我想设置一个特定的Drawable作为设备的壁纸,但所有的壁纸功能只接受位图。我不能使用WallpaperManager,因为我是pre 2.1。

另外,我的drawables是从网上下载的,并不存在于R.drawable中。


当前回答

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());
}

如何将可绘制的位读取为输入流的代码

其他回答

这将BitmapDrawable转换为Bitmap。

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

android-ktx有Drawable。toBitmap方法:https://android.github.io/android-ktx/core-ktx/androidx.graphics.drawable/android.graphics.drawable.-drawable/to-bitmap.html

从芬兰湾的科特林

val bitmap = myDrawable.toBitmap()

最新的androidx核心库(androidx.core:core-ktx:1.2.0)现在有一个扩展函数:Drawable. tobitmap(…)来将Drawable转换为Bitmap。

也许这能帮助到某人…

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; 
}

... 这样执行的:

Bitmap bmp = pictureDrawableToBitmap((PictureDrawable) drawable);

所以在看了(和使用)其他答案后,似乎他们都处理ColorDrawable和PaintDrawable很糟糕。(特别是在棒棒糖上)似乎着色器被调整了,所以固体块的颜色没有被正确处理。

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;
}

与其他方法不同,如果你在要求将Drawable转换为位图之前调用setBounds,它将以正确的大小绘制位图!