提问



我想设置一个Drawable作为设备的壁纸,但所有壁纸功能只接受Bitmap s。我不能使用WallpaperManager,因为我预先2.1。


此外,我的drawables是从网上下载的,不在R.drawable中。

最佳参考


这段代码有帮助。


Bitmap icon = BitmapFactory.decodeResource(context.getResources(),
                                           R.drawable.icon_resource);


这是一个下载图像的版本。


String name = c.getString(str_url);
URL url_value = new URL(name);
ImageView profile = (ImageView)v.findViewById(R.id.vdo_icon);
if (profile != null) {
    Bitmap mIcon1 =
        BitmapFactory.decodeStream(url_value.openConnection().getInputStream());
    profile.setImageBitmap(mIcon1);
}

其它参考1


public static Bitmap drawableToBitmap (Drawable drawable) {
    Bitmap bitmap = null;

    if (drawable instanceof BitmapDrawable) {
        BitmapDrawable bitmapDrawable = (BitmapDrawable) drawable;
        if(bitmapDrawable.getBitmap() != null) {
            return bitmapDrawable.getBitmap();
        }
    }

    if(drawable.getIntrinsicWidth() <= 0 || drawable.getIntrinsicHeight() <= 0) {
        bitmap = Bitmap.createBitmap(1, 1, Bitmap.Config.ARGB_8888); // Single color bitmap will be created of 1x1 pixel
    } else {
        bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
    }

    Canvas canvas = new Canvas(bitmap);
    drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
    drawable.draw(canvas);
    return bitmap;
}

其它参考2


这会将BitmapDrawable转换为Bitmap。


Drawable d = ImagesArrayList.get(0);  
Bitmap bitmap = ((BitmapDrawable)d).getBitmap();

其它参考3


A Drawable可以绘制在Canvas上,Canvas可以由Bitmap支持:


(已更新以处理BitmapDrawable的快速转换并确保创建的Bitmap具有有效大小)


public static Bitmap drawableToBitmap (Drawable drawable) {
    if (drawable instanceof BitmapDrawable) {
        return ((BitmapDrawable)drawable).getBitmap();
    }

    int width = drawable.getIntrinsicWidth();
    width = width > 0 ? width : 1;
    int height = drawable.getIntrinsicHeight();
    height = height > 0 ? height : 1;

    Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap); 
    drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
    drawable.draw(canvas);

    return bitmap;
}

其它参考4


使用此代码:


Bitmap bitmap= BitmapFactory.decodeResource(context.getResources(), 
    R.drawable.icon_name);

其它参考5


很简单


Bitmap tempBMP = BitmapFactory.decodeResource(getResources(),R.drawable.image);

其它参考6


方法1 :您可以直接转换为这样的位图


Bitmap myLogo = BitmapFactory.decodeResource(context.getResources(), R.drawable.my_drawable);


方法2 :您甚至可以将资源转换为drawable,从中可以获得这样的位图


Bitmap myLogo = ((BitmapDrawable)getResources().getDrawable(R.drawable.logo)).getBitmap();


对于API> 22 getDrawable方法移动到ResourcesCompat类,所以你做这样的事情


Bitmap myLogo = ((BitmapDrawable) ResourcesCompat.getDrawable(context.getResources(), R.drawable.logo, null)).getBitmap();

其它参考7


也许这会帮助别人......


从PictureDrawable到Bitmap,使用:


private Bitmap pictureDrawableToBitmap(PictureDrawable pictureDrawable){ 
    Bitmap bmp = Bitmap.createBitmap(pictureDrawable.getIntrinsicWidth(), pictureDrawable.getIntrinsicHeight(), Config.ARGB_8888); 
    Canvas canvas = new Canvas(bmp); 
    canvas.drawPicture(pictureDrawable.getPicture()); 
    return bmp; 
}


......如此实施:


Bitmap bmp = pictureDrawableToBitmap((PictureDrawable) drawable);

其它参考8


因此,在查看(和使用)其他答案后,似乎他们都严重处理ColorDrawablePaintDrawable。 (特别是在棒棒糖上)似乎Shader被调整,因此没有正确处理固体颜色块。


我现在使用以下代码:


public static Bitmap drawableToBitmap(Drawable drawable) {
    if (drawable instanceof BitmapDrawable) {
        return ((BitmapDrawable) drawable).getBitmap();
    }

    // We ask for the bounds if they have been set as they would be most
    // correct, then we check we are  > 0
    final int width = !drawable.getBounds().isEmpty() ?
            drawable.getBounds().width() : drawable.getIntrinsicWidth();

    final int height = !drawable.getBounds().isEmpty() ?
            drawable.getBounds().height() : drawable.getIntrinsicHeight();

    // Now we check we are > 0
    final Bitmap bitmap = Bitmap.createBitmap(width <= 0 ? 1 : width, height <= 0 ? 1 : height,
            Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap);
    drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
    drawable.draw(canvas);

    return bitmap;
}


与其他人不同,如果在要求将其转换为位图之前在Drawable上调用setBounds,它将以正确的大小绘制位图!

