android - 位图压缩给出空文件(0 字节)

Question

编辑 - 另一个更新!

有趣的是，我在我的 nexus 5 上尝试了相同的代码，图像预览是正确的，但图像本身只是黑色。

正在使用的设备是s3 minis，在这些设备上无法打开图像并且不显示预览。

我的目标是 sdk 版本 16。

此外，我将我的 nexus 插回我的开发机器并作为存储设备打开，图像未显示。

然后我将手机中的图像通过电子邮件发送给自己，该死的东西显示正常，这让我更加困惑，我唯一能想到的是图像太大无法显示？

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我正在尝试创建一个图像，然后将其保存到文件中，它在屏幕上显示正常并且文件已创建，但是该文件无法打开并且大小为 0 字节。以前有人遇到过这个问题吗？这是我的代码:

private class SampleView extends View {


        public SampleView(Context context) {
            super(context);
            setFocusable(true);

        }
        @Override
        protected void onDraw(Canvas canvas) {

            EANMaker e = new EANMaker("123456789963");
            Paint paint = new Paint();
            View view = this;
            view.setDrawingCacheEnabled(true);
            view.setDrawingCacheQuality(view.DRAWING_CACHE_QUALITY_HIGH);

            canvas.drawColor(Color.WHITE);


            Bitmap b = Bitmap.createBitmap(500, 500, Bitmap.Config.ALPHA_8);
            Canvas c = new Canvas(b);
            c.drawRect(0, 0, 500, 500, paint);
            paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC));
            paint.setTextSize(40);
            paint.setTextScaleX(1.f);
            paint.setAlpha(0);
            paint.setAntiAlias(true);
            c.drawText("Carton ID", 60, 40, paint);
            paint.setTextSize(160);
            Typeface tf = gettypeFace(MyActivity.this, "ean.ttf");
            paint.setTypeface(tf);
            c.drawText(e.getCode(), 60, 180, paint);
            paint.setColor(Color.WHITE);
            canvas.drawBitmap(b, 50,50, paint);

            FileOutputStream fos = null;
            try {
                fos = new FileOutputStream(Environment.getExternalStorageDirectory().getAbsolutePath() + "/barcode.png");
                b.compress(Bitmap.CompressFormat.PNG, 100, fos);
                fos.flush();
                fos.close();
                fos = null;
            } catch (IOException ee) {
                ee.printStackTrace();
            } catch (Exception p)
            {
                p.printStackTrace();
            }
            finally {
                if (fos != null) {
                    try {
                        fos.close();
                    } catch (IOException ee) {
                        ee.printStackTrace();
                    }
                }
            }
        }

    }

    public Typeface gettypeFace(Context c, String assetPath) {
        synchronized (cache) {
            if (!cache.containsKey(assetPath)) {
                try {
                    Typeface t = Typeface.createFromAsset(c.getAssets(),
                            assetPath);
                    cache.put(assetPath, t);
                } catch (Exception e) {
                    Log.e("TAG", "Could not get typeface '" + assetPath
                            + "' because " + e.getMessage());
                    return null;
                }
            }
            return cache.get(assetPath);
        }
    }

编辑，我一直在玩这个，现在可以得到一个 6k 文件，但是仍然无法打开，我怀疑其中一个 Canvas 没有被绘制到位图中，但我完全不知道是什么还有事要做，我最新的代码如下

    private class SampleView extends View {


    public SampleView(Context context) {
        super(context);
        setFocusable(true);

    }
    @Override
    protected void onDraw(Canvas canvas) {


        EANMaker e = new EANMaker("123456789963");
        Paint paint = new Paint();
        canvas.drawColor(Color.WHITE);
        Bitmap b = Bitmap.createBitmap(900, 480, Bitmap.Config.ARGB_8888);
        Canvas c = new Canvas(b);
        canvas.drawBitmap(b,0,0, paint);

        //paint.setTextScaleX(1.f);

        paint.setColor(Color.BLACK);
        paint.setTextSize(40);
        c.drawText("Carton LABEL", 20, 40, paint);
        c.drawText("Carton ID = 1      Packed By = Test User", 20, 80, paint);
        c.drawText("Despatch Date = 05/08/2014", 20, 120, paint);
        paint.setTextSize(160);
        Typeface tf = gettypeFace(MyActivity.this, "ean.ttf");
        paint.setTypeface(tf);
        c.drawText(e.getCode(), 60, 280, paint);
        paint.setColor(Color.WHITE);


        FileOutputStream fos = null;
        try {
            fos = new FileOutputStream(Environment.getExternalStorageDirectory().getAbsolutePath() + "/barcode.png");
            b.compress(Bitmap.CompressFormat.PNG, 80, fos);
            fos.flush();
            fos.close();
            fos = null;
        } catch (IOException ee) {
            ee.printStackTrace();
        } catch (Exception p)
        {
            p.printStackTrace();
        }
        finally {
            if (fos != null) {
                try {
                    fos.close();
                } catch (IOException ee) {
                    ee.printStackTrace();
                }
            }
        }

    }

}

public Typeface gettypeFace(Context c, String assetPath) {
    synchronized (cache) {
        if (!cache.containsKey(assetPath)) {
            try {
                Typeface t = Typeface.createFromAsset(c.getAssets(),
                        assetPath);
                cache.put(assetPath, t);
            } catch (Exception e) {
                Log.e("TAG", "Could not get typeface '" + assetPath
                        + "' because " + e.getMessage());
                return null;
            }
        }
        return cache.get(assetPath);
    }
}

和我的 logcat 来证明没有错误:

08-05 13:13:02.371  26627-26627/com.example.imagetest I/System.out﹕ debugger has settled (1443)
08-05 13:13:03.082  26627-26627/com.example.imagetest D/libEGL﹕ loaded /system/lib/egl/libEGL_mali.so
08-05 13:13:03.082  26627-26627/com.example.imagetest D/libEGL﹕ loaded /system/lib/egl/libGLESv1_CM_mali.so
08-05 13:13:03.092  26627-26627/com.example.imagetest D/libEGL﹕ loaded /system/lib/egl/libGLESv2_mali.so
08-05 13:13:03.112  26627-26627/com.example.imagetest D/OpenGLRenderer﹕ Enabling debug mode 0
08-05 13:13:03.162  26627-26627/com.example.imagetest I/System.out﹕ Full code: 1234567899633
08-05 13:13:03.162  26627-26627/com.example.imagetest I/System.out﹕ Generated code: $!23E5GH-ijjgdd!
08-05 13:13:03.192  26627-26627/com.example.imagetest D/dalvikvm﹕ GC_FOR_ALLOC freed 84K, 13% free 9464K/10823K, paused 22ms, total 32ms
08-05 13:13:03.192  26627-26627/com.example.imagetest I/dalvikvm-heap﹕ Grow heap (frag case) to 12.093MB for 1728016-byte allocation
08-05 13:13:03.222  26627-26629/com.example.imagetest D/dalvikvm﹕ GC_CONCURRENT freed 39K, 12% free 11112K/12551K, paused 13ms+3ms, total 31ms
08-05 13:13:03.222  26627-26627/com.example.imagetest D/dalvikvm﹕ WAIT_FOR_CONCURRENT_GC blocked 9ms

Answer 1

正在创建图像，它们太大而无法在设备上正确打开。