android - 位图大小超过 32 位

Question

我正在使用搜索栏缩放位图。每当我增加搜索栏的进度时，图像缩放都会因出现错误“位图大小超过 32 位”而失败。如果我使用默认搜索栏值缩放图像。它给出错误“非法参数异常:宽度和高度必须 > 0”。

日志报告

07-26 05:20:23.189: E/AndroidRuntime(1145): FATAL EXCEPTION: main
07-26 05:20:23.189: E/AndroidRuntime(1145): java.lang.IllegalArgumentException: bitmap size exceeds 32bits
07-26 05:20:23.189: E/AndroidRuntime(1145):     at android.graphics.Bitmap.nativeCreate(Native Method)
07-26 05:20:23.189: E/AndroidRuntime(1145):     at android.graphics.Bitmap.createBitmap(Bitmap.java:697)
07-26 05:20:23.189: E/AndroidRuntime(1145):     at android.graphics.Bitmap.createBitmap(Bitmap.java:674)
07-26 05:20:23.189: E/AndroidRuntime(1145):     at android.graphics.Bitmap.createBitmap(Bitmap.java:607)
07-26 05:20:23.189: E/AndroidRuntime(1145):     at com.example.navigationexample.QRCodeGenerator.scaleImage(QRCodeGenerator.java:127)
07-26 05:20:23.189: E/AndroidRuntime(1145):     at com.example.navigationexample.MainActivity$3.onClick(MainActivity.java:356)
07-26 05:20:23.189: E/AndroidRuntime(1145):     at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:166)
07-26 05:20:23.189: E/AndroidRuntime(1145):     at android.os.Handler.dispatchMessage(Handler.java:99)
07-26 05:20:23.189: E/AndroidRuntime(1145):     at android.os.Looper.loop(Looper.java:137)
07-26 05:20:23.189: E/AndroidRuntime(1145):     at android.app.ActivityThread.main(ActivityThread.java:5103)
07-26 05:20:23.189: E/AndroidRuntime(1145):     at java.lang.reflect.Method.invokeNative(Native Method)
07-26 05:20:23.189: E/AndroidRuntime(1145):     at java.lang.reflect.Method.invoke(Method.java:525)
07-26 05:20:23.189: E/AndroidRuntime(1145):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
07-26 05:20:23.189: E/AndroidRuntime(1145):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
07-26 05:20:23.189: E/AndroidRuntime(1145):     at dalvik.system.NativeStart.main(Native Method)
07-26 05:20:25.857: I/Process(1145): Sending signal. PID: 1145 SIG: 9

代码 fragment

public void showSaveDialog() {

    LayoutInflater inflater = getLayoutInflater();
    dialog = null;

    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle("Save QR Image");

    View v = inflater.inflate(R.layout.save_dialog, null);
    builder.setView(v);

    final EditText et = (EditText) v.findViewById(R.id.qrName);
    et.setMaxLines(1);

    final TextView widthText = (TextView) v.findViewById(R.id.widthSize);
    final TextView heightText = (TextView) v.findViewById(R.id.heightSize);

    SeekBar seekBar = (SeekBar) v.findViewById(R.id.seekBar1);

    seekBar.setMax(16);

    // To set minimum value of seekbar
    seekMin = seekBar.getProgress();
    if (seekMin < 128) {
        seekBar.setProgress(1);
        widthText.setText("128");
        heightText.setText("128");
    }

    seekBar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {

        @Override
        public void onStopTrackingTouch(SeekBar arg0) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onStartTrackingTouch(SeekBar arg0) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onProgressChanged(SeekBar seekBar, int progresValue,
                boolean fromUser) {
            // TODO Auto-generated method stub
            val = progresValue * 128;
            String size = String.valueOf(val);
            widthText.setText(size);
            heightText.setText(size);
        }
    });

    builder.setPositiveButton("Save", new OnClickListener() {

        @Override
        public void onClick(DialogInterface arg0, int arg1) {
            // TODO Auto-generated method stub
            qrName = et.getText().toString();

            if (qrName.isEmpty()) {
                Toast.makeText(getApplicationContext(),
                        "Please enter name", Toast.LENGTH_SHORT).show();
            } else {

                Bitmap sImg = classB.scaleImage(image, val, density);
                saveImage(sImg);
            }
        }
    });
    dialog = builder.create();
    dialog.show();
}

B类图像缩放函数

public Bitmap scaleImage(Bitmap bitmap, int bound, int density) {

    int w = bitmap.getWidth();
    int h = bitmap.getHeight();

    // Get current dimensions AND the desired bounding box
    int bounding = dpToPx(bound, density);
    Log.i("Test", "original width = " + Integer.toString(w));
    Log.i("Test", "original height = " + Integer.toString(h));
    Log.i("Test", "bounding = " + Integer.toString(bounding));

    // Determine how much to scale: the dimension requiring less scaling is
    // closer to the its side. This way the image always stays inside your
    // bounding box AND either x/y axis touches it.
    float xScale = ((float) bounding) / w;
    float yScale = ((float) bounding) / h;
    float scale = (xScale <= yScale) ? xScale : yScale;
    Log.i("Test", "xScale = " + Float.toString(xScale));
    Log.i("Test", "yScale = " + Float.toString(yScale));
    Log.i("Test", "scale = " + Float.toString(scale));

    // Create a matrix for the scaling and add the scaling data
    Matrix matrix = new Matrix();
    matrix.postScale(scale, scale);

    // Create a new bitmap and convert it to a format understood by the
    // ImageView
    Bitmap scaledBitmap = Bitmap.createBitmap(bitmap, 0, 0, w, h, matrix,
            true);
    sWidth = scaledBitmap.getWidth(); // re-use
    sHeight = scaledBitmap.getHeight(); // re-use
    @SuppressWarnings("deprecation")
    BitmapDrawable result = new BitmapDrawable(scaledBitmap);
    Log.i("Test", "scaled width = " + Integer.toString(sWidth));
    Log.i("Test", "scaled height = " + Integer.toString(sHeight));

    return scaledBitmap;
}

scaleImage() 函数中获取边界值的函数

private int dpToPx(int dp, int density) {
    int result = Math.round((float) dp * density);
    return result;
}

Answer 1

您将哪个值传递给 dpToPx(int,int) 方法的 density 参数？

您的方法将密度声明为 int，这让我相信您可能传入了 DisplayMetrics.densityDpi，一个三位数的 int数字。您打算使用 DisplayMetrics.density，单个数字 float 数字。这会将您的图像尺寸推到 32 位之外:

threshold 32 bits signed int = 2^31 -1         =  2147483647

progressValue = 16
bitmap edge   = 16 * 128     = 2048
bitmap size   = 2048^2       = 4194304
at 32 bpp     = 4194304 * 32 = 134217728

multiplied by densityDpi     = 134217728 * 460 = 61740154880  // kaboom
multiplied by density        = 134217728 * 3   =   402653184  // ok