Android缩放大图片

Android直接加载大图片会爆OOM,所以需要得到图片的宽和高，以及屏幕的宽和高，然后得到缩放比，就可以加载图片了。

public class MainActivity extends ActionBarActivity {

	private ImageView iv;
	
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        iv=(ImageView) findViewById(R.id.iv);
        
        WindowManager wm=(WindowManager) getSystemService(WINDOW_SERVICE);
        
        int height=wm.getDefaultDisplay().getHeight();
        int width=wm.getDefaultDisplay().getWidth();
        System.out.println("width:"+width+"---"+height);
        
        BitmapFactory.Options options = new Options();
        //设置为true，只会得到图片基本信息，不会加载图片
        options.inJustDecodeBounds=true;
        
        BitmapFactory.decodeFile("/mnt/sdcard/eeee.jpg",options);
        
        int imgWidth=options.outWidth;
        int imgHeight=options.outHeight;
        
        System.out.println("图片的宽和高："+imgHeight+"-----"+imgHeight);
        //设置缩放比
        int scale=1;
        int scaleX=imgWidth/width;
        int scaleY=imgHeight/height;
        
        if(scaleX>scaleY){
        	scale=scaleX;
        }else{
        	scale=scaleY;
        }
        System.out.println("thi probdfd:"+scale);
    	
        options.inSampleSize=scale;
        //设置为false,可以加载图片
        options.inJustDecodeBounds=false;
        Bitmap bitmap = BitmapFactory.decodeFile("/mnt/sdcard/eeee.jpg",options);
        
        iv.setImageBitmap(bitmap);
    }

}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.picdemo1.MainActivity" >

    <ImageView
        android:id="@+id/iv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</RelativeLayout>