使用 ImageView 的 OutOfMemory 错误答案

【问题标题】：OutOfMemory Error using ImageView使用 ImageView 的 OutOfMemory 错误
【发布时间】：2013-12-28 17:33:45
【问题描述】：

我正在尝试使用 ImageView 制作壁纸集应用程序。我知道很难显示一堆图像（尤其是当图像是 1920x1080 时），我所做的是制作其他一堆分辨率更小（400x200）的图像，这些图像将显示在应用程序中，但是当用户试图设置一个图像作为壁纸它得到相同的图像，但具有更大的分辨率。我认为这会解决我的问题，但它没有，应用程序运行的时间比以前更长，但有一刻它失败了。我注意到在我将 3 张图片设置为壁纸后，该应用程序失败了。我尝试使用垃圾收集器，它不起作用。有什么想法吗？

这是我的代码。

package app.technozed.winterwallpapers;

import java.io.IOException;
import android.os.Bundle;
import android.app.Activity;
import android.app.WallpaperManager;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

public class MainActivity extends Activity implements OnClickListener {

ImageView display;
int toPhone;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    toPhone = R.drawable.wal1;

    display = (ImageView) findViewById(R.id.WPdisplay);
    ImageView image1 = (ImageView) findViewById(R.id.WPimg1);
    ImageView image2 = (ImageView) findViewById(R.id.WPimg2);
    ImageView image3 = (ImageView) findViewById(R.id.WPimg3);
    ImageView image4 = (ImageView) findViewById(R.id.WPimg4);
    ImageView image5 = (ImageView) findViewById(R.id.WPimg5);
    ImageView image6 = (ImageView) findViewById(R.id.WPimg6);
    ImageView image7 = (ImageView) findViewById(R.id.WPimg7);
    ImageView image8 = (ImageView) findViewById(R.id.WPimg8);
    ImageView image9 = (ImageView) findViewById(R.id.WPimg9);
    ImageView image10 = (ImageView) findViewById(R.id.WPimg10);
    ImageView image11 = (ImageView) findViewById(R.id.WPimg11);
    ImageView image12 = (ImageView) findViewById(R.id.WPimg12);
    ImageView image13 = (ImageView) findViewById(R.id.WPimg13);
    ImageView image14 = (ImageView) findViewById(R.id.WPimg14);
    ImageView image15 = (ImageView) findViewById(R.id.WPimg15);
    ImageView image16 = (ImageView) findViewById(R.id.WPimg16);
    ImageView image17 = (ImageView) findViewById(R.id.WPimg17);
    ImageView image18 = (ImageView) findViewById(R.id.WPimg18);
    ImageView image19 = (ImageView) findViewById(R.id.WPimg19);
    ImageView image20 = (ImageView) findViewById(R.id.WPimg20);
    ImageView image21 = (ImageView) findViewById(R.id.WPimg21);
    ImageView image22 = (ImageView) findViewById(R.id.WPimg22);
    ImageView image23 = (ImageView) findViewById(R.id.WPimg23);
    ImageView image24 = (ImageView) findViewById(R.id.WPimg24);
    ImageView image25 = (ImageView) findViewById(R.id.WPimg25);
    ImageView image26 = (ImageView) findViewById(R.id.WPimg26);
    ImageView image27 = (ImageView) findViewById(R.id.WPimg27);
    ImageView image28 = (ImageView) findViewById(R.id.WPimg28);
    ImageView image29 = (ImageView) findViewById(R.id.WPimg29);
    ImageView image30 = (ImageView) findViewById(R.id.WPimg30);
    Button setWall = (Button) findViewById(R.id.BsetWall);
    image1.setOnClickListener(this);
    image2.setOnClickListener(this);
    image3.setOnClickListener(this);
    image4.setOnClickListener(this);
    image5.setOnClickListener(this);
    image6.setOnClickListener(this);
    image7.setOnClickListener(this);
    image8.setOnClickListener(this);
    image9.setOnClickListener(this);
    image10.setOnClickListener(this);
    image11.setOnClickListener(this);
    image12.setOnClickListener(this);
    image13.setOnClickListener(this);
    image14.setOnClickListener(this);
    image15.setOnClickListener(this);
    image16.setOnClickListener(this);
    image17.setOnClickListener(this);
    image18.setOnClickListener(this);
    image19.setOnClickListener(this);
    image20.setOnClickListener(this);
    image21.setOnClickListener(this);
    image22.setOnClickListener(this);
    image23.setOnClickListener(this);
    image24.setOnClickListener(this);
    image25.setOnClickListener(this);
    image26.setOnClickListener(this);
    image27.setOnClickListener(this);
    image28.setOnClickListener(this);
    image29.setOnClickListener(this);
    image30.setOnClickListener(this);
    setWall.setOnClickListener(this);
    }

