Android 内存不足位图

Question

我的应用有问题:

java.lang.OutOfMemoryError: Failed to allocate a 1136368 byte allocation with 127432 free bytes
        at dalvik.system.VMRuntime.newNonMovableArray(Native Method)
        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:636)
        at android.widget.ImageView.setImageResource(ImageView.java:366)
        at com.scoutapp.lite.ImageLoader.DisplayImage(ImageLoader.java:40)
        at com.scoutapp.lite.CustomArrayAdapter.getView(CustomArrayAdapter.java:49)
        at android.widget.AbsListView.obtainView(AbsListView.java:2242)
        at android.widget.ListView.makeAndAddView(ListView.java:1790)
        at android.widget.ListView.fillDown(ListView.java:691)
        at android.widget.ListView.fillGap(ListView.java:655)
        at android.widget.AbsListView.trackMotionScroll(AbsListView.java:5148)
        at android.widget.AbsListView$FlingRunnable.run(AbsListView.java:4259)
        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
        at android.view.Choreographer.doCallbacks(Choreographer.java:574)
        at android.view.Choreographer.doFrame(Choreographer.java:543)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
        at android.os.Handler.handleCallback(Handler.java:733)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:136)
        at android.app.ActivityThread.main(ActivityThread.java:5019)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)

基本上我有一个 Activity ，其中有一个包含一些图像的列表。它们加载正确，但是当我向下滚动时，我会因这个错误而强制关闭。在这里我发布我的两个类(class):

public class CustomArrayAdapter extends ArrayAdapter<String> {
private final Context context;
private final String[] values;
private final String[] img;
public ImageLoader imageLoader;

String t;

public CustomArrayAdapter(Context context, String[] values,String[]img) {
    super(context, R.layout.activity_spec, values);
    this.context = context;
    this.values = values;
    this.img=img;
    imageLoader=new ImageLoader(getContext().getApplicationContext());
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    LayoutInflater inflater = (LayoutInflater) context
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    View rowView = inflater.inflate(R.layout.list_row, parent, false);
    TextView textView = (TextView) rowView.findViewById(R.id.title);
    ImageView imageView = (ImageView) rowView.findViewById(R.id.list_image);
    textView.setText(values[position]);

    // Change icon based on name
    String s = values[position];
//        System.out.println(t);
    //Log.d(t,img[position]);
    if(img==null){

    }else{

    int resourceId = context.getResources().getIdentifier(img[position],"drawable", context.getPackageName());
   // int drawableId = Integer.parseInt(img[position]);
        Bitmap bm;
      //  bm = Bitmap.createScaledBitmap(BitmapFactory.decodeFile(filepath),100, 100, true);
        //mPicture = new ImageView(context);
        //mPicture.setImageBitmap(bm);
        imageLoader.DisplayImage(resourceId, imageView);
    //imageView.setImageResource(resourceId);

            //img.recycle();
            //img = null;

    }
   /* if (s.equals("Lupetti")) {
        imageView.setImageResource(R.drawable.lupetti1);
    } else if (s.equals("Reparto")) {
        imageView.setImageResource(R.drawable.reparto1);
    } else if (s.equals("Clan")) {
        imageView.setImageResource(R.drawable.clan1);
    }
*/
    return rowView;
}
}

和:

public class ImageLoader {

MemoryCache memoryCache=new MemoryCache();
FileCache fileCache;
private Map<ImageView, String> imageViews=Collections.synchronizedMap(new WeakHashMap<ImageView, String>());
ExecutorService executorService; 

public ImageLoader(Context context){
    fileCache=new FileCache(context);
    executorService=Executors.newFixedThreadPool(5);
}

final int stub_id = R.drawable.ic_stub;
public void DisplayImage(int url, ImageView imageView)
{
    imageViews.put(imageView, "url");
    //Bitmap bitmap=memoryCache.get(url);
    if(url!=0)
        imageView.setImageResource(url);
    else
    {
        queuePhoto("url", imageView);
       imageView.setImageResource(stub_id);
    }
}

private void queuePhoto(String url, ImageView imageView)
{
    PhotoToLoad p=new PhotoToLoad(url, imageView);
    executorService.submit(new PhotosLoader(p));
}

private Bitmap getBitmap(String url) 
{
    File f=fileCache.getFile(url);

