c# - Storyboard targetting GridLength for WP8 -

i want make storyboard rowdefinition changing height, , found this me. problem when want create class gridlengthanimation, cannot make animationtimeline. because windows phone 8 not support this?

in case there work around making storyboard rowdefinition?

easiest way may put grids rows, , animate height-property this.

here xaml:

<grid x:name="layoutroot">     <grid.rowdefinitions>         <rowdefinition height="auto"/>         <rowdefinition height="auto"/>         <rowdefinition height="auto"/>         <rowdefinition height="auto"/>     </grid.rowdefinitions>      <grid background="aliceblue"           grid.row="0"           height="100"           tap="grid_tap"           cachemode="bitmapcache" />     <grid background="antiquewhite"           grid.row="1"           height="100"           tap="grid_tap"           cachemode="bitmapcache" />     <grid background="aqua"           grid.row="2"           height="100"           tap="grid_tap"           cachemode="bitmapcache" />     <grid background="aquamarine"           grid.row="3"           height="100"           tap="grid_tap"           cachemode="bitmapcache" />  </grid> 

and cs:

private void animateheight(grid grid) {     double newheight = grid.actualheight == 100 ? 300 : 100; //select height want animate      storyboard story = new storyboard();     doubleanimation animation = new doubleanimation();     animation.to = newheight;     animation.duration = timespan.fromseconds(0.5);      storyboard.settarget(animation, grid);     storyboard.settargetproperty(animation, new propertypath(grid.heightproperty));      story.children.add(animation);     story.begin(); }  private void grid_tap(object sender, system.windows.input.gestureeventargs e) {     grid grid = sender grid; //select grid tapped     animateheight(grid); } 

notice putted cachemode bitmapcache of grids. that's not necessary, gives more fluent animation, because static grids won't redrawed again in each frame.