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}


@Override
public void onClick(View v) {
    switch (v.getId()){
    case R.id.WPimg1:
         display.setImageResource(R.drawable.wal1);
         toPhone = R.drawable.wal1;
         break;
    case R.id.WPimg2:
         display.setImageResource(R.drawable.wal2);
         toPhone = R.drawable.wal2;
         break;
    case R.id.WPimg3:
         display.setImageResource(R.drawable.wal3);
         toPhone = R.drawable.wal3;
         break;
    case R.id.WPimg4:
         display.setImageResource(R.drawable.wal4);
         toPhone = R.drawable.wal4;
         break;
    case R.id.WPimg5:
         display.setImageResource(R.drawable.wal5);
         toPhone = R.drawable.wal5;
         break;
    case R.id.WPimg6:
         display.setImageResource(R.drawable.wal6);
         toPhone = R.drawable.wal6;
         break;
    case R.id.WPimg7:
         display.setImageResource(R.drawable.wal7);
         toPhone = R.drawable.wal7;
         break;
    case R.id.WPimg8:
         display.setImageResource(R.drawable.wal8);
         toPhone = R.drawable.wal8;
         break;
    case R.id.WPimg9:
         display.setImageResource(R.drawable.wal9);
         toPhone = R.drawable.wal9;;
         break;
    case R.id.WPimg10:
         display.setImageResource(R.drawable.wal10);
         toPhone = R.drawable.wal10;
         break;
    case R.id.WPimg11:
         display.setImageResource(R.drawable.wal11);
         toPhone = R.drawable.wal11;
         break;
    case R.id.WPimg12:
         display.setImageResource(R.drawable.wal12);
         toPhone = R.drawable.wal12;
         break;
    case R.id.WPimg13:
         display.setImageResource(R.drawable.wal13);
         toPhone = R.drawable.wal13;
         break;
    case R.id.WPimg14:
         display.setImageResource(R.drawable.wal14);
         toPhone = R.drawable.wal14;
         break;
    case R.id.WPimg15:
         display.setImageResource(R.drawable.wal15);
         toPhone = R.drawable.wal15;
         break;
    case R.id.WPimg16:
         display.setImageResource(R.drawable.wal16);
         toPhone = R.drawable.wal16;
         break;
    case R.id.WPimg17:
         display.setImageResource(R.drawable.wal17);
         toPhone = R.drawable.wal17;
         break;
    case R.id.WPimg18:
         display.setImageResource(R.drawable.wal18);
         toPhone = R.drawable.wal18;
         break;
    case R.id.WPimg19:
         display.setImageResource(R.drawable.wal19);
         toPhone = R.drawable.wal19;
         break;
    case R.id.WPimg20:
         display.setImageResource(R.drawable.wal20);
         toPhone = R.drawable.wal20;
         break;
    case R.id.WPimg21:
         display.setImageResource(R.drawable.wal21);
         toPhone = R.drawable.wal21;
         break;
    case R.id.WPimg22:
         display.setImageResource(R.drawable.wal22);
         toPhone = R.drawable.wal22;
         break;
    case R.id.WPimg23:
         display.setImageResource(R.drawable.wal23);
         toPhone = R.drawable.wal23;
         break;
    case R.id.WPimg24:
         display.setImageResource(R.drawable.wal24);
         toPhone = R.drawable.wal24;
         break;
    case R.id.WPimg25:
         display.setImageResource(R.drawable.wal25);
         toPhone = R.drawable.wal25;
         break;
    case R.id.WPimg26:
         display.setImageResource(R.drawable.wal26);
         toPhone = R.drawable.wal26;
         break;
    case R.id.WPimg27:
         display.setImageResource(R.drawable.wal27);
         toPhone = R.drawable.wal27;
         break;
    case R.id.WPimg28:
         display.setImageResource(R.drawable.wal28);
         toPhone = R.drawable.wal28;
         break;
    case R.id.WPimg29:
         display.setImageResource(R.drawable.wal29);
         toPhone = R.drawable.wal29;
         break;
    case R.id.WPimg30:
         display.setImageResource(R.drawable.wal30);
         toPhone = R.drawable.wal30;
         break;
    case R.id.BsetWall:
         try{
                  WallpaperManager.getInstance(getApplicationContext()).setResource(toPhone);
             Toast.makeText(getApplicationContext(), "Wallpaper was set!", Toast.LENGTH_SHORT).show();
         } catch(IOException e) {
             e.printStackTrace();
             Toast.makeText(getApplicationContext(), "No privileges!", Toast.LENGTH_SHORT).show();
         }
         break;
    }

