package com.loaderman.customviewdemo;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.util.Log;
import android.widget.ImageView;

public class MainActivity extends Activity {

    @Override
    
 
protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.cat);

        ImageView iv1 = (ImageView) findViewById(R.id.img1);
        iv1.setImageBitmap(bitmap);
        
 
int density = bitmap.getDensity();
        Log.d("loaderman", "density:" + density + "  width:" + bitmap.getWidth() + " height:" + bitmap.getHeight());

        int scaledDensity = density * 2;
        bitmap.setDensity(scaledDensity);
        Log.d("loaderman", "density:" + bitmap.getDensity() + "  width:" + bitmap.getWidth() + " height:" + bitmap.getHeight());
        ImageView iv2 
 
= (ImageView) findViewById(R.id.img2);
        iv2.setImageBitmap(bitmap);

    }


}

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content">

   <LinearLayout android:orientation="vertical"
       android:layout_width="fill_parent"
       android:layout_height="fill_parent">


      <ImageView
          android:id="@+id/img1"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:scaleType="fitCenter"

     />
      <ImageView
          android:id="@+id/img2"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:scaleType="fitCenter"

          />


   </LinearLayout>
</ScrollView>

效果: