android 通过字符串来获取R下面资源的ID 值

方法一：

try{
Field field=R.drawable.class.getField("icon");
int i= field.getInt(new R.drawable());
Log.d("icon",i+"");
}catch(Exception e){
Log.e("icon",e.toString());
}

方法二：

Resources res=getResources();
int i=res.getIdentifier("icon","drawable",getPackageName());

Log.i("res",Integer.toString(i));