    }

    }

这里是 LogCat。

--- allocation failed for scaled bitmap
Shutting down VM
threadid=1: thread exiting with uncaught exception (group=0x41618ba8)
FATAL EXCEPTION: main
Process: app.technozed.winterwallpapers, PID: 2574
java.lang.OutOfMemoryError
at android.graphics.BitmapFactory.nativeDecodeAsset(Native Method)
at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:587)
at android.graphics.BitmapFactory.decodeResourceStream(BitmapFactory.java:422)
at android.graphics.drawable.Drawable.createFromResourceStream(Drawable.java:840)
at android.content.res.Resources.loadDrawable(Resources.java:2110)
at android.content.res.Resources.getDrawable(Resources.java:700)
at android.widget.ImageView.resolveUri(ImageView.java:638)
at android.widget.ImageView.setImageResource(ImageView.java:367)
at app.technozed.winterwallpapers.MainActivity.onClick(MainActivity.java:143)
at android.view.View.performClick(View.java:4438)
at android.view.View$PerformClick.run(View.java:18422)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)

【问题讨论】：

Out of Memory error with Bitmap 的可能重复项
我没有使用位图。
基本问题，您的图像很大，需要按比例缩小。还有这么多的imageviews。设计变更需要考虑的事项
图片存放在哪个文件夹？
@KickAss drawable-hdpi

标签： android out-of-memory

【解决方案1】：

将图像移动到名为“drawable-nodpi”的新文件夹中。

原因

不同drawable文件夹中的图片由android系统以不同的内存分配打开，hdpi意味着即使图像很小也会占用大量内存。

drawable-nodpi 是节省内存的最佳选择。

【讨论】：

谢谢。我必须过滤很多 SO 答案才能找到这个。我将图像放入 xxhdpi 中，问题就消失了。
你是救命稻草
@David 我不明白您的问题是如何通过在 xxhdpi 中添加图像来解决的，这不违反公认的答案，在文件夹中作为 xxhdpi 意味着它会占用大量内存吗？
@KickAss 非常感谢，我在 Android Studio 中使用 Memory Monitor 对其进行了测试，假设这样的信息应该在 Google / Android / Android Studio 应用程序的首页上“固定提示”，从 110MB 减少到在 drawable 文件夹中加载 5 张 jpeg 图像（700x400），当我将它添加到“drawable-nodpi”文件夹中时大约 40MB。

【解决方案2】：

要修复 OutOfMemory，您应该这样做：

BitmapFactory.Options options=new BitmapFactory.Options();
options.inSampleSize = 8;
Bitmap preview_bitmap=BitmapFactory.decodeStream(is,null,options);

此 inSampleSize 选项可减少内存消耗。

这是一个完整的方法。首先它读取图像大小而不解码内容本身。然后找到最佳的 inSampleSize 值，应该是 2 的幂。最后解码图像。

//decodes image and scales it to reduce memory consumption
private Bitmap decodeFile(File f){
try {
    //Decode image size
    BitmapFactory.Options o = new BitmapFactory.Options();
    o.inJustDecodeBounds = true;
    BitmapFactory.decodeStream(new FileInputStream(f),null,o);

    //The new size we want to scale to
    final int REQUIRED_SIZE=70;

    //Find the correct scale value. It should be the power of 2.
    int scale=1;
    while(o.outWidth/scale/2>=REQUIRED_SIZE && o.outHeight/scale/2>=REQUIRED_SIZE)
        scale*=2;

    //Decode with inSampleSize
    BitmapFactory.Options o2 = new BitmapFactory.Options();
    o2.inSampleSize=scale;
    return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
} catch (FileNotFoundException e) {}
return null;
}

【讨论】：