在我的应用程序中,我必须为通知设置一个大图标。 LargeIcon 必须是位图,而我的可绘制对象是矢量图像(Android 中的新功能,请参阅 this link) 问题是当我尝试解码矢量图像资源时,返回 null。
这是代码示例:
if (BitmapFactory.decodeResource(arg0.getResources(), R.drawable.vector_menu_objectifs) == null)
Log.d("ISNULL", "NULL");
else
Log.d("ISNULL", "NOT NULL");
在此示例中,当我将 R.drawable.vector_menu_objectifs 替换为“正常”图像(例如 png)时,结果不为空(我得到正确的位图)我缺少什么吗?
检查 API:17、21、23
public static Bitmap getBitmapFromVectorDrawable(Context context, int drawableId) {
Drawable drawable = ContextCompat.getDrawable(context, drawableId);
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
drawable = (DrawableCompat.wrap(drawable)).mutate();
}
Bitmap 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;
}
更新:
项目等级:
dependencies {
classpath 'com.android.tools.build:gradle:2.2.0-alpha5'
}
模块分级:
android {
compileSdkVersion 23
buildToolsVersion '23.0.3'
defaultConfig {
minSdkVersion 16
targetSdkVersion 23
vectorDrawables.useSupportLibrary = true
}
...
}
...
如果您愿意将 Android KTX 用于 Kotlin,您可以使用扩展方法 Drawable#toBitmap()
来达到与其他答案相同的效果:
val bitmap = AppCompatResources.getDrawable(requireContext(), drawableId).toBitmap()
或者
val bitmap = AppCompatResources.getDrawable(context, drawableId).toBitmap()
要添加此方法和其他有用的扩展方法,您需要将以下内容添加到您的模块级 build.gradle
repositories {
google()
}
dependencies {
implementation "androidx.core:core-ktx:1.2.0"
}
有关将依赖项添加到项目的最新说明,请参阅 here。
请注意,这适用于 Drawable
的 any 子类,如果 Drawable
是 BitmapDrawable
,它将使用基础 Bitmap
的快捷方式。
VectorDrawable
配合得很好。
您可以使用以下方法:
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
private static Bitmap getBitmap(VectorDrawable vectorDrawable) {
Bitmap bitmap = Bitmap.createBitmap(vectorDrawable.getIntrinsicWidth(),
vectorDrawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
vectorDrawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
vectorDrawable.draw(canvas);
return bitmap;
}
我有时会结合:
private static Bitmap getBitmap(Context context, int drawableId) {
Drawable drawable = ContextCompat.getDrawable(context, drawableId);
if (drawable instanceof BitmapDrawable) {
return ((BitmapDrawable) drawable).getBitmap();
} else if (drawable instanceof VectorDrawable) {
return getBitmap((VectorDrawable) drawable);
} else {
throw new IllegalArgumentException("unsupported drawable type");
}
}
Bitmap bitmap = Bitmap.createBitmap(vectorDrawable.getIntrinsicWidth(), vectorDrawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
上不起作用 Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.graphics.Bitmap.setHasAlpha(boolean)' on a null object reference
根据前面的答案,可以像这样简化它以匹配 VectorDrawable 和 BitmapDrawable 并至少与 API 15 兼容。
public static Bitmap getBitmapFromDrawable(Context context, @DrawableRes int drawableId) {
Drawable drawable = AppCompatResources.getDrawable(context, drawableId);
if (drawable instanceof BitmapDrawable) {
return ((BitmapDrawable) drawable).getBitmap();
} else if (drawable instanceof VectorDrawableCompat || drawable instanceof VectorDrawable) {
Bitmap 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;
} else {
throw new IllegalArgumentException("unsupported drawable type");
}
}
然后你必须在你的 gradle 文件中添加:
android {
defaultConfig {
vectorDrawables.useSupportLibrary = true
}
}
在 pre-Lollipop 上它将使用 VectorDrawableCompat,在 Lollipop 上它将使用 VectorDrawable。
编辑
我根据@user3109468 的评论编辑了条件
编辑 2 (10/2020)
至少从 API 21 开始,您现在可以使用它而不是上面的代码(我没有尝试过以前的 API 版本):
AppCompatResources.getDrawable(context, R.drawable.your_drawable)
(Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP && drawable instanceof VectorDrawable)
感谢@Alexey
这是使用 Context
扩展的 Kotlin
版本
fun Context.getBitmapFromVectorDrawable(drawableId: Int): Bitmap? {
var drawable = ContextCompat.getDrawable(this, drawableId) ?: return null
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
drawable = DrawableCompat.wrap(drawable).mutate()
}
val bitmap = Bitmap.createBitmap(
drawable.intrinsicWidth,
drawable.intrinsicHeight,
Bitmap.Config.ARGB_8888) ?: return null
val canvas = Canvas(bitmap)
drawable.setBounds(0, 0, canvas.width, canvas.height)
drawable.draw(canvas)
return bitmap
}
Activity
中的示例用法:
val bitmap = this.getBitmapFromVectorDrawable(R.drawable.ic_done_white_24dp)
在 API 16 上测试 - 带有 Vector Drawable 的 JellyBean
public static Bitmap getBitmapFromVectorDrawable(Context context, int drawableId) {
Drawable drawable = AppCompatResources.getDrawable(context, drawableId);
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
drawable = (DrawableCompat.wrap(drawable)).mutate();
}
Bitmap 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;
}
对于矢量drawable,这里给出了cup代码帮助我们,但请记住,如果drawable未找到NULL,它可能为null
