在oncreate中，使用getheight等函数不能获得控件大小，得到的为0
应使用其他方法
Resources res = getResources();
final ImageView view=(ImageView)findViewById(R.id.IV_about);
final Drawable drawable=res.getDrawable(R.drawable.ic_about);
DisplayMetrics dm = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(dm);
final int screen_height = dm.heightPixels ;//高度
ViewTreeObserver vto = view.getViewTreeObserver();
vto.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
public boolean onPreDraw() {
int height = (int) ((float) view.getMeasuredWidth()/drawable.getMinimumWidth() * drawable.getMinimumHeight());
int width = view.getMeasuredWidth();
LinearLayout.LayoutParams linearParams =(LinearLayout.LayoutParams) view.getLayoutParams(); //取控件textView当前的布局参数
linearParams.height = height;
linearParams.width = view.getMeasuredWidth();
linearParams.topMargin=screen_height/10;
view.setLayoutParams(linearParams);
view.setImageResource(R.drawable.ic_about);