<p>In a C++ file, I have a code like this:</p>

<pre><code>#if ACTIVATE
#   pragma message( "Activated" )
#else
#   pragma message( "Not Activated")
#endif
</code></pre>

<p>I want to set this ACTIVE define to 1 with the msbuild command line.</p>

<p>It tried this but it doesn't work:</p>

<pre><code>msbuild /p:DefineConstants="ACTIVATE=1"
</code></pre>

<p>Any idea?</p>

I think you want:
```
```
/p:DefineConstants=ACTIVATE
```
```