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How to convert a Drawable to a Bitmap?

如何解决《HowtoconvertaDrawabletoaBitmap?》经验,为你挑选了12个好方法。

I would like to set a certain Drawable as the device's wallpaper, but all wallpaper functions accept Bitmaps only. I cannot use WallpaperManager because I'm pre 2.1.

Also, my drawables are downloaded from the web and do not reside in R.drawable.



1> Praveen..:

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);
}


我想我找到了一些东西:如果"draw"是drawable我想转换成位图然后:Bitmap bitmap =((BitmapDrawable)draw).getBitmap(); 诀窍!
注意:这会导致带有JPG的大量java.lang.OutOfMemoryError

2> André..:
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;
}


这看起来是唯一适用于任何类型的drawable的答案,并且还有一个已经是BitmapDrawable的drawable的快速解决方案.+1
注意:如果drawable是纯色,`getIntrinsicWidth()`和`getIntrinsicHieght()`将返回-1.
所以...再次检查ColorDrawable,我们有一个胜利者.说真的,有人认为这是公认的答案.
与标记的答案相反,这回答了问题.

3> Rob..:

这会将BitmapDrawable转换为Bitmap.

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


不敢相信这64个赞成票吗?那个代码显然只有在`d`已经*是一个'BitmapDrawable`时才有效,在这种情况下,将它作为位图检索是微不足道的......在所有其他情况下,它会与`ClassCastException`崩溃.
这真的是最好的方式吗?当然drawable可能是另一种类型,这会抛出runtimeException吗?例如,它可能是一个9PatchDrawble ......?
@Dori你可以在一个条件语句中包装代码,以检查它是否确实是一个`BitmapDrawable`在投之前:`if(d instanceof BitmapDrawable){Bitmap bitmap =((BitmapDrawable)d).getBitmap(); }`
@Matthias更不用说..问题本身,同一作者,有100票:/
这是一个专门针对一个微不足道的案例.
对于那些抱怨这是错误的人,你们有没有检查过关于页面的SO?它说接受的答案并不一定意味着答案是正确的,这意味着答案适用于OP.
惊喜是:当评论得到更多的投票而不是回答本身.

4> kabuko..:

A Drawable可以绘制到a Canvas,并且Canvas可以由以下内容支持Bitmap:

(已更新以处理BitmapDrawables 的快速转换并确保Bitmap创建的有效大小)

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;
}



5> Keyur Lakhan..:

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();



6> Erfan Bagher..:

非常简单

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


这只是整整三年前对这个问题的[其他答案](http://stackoverflow.com/a/3035869/984830)的抄袭

7> Chris.Jenkin..:

所以其他的答案中寻找(并使用)之后,他们似乎都处理ColorDrawablePaintDrawable严重.(特别是在棒棒糖上)似乎Shaders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;
}

不像其他人,如果你拨打setBoundsDrawable要求把它变成一个位图前,将以此为位图以正确的尺寸!



8> Mauro..:

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);


"也许这会帮助别人......"

9> Dawid Drozd..:

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



10> tasomaniac..:

这是@ Chris.Jenkins在这里提供的答案的好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



11> kc ochibili..:

Android提供了一个非直接的解决方案:BitmapDrawable.为了得到位图,我们必须提供的资源ID R.drawable.flower_pic的一个BitmapDrawable,然后将其转换为Bitmap.

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



12> 小智..:

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;
}

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