    //from SD cache
    Bitmap b = decodeFile(f);
    if(b!=null)
        return b;

    //from web
    try {
        Bitmap bitmap=null;
        URL imageUrl = new URL(url);
        HttpURLConnection conn = (HttpURLConnection)imageUrl.openConnection();
        conn.setConnectTimeout(30000);
        conn.setReadTimeout(30000);
        conn.setInstanceFollowRedirects(true);
        InputStream is=conn.getInputStream();
        OutputStream os = new FileOutputStream(f);
        Utils.CopyStream(is, os);
        os.close();
        bitmap = decodeFile(f);
        return bitmap;
    } catch (Exception ex){
       ex.printStackTrace();
       return null;
    }
}

//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);

        //Find the correct scale value. It should be the power of 2.
        final int REQUIRED_SIZE=70;
        int width_tmp=o.outWidth, height_tmp=o.outHeight;
        int scale=1;
        while(true){
            if(width_tmp/2<REQUIRED_SIZE || height_tmp/2<REQUIRED_SIZE)
                break;
            width_tmp/=2;
            height_tmp/=2;
            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;
}

//Task for the queue
private class PhotoToLoad
{
    public String url;
    public ImageView imageView;
    public PhotoToLoad(String u, ImageView i){
        url=u; 
        imageView=i;
    }
}

class PhotosLoader implements Runnable {
    PhotoToLoad photoToLoad;
    PhotosLoader(PhotoToLoad photoToLoad){
        this.photoToLoad=photoToLoad;
    }

    @Override
    public void run() {
        if(imageViewReused(photoToLoad))
            return;
        Bitmap bmp=getBitmap(photoToLoad.url);
        memoryCache.put(photoToLoad.url, bmp);
        if(imageViewReused(photoToLoad))
            return;
        BitmapDisplayer bd=new BitmapDisplayer(bmp, photoToLoad);
        Activity a=(Activity)photoToLoad.imageView.getContext();
        a.runOnUiThread(bd);
    }
}

boolean imageViewReused(PhotoToLoad photoToLoad){
    String tag=imageViews.get(photoToLoad.imageView);
    if(tag==null || !tag.equals(photoToLoad.url))
        return true;
    return false;
}

//Used to display bitmap in the UI thread
class BitmapDisplayer implements Runnable
{
    Bitmap bitmap;
    PhotoToLoad photoToLoad;
    public BitmapDisplayer(Bitmap b, PhotoToLoad p){bitmap=b;photoToLoad=p;}
    public void run()
    {
        if(imageViewReused(photoToLoad))
            return;
        if(bitmap!=null)
            photoToLoad.imageView.setImageBitmap(bitmap);
        else
            photoToLoad.imageView.setImageResource(stub_id);
    }
}

public void clearCache() {
    memoryCache.clear();
    fileCache.clear();
}

}

知道如何解决这个问题吗？谢谢!

Answer 1

android 中的位图可能存在很多问题，但首先你的适配器实现非常糟糕，你不会重复使用列表行，我敢肯定它很慢，这可能是你问题的根源。

您首先需要做的是阅读有关 convertView 模式的信息，使用它，然后告诉我们问题是否仍然存在。

更新:

首先，您不需要在每次调用 getView() 时都获取 LayoutInflater，您可以在适配器构造函数中设置它，然后重用它。

下一个 listView 有一种机制，可以只创建屏幕上可见的行数，当一行出现在屏幕上时，它会被重新使用。您需要做的是检查是否必须从头开始创建新行，或者重复使用现有行并用新数据填充它。

public class CustomArrayAdapter extends ArrayAdapter<String> {

    // Variable declarations
    LayoutInflater inflater;

    public CustomArrayAdapter(Context context, String[] values,String[]img) {
        // your code
        this.inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

         // convertView is null when new row is needed
         View rowView = convertView;

         if(rowView == null) {
             // new row is needed to inflate new row
             rowView = inflater.inflate(R.layout.list_row, parent, false);
         }


         TextView textView = (TextView) rowView.findViewById(R.id.title);
         ImageView imageView = (ImageView) rowView.findViewById(R.id.list_image);
         textView.setText(values[position]);

         // rest of your code
         return rowView;
     }
 }

当然你可以使用 Holder patter 做一些进一步的优化。

尝试实现所有这些，然后告诉我们您是否仍然遇到 OutOfMemory 错误