其它参考9


这是更好的分辨率


public static Bitmap drawableToBitmap (Drawable drawable) {
    if (drawable instanceof BitmapDrawable) {
        return ((BitmapDrawable)drawable).getBitmap();
    }

    Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap); 
    drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
    drawable.draw(canvas);

    return bitmap;
}

public static InputStream bitmapToInputStream(Bitmap bitmap) {
    int size = bitmap.getHeight() * bitmap.getRowBytes();
    ByteBuffer buffer = ByteBuffer.allocate(size);
    bitmap.copyPixelsToBuffer(buffer);
    return new ByteArrayInputStream(buffer.array());
}


代码来自如何将可绘制位读取为InputStream

其它参考10


Android提供了一个非直接的解决方案:BitmapDrawable。为了获得位图,我们必须向a BitmapDrawable提供资源ID R.drawable.flower_pic,然后将其转换为Bitmap


Bitmap bm = ((BitmapDrawable) getResources().getDrawable(R.drawable.flower_pic)).getBitmap();

其它参考11


以下是@ Chris.Jenkins提供的答案的好Kotlin版本:https://stackoverflow.com/a/27543712/1016462


fun Drawable.toBitmap(): Bitmap {
  if (this is BitmapDrawable) {
    return bitmap
  }

  val width = if (bounds.isEmpty) intrinsicWidth else bounds.width()
  val height = if (bounds.isEmpty) intrinsicHeight else bounds.height()

  return Bitmap.createBitmap(width.nonZero(), height.nonZero(), Bitmap.Config.ARGB_8888).also {
    val canvas = Canvas(it)
    setBounds(0, 0, canvas.width, canvas.height)
    draw(canvas)
  }
}

private fun Int.nonZero() = if (this <= 0) 1 else this

其它参考12


使用此代码。它将帮助您实现目标。


 Bitmap bmp=BitmapFactory.decodeResource(getResources(), R.drawable.profileimage);
    if (bmp!=null) {
        Bitmap bitmap_round=getRoundedShape(bmp);
        if (bitmap_round!=null) {
            profileimage.setImageBitmap(bitmap_round);
        }
    }

  public Bitmap getRoundedShape(Bitmap scaleBitmapImage) {
    int targetWidth = 100;
    int targetHeight = 100;
    Bitmap targetBitmap = Bitmap.createBitmap(targetWidth, 
            targetHeight,Bitmap.Config.ARGB_8888);

    Canvas canvas = new Canvas(targetBitmap);
    Path path = new Path();
    path.addCircle(((float) targetWidth - 1) / 2,
            ((float) targetHeight - 1) / 2,
            (Math.min(((float) targetWidth), 
                    ((float) targetHeight)) / 2),
                    Path.Direction.CCW);

    canvas.clipPath(path);
    Bitmap sourceBitmap = scaleBitmapImage;
    canvas.drawBitmap(sourceBitmap, 
            new Rect(0, 0, sourceBitmap.getWidth(),
                    sourceBitmap.getHeight()), 
                    new Rect(0, 0, targetWidth, targetHeight), new Paint(Paint.FILTER_BITMAP_FLAG));
    return targetBitmap;
}

其它参考13


 // get image path from gallery
protected void onActivityResult(int requestCode, int resultcode, Intent intent) {
    super.onActivityResult(requestCode, resultcode, intent);

    if (requestCode == 1) {
        if (intent != null && resultcode == RESULT_OK) {             
            Uri selectedImage = intent.getData();

            String[] filePathColumn = {MediaStore.Images.Media.DATA};
            Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);
            cursor.moveToFirst();
            int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
            filePath = cursor.getString(columnIndex);

            //display image using BitmapFactory

            cursor.close(); bmp = BitmapFactory.decodeFile(filepath); 
            iv.setBackgroundResource(0);
            iv.setImageBitmap(bmp);
        }
    }
}