017_01setImageBitmap引起的OOM分析

 1 package com.example.day17_01pictureloader;
 2 
 3  import android.app.Activity;
 4 import android.graphics.Bitmap;
 5 import android.graphics.BitmapFactory;
 6 import android.graphics.BitmapFactory.Options;
 7 import android.os.Bundle;
 8 import android.os.Debug;
 9 import android.os.Environment;
10 import android.view.Display;
11 import android.view.Menu;
12 import android.view.MenuItem;
13 import android.view.View;
14 import android.widget.ImageView;
15 
16 public class MainActivity extends Activity {
17 
18     @Override
19     protected void onCreate(Bundle savedInstanceState) {
20         super.onCreate(savedInstanceState);
21         setContentView(R.layout.activity_main);
22     }
23     
24     public void loadpicture(View v){
25         ImageView  iv_iamge = (ImageView) findViewById(R.id.iv_image);
26         //iv_iamge.setImageResource(R.drawable.fun1);
27         String path = Environment.getExternalStorageDirectory().getAbsolutePath()
28                 +"/DCIM/100ANDRO/cameras/dd.jpg";
29         Bitmap bm = BitmapFactory.decodeFile(path);    
30         iv_iamge.setImageBitmap(bm);    
31     }
32         
33     public void scaleloadpicture(View v){
34         String path = Environment.getExternalStorageDirectory().getAbsolutePath()
35                 +"/DCIM/100ANDRO/cameras/pp.jpeg";
36         //decode需要添加一些option
37         Options opt =new Options();
38         opt.inJustDecodeBounds = true;
39         Bitmap bm = BitmapFactory.decodeFile(path,opt);    
40         int original_width = opt.outWidth;
41         int original_heigth= opt.outHeight  ;
42         System.out.println("图片的原始宽高"+original_width+","+original_heigth);
43         
44         //获取屏幕的宽高
45         Display display = getWindowManager().getDefaultDisplay();
46         int screenWidth = display.getWidth();
47         int screenHeight = display.getHeight();
48         System.out.println("屏幕的宽和高: " + screenWidth + " * " + screenHeight);
49         
50         //计算缩放比例
51         int scale_width =  original_width/screenWidth ;
52         int scale_height =  original_heigth/screenHeight ;
53         int scale = scale_width>scale_height? scale_width:scale_height;
54         System.out.println("缩放的比例: " + scale  );
55 
56         //重新设置decode的参数，加上缩放比例的参数
57         opt.inJustDecodeBounds = false;
58        // opt.inScaled = scale;
59         opt.inSampleSize =scale;
60         bm = BitmapFactory.decodeFile(path,opt);
61         
62         //将缩放后的图片加载到imageview上
63         ImageView  iv_iamge = (ImageView) findViewById(R.id.iv_image);
64         iv_iamge.setImageBitmap(bm);
65     }
66 }

 1 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 2     xmlns:tools="http://schemas.android.com/tools"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     android:paddingBottom="@dimen/activity_vertical_margin"
 6     android:paddingLeft="@dimen/activity_horizontal_margin"
 7     android:paddingRight="@dimen/activity_horizontal_margin"
 8     android:paddingTop="@dimen/activity_vertical_margin"
 9     tools:context="com.example.day17_01pictureloader.MainActivity" 
10     android:orientation="vertical">
11 
12     <TextView
13         android:layout_width="wrap_content"
14         android:layout_height="wrap_content"
15         android:text="@string/hello_world" />
16         <Button
17         android:layout_width="wrap_content"
18         android:layout_height="wrap_content"
19         android:text="加载图片" 
20         android:onClick="loadpicture"/>
21            <Button
22         android:layout_width="wrap_content"
23         android:layout_height="wrap_content"
24         android:text="缩放加载图片" 
25         android:onClick="scaleloadpicture"/>
26     <ImageView
27         android:id="@+id/iv_image"
28         android:layout_width="wrap_content"
29         android:layout_height="wrap_content"
30          />
31 </LinearLayout>