package com.gyarmy.imageTest;



import java.io.IOException;



import android.media.ExifInterface;

import android.os.Bundle;

import android.os.Environment;

import android.app.Activity;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.graphics.BitmapFactory.Options;

import android.util.DisplayMetrics;

import android.view.Menu;

import android.view.View;

import android.widget.ImageView;



public class MainActivity extends Activity {

	

	public ImageView iv;

	

	

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        

        iv =(ImageView) findViewById(R.id.iv);

    }



    

    

    public void testBtn(View v){

    	

    	String path = Environment.getExternalStorageDirectory().toString();

    	path = path+"/Download/04.jpg";

    	System.out.println(path);

    	BitmapFactory.Options opts = new Options();

    	

    	//设置采样率

    	//屏幕的值

    	DisplayMetrics displayMetrics = getResources().getDisplayMetrics();

    	//宽和高的信息

    	int widthPixels = displayMetrics.widthPixels;

    	int heightPixels = displayMetrics.heightPixels;

    	

    	

    	//图片信息

    	try {

			ExifInterface exif = new ExifInterface(path);

			int imgWidth = exif.getAttributeInt(ExifInterface.TAG_IMAGE_WIDTH, 0);

			int imgHeight = exif.getAttributeInt(ExifInterface.TAG_IMAGE_LENGTH, 0);

			

			System.out.println(imgWidth +"===="+imgHeight);

			

			int sampleWidth = (int) (imgWidth*1f/widthPixels+0.5f);

			int sampleHeight = (int) (imgHeight*1f/heightPixels+0.5f);

			

			System.out.println(sampleWidth +"===="+sampleHeight);

			

			

			int sampleS = (int) (Math.sqrt(sampleWidth*sampleWidth + sampleHeight*sampleHeight)+0.5f);

			

			System.out.println(sampleS);

			

			opts.inSampleSize  = sampleS;

			

			//设置图片

			Bitmap decodeImg = BitmapFactory.decodeFile(path, opts);

			

			//加载图

			iv.setImageBitmap(decodeImg);

			

		} catch (Exception e) {

			// TODO Auto-generated catch block

			e.printStackTrace();

		}

    }



    

}