Android WallpaperManager setBitmap fitCenter

Question

我正试着用WallpaperManager来给我手机的壁纸贴上一张位图。

• 图像大小:3840x2160
• 电话号码: 1080 x 1920

我尝试过很多策略：

1. myWallpaperManager.suggestDesiredDimensions(width，高度)；
2. Bitmap.createScaledBitmap(mImage，宽度，高度，真)；
3. Set Wallpaper with bitmap avoid crop and set fit center
4. how to fit the whole image on screen as wallpaper
5. Wallpaper not properly fit on device screen
6. https://developer.android.com/reference/android/app/WallpaperManager.html
7. answer.php?view=qad&token=39

每次我得到一个不适合中心的奇怪的位图，有人有什么建议吗？

我想要的是什么样子：

​

图像信息：

​

Answer 1

我找到了答案：Scaled Bitmap maintaining aspect ratio

我所做的是：

    DisplayMetrics metrics = new DisplayMetrics();
    getWindowManager().getDefaultDisplay().getMetrics(metrics);
    int phoneHeight = metrics.heightPixels;
    int phoneWidth = metrics.widthPixels;

    Bitmap mBit = returnBitmap(mImage, phoneWidth, phoneHeight);

private Bitmap returnBitmap(Bitmap originalImage, int width, int height){
    Bitmap background = Bitmap.createBitmap((int)width, (int)height, Bitmap.Config.ARGB_8888);

    float originalWidth = originalImage.getWidth();
    float originalHeight = originalImage.getHeight();

    Canvas canvas = new Canvas(background);

    float scale = width / originalWidth;

    float xTranslation = 0.0f;
    float yTranslation = (height - originalHeight * scale) / 2.0f;

    Matrix transformation = new Matrix();
    transformation.postTranslate(xTranslation, yTranslation);
    transformation.preScale(scale, scale);

    Paint paint = new Paint();
    paint.setFilterBitmap(true);

    canvas.drawBitmap(originalImage, transformation, paint);

    return background;
}