Question

我实际上是在方法中得到这个错误在里面加载图像我正在做我将选项大小设置为：

bmOptions.inSampleSize = 1;

错误指向行decodeStream() ..

的方法

private Bitmap LoadImage(String URL, BitmapFactory.Options options) {
        Bitmap bitmap = null;
        InputStream in = null;
        try {
            in = OpenHttpConnection(URL);
            bitmap = BitmapFactory.decodeStream(in, null, options);
            in.close();

        } catch (IOException e1) {

            return null;
        }
        return bitmap;

    }

E/dalvikvm-heap(8627): Out of memory on a 3001616-byte allocation.
at decodeStream()
at loadImage()

Answer 1

以下是将文件解码为指定比例的代码。

    File f = new File(StringfileName);
    Bitmap bm = decodeFile(f);

    private static 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 = 150;

        // 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;
        o.inJustDecodeBounds = false;
        return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
    } catch (FileNotFoundException e) {
    }

    return null;
}

Answer 2

这个类以高效的方式将图像缩放到精确的大小，它也会进行一些自动旋转，你可能想要禁用它或传递角度。基于帖子：http://zerocredibility.wordpress.com/2011/01/27/android-bitmap-scaling/

import java.io.IOException;

import java.io.InputStream;

import android.content.ContentResolver;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.net.Uri;

/**
 * http://zerocredibility.wordpress.com/2011/01/27/android-bitmap-scaling/
 * 
 */
public final class 

BitmapScaler {

    /**
     * 
     * @param uri
     * @param context
     * @param newWidth
     *            Image will not exceed this width
     * @param newHeight
     *            Image will not exceed this height
     * @return
     * @throws IOException
     */
    public static Bitmap ScaleBitmap(Uri uri, Context context,
            int newWidth, int newHeight, int targetWidth, int targetHeight)
            throws IOException {
        final ContentResolver contentResolver = context.getContentResolver();
        int sample = 1;
        {
            InputStream is = contentResolver.openInputStream(uri);
            try {
                sample = getRoughSize(is, newWidth, newHeight);
            } finally {
                is.close();
            }
        }
        {
            InputStream is = contentResolver.openInputStream(uri);
            try {
                Bitmap temp = roughScaleImage(is, sample);
                try {
                    return scaleImage(temp, newWidth, newHeight, targetWidth,
                            targetHeight);
                } finally {
                    temp.recycle();
                }
            } finally {
                is.close();
            }
        }
    }

    private static Bitmap scaleImage(final Bitmap source, final int maxWidth,
            final int maxHeight, final int targetWidth, final int targetHeight) {

        int newWidth = maxWidth;
        int newHeight = maxHeight;

        final int sourceHeight = source.getHeight();
        final int sourceWidth = source.getWidth();
        final int angle = sourceHeight > sourceWidth ? -90 : 0;
        final boolean rotate = angle != 0;
        final boolean nintey = (angle == 90) || (angle == -90);
        final int width = nintey ? sourceHeight : sourceWidth;
        final int height = nintey ? sourceWidth : sourceHeight;

        final float scaleByWidth = ((float) newWidth / width);
        int testNewHeight = (int) (height * scaleByWidth);

        float scale;

        if (testNewHeight > newHeight) { // then we must scale to match
                                            // newHeight instead of new width
            final float scaleByHeight = ((float) newHeight / height);
            newWidth = (int) (width * scaleByHeight);
            scale = scaleByHeight;
        } else {
            // accept the scale
            newHeight = testNewHeight;
            scale = scaleByWidth;
        }

        Matrix matrix = new Matrix();
        matrix.postScale(scale, scale);
        if (rotate) {
            matrix.postRotate(angle);
            matrix.postTranslate(0, newHeight);
        }
        matrix.postTranslate((maxWidth - newWidth) / 2,
                (maxHeight - newHeight) / 2);

        Bitmap b = Bitmap.createBitmap(targetWidth, targetHeight,
                Bitmap.Config.ARGB_8888);
        Paint p = new Paint(Paint.FILTER_BITMAP_FLAG);
        Canvas c = new Canvas(b);
        c.drawBitmap(source, matrix, p);
        return b;
    }

    private static Bitmap roughScaleImage(InputStream is, int sample) {
        BitmapFactory.Options scaledOpts = new BitmapFactory.Options();
        scaledOpts.inSampleSize = sample;
        return BitmapFactory.decodeStream(is, null, scaledOpts);
    }

    private static int getRoughSize(InputStream is, int newWidth, int newHeight) {
        BitmapFactory.Options o = new BitmapFactory.Options();
        o.inJustDecodeBounds = true;
        BitmapFactory.decodeStream(is, null, o);

        return getRoughSize(o.outWidth, o.outHeight, newWidth, newHeight);
    }

    private static int getRoughSize(int width, int height, int newWidth,
            int newHeight) {
        int sample = 1;

        while (true) {
            if (width / 2 < newWidth || height / 2 < newHeight) {
                break;
            }
            width /= 2;
            height /= 2;
            sample *= 2;
        }
        return sample;
    }
}

Answer 3

看一下这篇文档http://developer.android.com/training/displaying-bitmaps/load-bitmap.html。我之前也遇到过同样的问题。

位图解码的3001616字节分配错误导致内存不足

3 个答案: