Android 如何将 Drawable 转换为位图？
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How to convert a Drawable to a Bitmap?
提问by Rob
I would like to set a certain Drawableas the device's wallpaper, but all wallpaper functions accept Bitmaps only. I cannot use WallpaperManagerbecause I'm pre 2.1.
我想设置某个Drawable作为设备的壁纸，但所有壁纸功能Bitmap只接受s。我无法使用，WallpaperManager因为我是 2.1 之前的版本。
Also, my drawables are downloaded from the web and do not reside in R.drawable.
另外，我的 drawables 是从网上下载的，不存在于R.drawable.
采纳答案by Rob
This converts a BitmapDrawable to a Bitmap.
这会将 BitmapDrawable 转换为 Bitmap。
Drawable d = ImagesArrayList.get(0);
Bitmap bitmap = ((BitmapDrawable)d).getBitmap();
回答by Praveen
This piece of code helps.
这段代码有帮助。
Bitmap icon = BitmapFactory.decodeResource(context.getResources(),
R.drawable.icon_resource);
Here a version where the image gets downloaded.
这是下载图像的版本。
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);
}
回答by 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;
}
回答by kabuko
A Drawablecan be drawn onto a Canvas, and a Canvascan be backed by a Bitmap:
ADrawable可以绘制到 a 上Canvas，并且 aCanvas可以由 a 支持Bitmap：
(Updated to handle a quick conversion for BitmapDrawables and to ensure that the Bitmapcreated has a valid size)
（更新以处理BitmapDrawables的快速转换并确保Bitmap创建的具有有效大小）
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;
}
回答by Keyur
METHOD 1: Either you can directly convert to bitmap like this
方法1：您可以像这样直接转换为位图
Bitmap myLogo = BitmapFactory.decodeResource(context.getResources(), R.drawable.my_drawable);
METHOD 2: You can even convert the resource into the drawable and from that you can get bitmap like this
方法 2：您甚至可以将资源转换为可绘制对象，从中您可以获得像这样的位图
Bitmap myLogo = ((BitmapDrawable)getResources().getDrawable(R.drawable.logo)).getBitmap();
For API > 22getDrawablemethod moved to the ResourcesCompatclass so for that you do something like this
对于API > 22getDrawable方法移动到ResourcesCompat类中，因此您可以执行以下操作
Bitmap myLogo = ((BitmapDrawable) ResourcesCompat.getDrawable(context.getResources(), R.drawable.logo, null)).getBitmap();
回答by Erfan Bagheri
very simple
很简单
Bitmap tempBMP = BitmapFactory.decodeResource(getResources(),R.drawable.image);
回答by Chris.Jenkins
So after looking (and using) of the other answers, seems they all handling ColorDrawableand PaintDrawablebadly. (Especially on lollipop) seemed that Shaders were tweaked so solid blocks of colors were not handled correctly.
所以其他的答案中寻找（并使用）之后，他们似乎都处理ColorDrawable和PaintDrawable严重。（特别是在棒棒糖上）似乎对Shaders 进行了调整，因此无法正确处理纯色块。
I am using the following code now:
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;
}
Unlike the others, if you call setBoundson the Drawablebefore asking to turn it into a bitmap, it will draw the bitmap at the correct size!
不像其他人，如果你拨打setBounds的Drawable要求把它变成一个位图前，将以此为位图以正确的尺寸！
回答by Mauro
Maybe this will help someone...
也许这会帮助某人......
From PictureDrawable to Bitmap, use:
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;
}
... implemented as such:
... 实现如下：
Bitmap bmp = pictureDrawableToBitmap((PictureDrawable) drawable);
回答by Dawid Drozd
Here is better resolution
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());
}
Code from How to read drawable bits as InputStream
回答by tasomaniac
Here is the nice Kotlin version of the answer provided by @Chris.Jenkins here: https://stackoverflow.com/a/27543712/1016462
这是@Chris.Jenkins 在这里提供的答案的 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
