title: How to convert DP, PX, SP among each other, especially DP and SP?
body: <p>I have known the difference among <strong>DP</strong>, <strong>SP</strong> and <strong>PX</strong>. And after searching this topic, I found nothing satisfying me completely. Maybe this post is a duplicate, but I still want to know what is the formula of converting from <strong>DP</strong> to <strong>PX</strong>, and <strong>DP</strong> to <strong>SP</strong>, from <strong>SP</strong> to <strong>PX</strong>, from <strong>PX</strong> to <strong>SP</strong>, from <strong>SP</strong> to <strong>DP</strong>, from <strong>DP</strong> to <strong>SP</strong>? I have known some codes to do this, but they are imperfect.</p>