经过数小时的研究，我能够知道可用于在保持图像纵横比的同时计算新的imageview高度的方法.

After hours of research, i was able to know the method that i can use to calculate new imageview height while maintaining image aspect ratio.

    BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true;

//Returns null, sizes are in the options variable
BitmapFactory.decodeFile("/sdcard/image.png", options);
int width = options.outWidth;
int height = options.outHeight;

//calculating image aspect ratio
float ratio =(float) height/(float) width;

//calculating my image height since i want it to be 360px wide
int newHeight = Math.round(ratio*360);

//setting the new dimentions
 imageview.getLayoutParams().width = 360;
 imageview.getLayoutParams().height = newHeight;

 //i'm using universal image loader to display image
 imaheview.post(new Runnable(){
  ImageLoader.getInstance().displayImage(imageuri,imageview,displayoptions);
 });