Question

我想创建一个用户可以设置背景的活动。不幸的是，当我加载大约7张图像时，图像太大了＃39; 它抛出一个异常（Failed to allocate a 74649612 byte allocation with 7804240 free bytes and 7MB until OOM）。有没有办法让图像更小？＆＃39;在Android Studio中，没有在photoshop中缩小它？

    @Override
    protected void onCreate(Bundle savedInstanceState) {
    (...)
    ImageView image_1 = (ImageView) findViewById(R.id.image_1);
    ImageView image_2 = (ImageView) findViewById(R.id.image_2);
    ...

    image_1.setImageDrawable(getDrawable(R.drawable.background_1));
    image_2.setImageDrawable(getDrawable(R.drawable.background_2));
    ...

我在AndroidManifest.xml中启用了android:largeHeap="true"。

感谢您的帮助。

Answer 1

我认为这可以帮助你。

Handling Bitmaps

或者您可以使用Glide Library。

Answer 2

您可以通过减小可绘制图像的大小来解决此问题，为此您需要先将图像转换为位图，然后使用以下代码来减小位图的大小

  public static Bitmap makeBitmap(String fn, int minSideLength, int maxNumOfPixels) {
BitmapFactory.Options options;
try {
    options = new BitmapFactory.Options();

    options.inPurgeable = true;
    options.inJustDecodeBounds = true;
    BitmapFactory.BitmapFactory.decodeResource(getResources(), R.drawable.large_icon,options);
    if (options.mCancel || options.outWidth == -1
            || options.outHeight == -1) {
        return null;
    }
    options.inSampleSize = computeSampleSize(
            options, minSideLength, maxNumOfPixels);
    options.inJustDecodeBounds = false;
    //Log.e(LOG_TAG, "sample size=" + options.inSampleSize);

    options.inDither = false;
    options.inPreferredConfig = Bitmap.Config.ARGB_8888;
    return BitmapFactory.decodeFile(fn, options);
} catch (OutOfMemoryError ex) {
    Log.e(LOG_TAG, "Got oom exception ", ex);
    return null;
}
}

private static int computeInitialSampleSize(BitmapFactory.Options options,
    int minSideLength, int maxNumOfPixels) {
double w = options.outWidth;
double h = options.outHeight;

int lowerBound = (maxNumOfPixels == UNCONSTRAINED) ? 1 :
        (int) Math.ceil(Math.sqrt(w * h / maxNumOfPixels));
int upperBound = (minSideLength == UNCONSTRAINED) ? 128 :
        (int) Math.min(Math.floor(w / minSideLength),
        Math.floor(h / minSideLength));

if (upperBound < lowerBound) {
    // return the larger one when there is no overlapping zone.
    return lowerBound;
}

if ((maxNumOfPixels == UNCONSTRAINED) &&
        (minSideLength == UNCONSTRAINED)) {
    return 1;
} else if (minSideLength == UNCONSTRAINED) {
    return lowerBound;
} else {
    return upperBound;
}
}

Answer 3

您可以使用Glide加载图像并缩小图像。您可以在Gradle文件中添加它：

repositories {
  mavenCentral() // jcenter() works as well because it pulls from Maven Central
}

dependencies {
  compile 'com.github.bumptech.glide:glide:3.7.0'
  compile 'com.android.support:support-v4:25.3.1'
  annotationProcessor 'com.github.bumptech.glide:compiler:4.0.0-RC1'
}

这可能是一种如何使用它的方法：

Glide.with(context)
            .load(images.get(position))
            .override((int)(thumbnailHeight * IMAGE_SCALE_FACTOR), (int)(thumbnailHeight * IMAGE_SCALE_FACTOR))
            .into(imageView);

其中images是包含图片网址（本地或远程）的ArrayList<String>，thumbnailHeight是包含此图片的视图的高度（我还使用了宽度的高度值）使其平方），IMAGE_SCALE_FACTOR是一个常数，表示你的图像缩小了多少（如果你想要它缩小，只需使用0.1到0.9之间的值）

如何显示许多图像？

3 个答案: