c# - How DragMove works? (Which properties it changes?) -

i making simple window in wpf (like overwolf), in overwolf there circle in top-left of screen , when drag it, moving corner simple animation. tried make same effect using doubleanimation on leftproperty works once (the first time drag working, the second stay dragged it).

my xaml:

<window x:class="overwoof.mainwindow"     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"     title="mainwindow"     name="main"     width="200"      height="200"      allowstransparency="true"      windowstyle='none'      ishittestvisible="true"     topmost="true"     background="transparent"     mouseleftbuttonup="ondragleave"     windowstartuplocation="manual"> <grid ishittestvisible="true" name="maingrid" minheight="200" minwidth="200">     <ellipse mouseleftbuttondown="dragstart" name="logo" width="100" height="100" fill="red" opacity="0.5" margin="12,24,66,37" ismanipulationenabled="true" /> </grid> 

my c# code:

private void dragstart(object sender, mouseeventargs e)     {         main.dragmove();     }      private void ondragleave(object sender, mouseeventargs e)     {         doubleanimation da = new doubleanimation();         da.from = main.left;         da.to = -20;         da.duration = new duration(timespan.fromseconds(0.2));         da.completed += new eventhandler(animationcompleted);         main.beginanimation(window.leftproperty, da);     } 

thx, bbln.

change da.to = -20; toda.to -= 20;