ChatGPT解决这个技术问题 Extra ChatGPT

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?

有类似的问题,不是解决方案,而是一种解决方法:stackoverflow.com/questions/33548447/…

H
Hugo Gresse

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
    }
    ...
}
...

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
在此行 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
@mradzinski 很好,它正在工作。我已经编辑了答案以更好地反映最佳解决方案。
我对此解决方案有疑问。对于我使用: AppCompatResources 而不是 ContextCompat 修复它: Drawable drawable = AppCompatResources.getDrawable(context, drawableId);
这对我很有用。在 API 28 上运行没有问题
D
David Rawson

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 Drawableany 子类,如果 DrawableBitmapDrawable,它将使用基础 Bitmap 的快捷方式。


这是 Kotlin 最简单的解决方案。
对我来说,它与 VectorDrawable 配合得很好。
这是最好的选择.. 默认 androidx 提供功能
s
snodnipper

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");
    }
}

希望@liltof 回来并将其标记为答案。需要注意的一件事是,这两种方法都需要 targetAPi 包装器——但 android studio 会告诉你这一点。
我花了大约两天时间尝试这样做,现在考虑它的 svg 文件问题。谢谢!
在此行 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
E
Eselfar

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)

VectorDrawable 的可绘制实例 || drawable instanceof VectorDrawableCompat 应该交换边。当 VectorDrawable 不存在时会导致 Class Not Found,此时应首先检查 VectorDrawableCompat,因为它确实存在。
VertorDrawable 的类型检查可以描述为 (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP && drawable instanceof VectorDrawable)
G
Gunhan

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)

J
James Douglas

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;
}   

K
Kishan Donga

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;
}

a
antaki93

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;
}

L
Linh

如果您的 vector 图像 intrinsicWidthintrinsicHeight 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 desireWidthdesireHeight 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


I
Ivan
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));

H
Hans

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)

E
Estid Felipe Lozano Reyes

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;
}

K
Kuldeep Rathod

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"))))