@Nullable
public static Bitmap drawableToBitmap(Context context, int drawableId) {
Drawable drawable = ContextCompat.getDrawable(context, drawableId);
if (drawable != null) {
int width = drawable.getIntrinsicWidth();
int height = drawable.getIntrinsicHeight();
Bitmap bmp = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bmp);
drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
drawable.draw(canvas);
return bmp;
}
return null;
}
使用以下代码转换具有正确纵横比的图像(例如,用于通知图标):
public static Bitmap getBitmapFromVector(Context context, int drawableId) {
Drawable drawable = ContextCompat.getDrawable(context, drawableId);
int width = drawable.getIntrinsicWidth();
int height = drawable.getIntrinsicHeight();
Bitmap bitmap;
if (width < height) { //make a square
bitmap = Bitmap.createBitmap(height, height, Bitmap.Config.ARGB_8888);
} else {
bitmap = Bitmap.createBitmap(width, width, Bitmap.Config.ARGB_8888);
}
Canvas canvas = new Canvas(bitmap);
drawable.setBounds(0, 0,
drawable.getIntrinsicWidth(), //use dimensions of Drawable
drawable.getIntrinsicHeight()
);
drawable.draw(canvas);
return bitmap;
}
如果您的 vector
图像 intrinsicWidth
和 intrinsicHeight
很小,并且您尝试将位图显示为大视图,那么您将看到结果是模糊的。
在这种情况下,您可以为位图提供新的宽度/高度以获得更好的图像(或者您可以增加 xml 中的矢量大小,但提供 desireWidth
和 desireHeight
可能更灵活)。
private fun getBitmap(drawableId: Int, desireWidth: Int? = null, desireHeight: Int? = null): Bitmap? {
val drawable = AppCompatResources.getDrawable(context, drawableId) ?: return null
val bitmap = Bitmap.createBitmap(
desireWidth ?: drawable.intrinsicWidth,
desireHeight ?: drawable.intrinsicHeight,
Bitmap.Config.ARGB_8888
)
val canvas = Canvas(bitmap)
drawable.setBounds(0, 0, canvas.width, canvas.height)
drawable.draw(canvas)
return bitmap
}
希望有帮助
Drawable layerDrawable = (Drawable) imageBase.getDrawable();
Bitmap bitmap = Bitmap.createBitmap(layerDrawable.getIntrinsicWidth(),
layerDrawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
layerDrawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
layerDrawable.draw(canvas);
imageTeste.setImageBitmap(addGradient(bitmap));
如果您希望能够将输出缩放到所需的输出大小,请尝试以下代码段:
fun getBitmapFromVectorDrawable(context: Context, drawableId: Int, outputSize: OutputSize? = null): Bitmap? {
var drawable = ContextCompat.getDrawable(context, drawableId) ?: return null
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
drawable = DrawableCompat.wrap(drawable).mutate()
}
var targetBitmap: Bitmap
if (outputSize != null) {
targetBitmap = Bitmap.createBitmap(outputSize.width,
outputSize.height, Bitmap.Config.ARGB_8888)
} else {
targetBitmap = Bitmap.createBitmap(drawable.intrinsicWidth,
drawable.intrinsicHeight, Bitmap.Config.ARGB_8888)
}
val canvas = Canvas(targetBitmap)
val scaleX = targetBitmap.width.toFloat()/drawable.intrinsicWidth.toFloat()
val scaleY = targetBitmap.height.toFloat()/drawable.intrinsicHeight.toFloat()
canvas.scale(scaleX, scaleY)
drawable.draw(canvas)
return targetBitmap
}
class OutputSize(val width: Int, val height: Int)
这将为您提供所需大小的位图。此外,它允许您根据每个图像保持或不保持透明度,以便在不需要它的图像中获得更好的性能。
public static Bitmap drawableToBitmap(Resources res, int drawableId,
int width, int height, boolean keepAlpha) {
Drawable drawable = res.getDrawable(drawableId);
Bitmap bmp = createBitmap(width, height, keepAlpha ?
Bitmap.Config.ARGB_8888 : Bitmap.Config.RGB_565);
Canvas cvs = new Canvas(bmp);
drawable.setBounds(0, 0, width, height);
drawable.draw(cvs);
return bmp;
}
创造Vector to Bitmap的独立乐趣
//vectorToBitmapMarker
private fun fromVectorToBitmap(id: Int, color: Int): BitmapDescriptor
{
val vectorDrawable: Drawable? = ResourcesCompat.getDrawable(resources, id, null)
if (vectorDrawable == null)
{
d("VTOB","Resource not found!")
return BitmapDescriptorFactory.defaultMarker()
}
val bitmap = Bitmap.createBitmap(
vectorDrawable.intrinsicWidth,
vectorDrawable.intrinsicHeight,
Bitmap.Config.ARGB_8888)
val canvas = Canvas(bitmap)
vectorDrawable.setBounds(0,0,canvas.width, canvas.height)
DrawableCompat.setTint(vectorDrawable, color)
vectorDrawable.draw(canvas)
return BitmapDescriptorFactory.fromBitmap(bitmap)
}
现在在 onMapReady() -> .icon() 中进行更改
mMap.addMarker(
MarkerOptions().position(goa)
.title("Marker in Goa")
.draggable(true)
.icon(fromVectorToBitmap(R.drawable.location, Color.parseColor("#FF0560"))))
不定期副业成功案例分享
AppCompatDrawableManager
被标记为@RestrictTo(LIBRARY_GROUP)
,因此它是内部的,您不应使用它(它的 API 可能会更改,恕不另行通知)。请改用ContextCompat
。Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
上不起作用Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.graphics.Bitmap.setHasAlpha(boolean)' on a null object reference