内存异常，同时滚动列表视图？ [英] Out of Memory Exception while scroll Listview?

问题描述

我refered经历了许多资源，但无法得到正确的答案，

I refered through many resources but can't get right answer,

我做了一个自定义的适配器的列表视图查看图像。这个图像被检索到的存储卡。一切都正常运行，但是当我通过列表视图滚动我得到一个内存不足的异常。我已经张贴了code。使用我retrive图像从SD卡。

I have made an custom adapter to view images in a listview. This images are retrieved from memory card. Everything runs fine but while i scroll through the listview i get an OutOfMemory Exception. I have posting the code using which i retrive images from sdcard.

public void getFromSdcard() {

    File file = new File(
            android.os.Environment.getExternalStorageDirectory(),
            "Tiles/.NoMedia");

    if (file.isDirectory()) {
        listFile = file.listFiles();

        for (int i = 0; i < listFile.length; i++) {

            f.add(listFile[i].getAbsolutePath());

        }
    }
}

这里f是字符串数组列表，我将其传递给下一个自定义适配器是$ C $下我自定义的适配器。

here f is arraylist of string and i am passing it to an custom adapter following is the code for my custom adapter.

public class NewImageAdapter extends ArrayAdapter<Image> {

private ArrayList<Image> objects;
String packageName;
Activity act;

public NewImageAdapter(Activity context, int image_layout,
        ArrayList<Image> objects) {
    super(context, image_layout, objects);
    this.act = context;
    this.objects = objects;

}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub

    View v = convertView;

    if (v == null) {
        LayoutInflater inflater = (LayoutInflater) getContext()
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        v = inflater.inflate(R.layout.list_item, null);
    }

    Image i = objects.get(position);

    if (i != null) {
        ImageView iv = (ImageView) v.findViewById(R.id.imagemenu123);
        // TextView tv = (TextView) v.findViewById(R.id.commandText);
        if (iv != null) {

            Bitmap myBitmap = BitmapFactory.decodeFile(i.getImagePath());

            iv.setImageBitmap(myBitmap);
            // iv.setImageBitmap(i.getImageBitmap());
            // tv.setText("Tiles Images");
        }

    }
    return v;
}

}

任何解决我的问题：

推荐答案

使用这个概念，这将帮助你，在这之后设置图像视图的imagebitmap

use this concept this will help you, After that set the imagebitmap on image view

public static Bitmap convertBitmap(String path)   {

        Bitmap bitmap=null;
        BitmapFactory.Options bfOptions=new BitmapFactory.Options();
        bfOptions.inDither=false;                     //Disable Dithering mode
        bfOptions.inPurgeable=true;                   //Tell to gc that whether it needs free memory, the Bitmap can be cleared
        bfOptions.inInputShareable=true;              //Which kind of reference will be used to recover the Bitmap data after being clear, when it will be used in the future
        bfOptions.inTempStorage=new byte[32 * 1024]; 


        File file=new File(path);
        FileInputStream fs=null;
        try {
            fs = new FileInputStream(file);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }

        try {
            if(fs!=null)
            {
                bitmap=BitmapFactory.decodeFileDescriptor(fs.getFD(), null, bfOptions);
            }
            } catch (IOException e) {

            e.printStackTrace();
        } finally{ 
            if(fs!=null) {
                try {
                    fs.close();
                } catch (IOException e) {

                    e.printStackTrace();
                }
            }
        }

        return bitmap;
    }

如果你想从大的图像高度和宽度像60和60的小图像，然后滚动列表视图快速然后用这个概念

If you want to make a small image from large image with height and width like 60 and 60 and scroll the listview fast then use this concept

public static Bitmap decodeSampledBitmapFromPath(String path, int reqWidth,
            int reqHeight) {

        final BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(path, options);

        options.inSampleSize = calculateInSampleSize(options, reqWidth,
                reqHeight);

        // Decode bitmap with inSampleSize set
        options.inJustDecodeBounds = false;
        Bitmap bmp = BitmapFactory.decodeFile(path, options);
        return bmp;
        }

    public static int calculateInSampleSize(BitmapFactory.Options options,
            int reqWidth, int reqHeight) {

        final int height = options.outHeight;
        final int width = options.outWidth;
        int inSampleSize = 1;

        if (height > reqHeight || width > reqWidth) {
            if (width > height) {
                inSampleSize = Math.round((float) height / (float) reqHeight);
            } else {
                inSampleSize = Math.round((float) width / (float) reqWidth);
             }
         }
         return inSampleSize;
        }

我希望它会帮助你了。

I hope it will help you much.

您凸轮采取由开发者网站 这里

You cam take help from developer site Here

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