动态设置android:drawableLeft|Rig…

Drawable img_on, img_off;
Resources res = getResources();
img_off = res.getDrawable(R.drawable.btn_strip_mark_off);
//调用setCompoundDrawables时，必须调用Drawable.setBounds()方法,否则图片不显示
img_off.setBounds(0, 0, img_off.getMinimumWidth(),img_off.getMinimumHeight());
btn.setCompoundDrawables(img_off, null, null, null); //设置左图标