilename)
$Doc.saveas([ref](($WordFilename).replace("docx","pdf")), [ref]17)
$Doc.close()

将.docx文件添加到您的项目中，如果较新，则作为内容复制，如果docx文件较新，则创建pdf文件，然后将pdf文件复制到其输出位置。

Answer 1

您可以通过创建单独的目标来解决这一问题，该目标根据您的情况对项目进行预筛选--实际上，创建新的列表。

下面是示例-注意新的DependsOnTargets标记和更改的ContentFiltered名称：

  <Target Name="WordToPdf"
        Inputs="@(ContentFiltered)"
        Outputs="@(ContentFiltered -> '%(RootDir)%(Directory)%(Filename).pdf' )"
        DependsOnTargets="FilterContent">
    <!-- 
      ...
      your actual target body here 
      ...
      -->
  </Target>

  <!-- New target to pre-filter list -->
  <Target Name="FilterContent">
    <ItemGroup>
      <ContentFiltered Include="@(Content)" Condition="'%(Extension)' == '.docx'" />
    </ItemGroup>
  </Target>