layout = (MetroLayout) findViewById(R.id.layout);
ViewTreeObserver vto = layout.getViewTreeObserver();

vto.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener()
{
public boolean onPreDraw()
{
if (hasMeasured == false)
{

int height = metroLayout.getMeasuredHeight();
int width = metroLayout.getMeasuredWidth();
//獲取到寬度和高度后，可用于計算

hasMeasured = true;

}
return true;
}
});