android - 如何更正此错误 : java. lang.OutOfMemoryError

Question

这是我的代码:

public void onPictureTaken(byte[] data, Camera camera) {
    Bitmap foto = BitmapFactory.decodeByteArray(data, 0, data.length);
    wid = foto.getWidth();
    hgt = foto.getHeight();

    Bitmap newImage = Bitmap.createBitmap(wid, hgt, Bitmap.Config.ARGB_4444);
    Canvas canvas = new Canvas(newImage);
    canvas.drawBitmap(foto, 0f, 0f, null);
    if (newImage.getWidth() > newImage.getHeight()) {
        Matrix matrix = new Matrix();
        matrix.postRotate(90);
        newImage.createBitmap(newImage, 0, 0, wid, hgt, matrix, true);

    }
}

这是我的错误:

FATAL EXCEPTION: main
java.lang.OutOfMemoryError
at android.graphics.Bitmap.nativeCreate(Native Method)
at android.graphics.Bitmap.createBitmap(Bitmap.java:689)
at android.graphics.Bitmap.createBitmap(Bitmap.java:666)
at android.graphics.Bitmap.createBitmap(Bitmap.java:633)
at com.supratecnologia.activity.Camera_Activity.onPictureTaken(Camera_Activity.java:189)
at android.hardware.Camera$EventHandler.handleMessage(Camera.java:768)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5041)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
at dalvik.system.NativeStart.main(Native Method)

Answer 1

大多数情况下，由于大位图超出了 VM 堆的限制，因此您需要缩小图像或降低图像质量。

要缩放图像，请使用 BitmapFactory.Options。

Bitmap bm = null;
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 5;
AssetFileDescriptor fileDescriptor =null;
try {
    fileDescriptor = this.getContentResolver().openAssetFileDescriptor(selectedImage,”r”);
} catch (FileNotFoundException e) {
    e.printStackTrace();
}
finally{
    try {
        bm = BitmapFactory.decodeFileDescriptor(fileDescriptor.getFileDescriptor(), null, options);
        fileDescriptor.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
} 

或者使用 Bitmap.compress() 来降低图像质量。

你也可以关注这个conversation避免在 Bitmap 中加载图像时出现内存错误。