android - view.getDrawingCache() 在 Android API 28 中被弃用

Question

在 android API 28 中，view.getDrawingCache() 已被弃用。是否有更新的解决方案来生成 android 中特定 View 的位图。

Answer 1

获取view位图的两种方式

1. 使用 Canvas
2. 使用像素 API

---

Canvas Java

Bitmap getBitmapFromView(View view) {
    Bitmap bitmap = Bitmap.createBitmap(
        view.getWidth(), view.getHeight(), Bitmap.Config.ARGB_8888
    );
    Canvas canvas = new Canvas(bitmap);
    view.draw(canvas);
    return bitmap;
}

Bitmap getBitmapFromView(View view,int defaultColor) {
    Bitmap bitmap = Bitmap.createBitmap(
        view.getWidth(), view.getHeight(), Bitmap.Config.ARGB_8888
    );
    Canvas canvas = new Canvas(bitmap);
    canvas.drawColor(defaultColor);
    view.draw(canvas);
    return bitmap;
}

Canvas Kotlin

fun getBitmapFromView(view: View): Bitmap {
    val bitmap = Bitmap.createBitmap(
        view.width, view.height, Bitmap.Config.ARGB_8888
    )
    val canvas = Canvas(bitmap)
    view.draw(canvas)
    return bitmap
}

fun getBitmapFromView(view: View, defaultColor: Int): Bitmap {
    val bitmap = Bitmap.createBitmap(
        view.width, view.height, Bitmap.Config.ARGB_8888
    )
    val canvas = Canvas(bitmap)
    canvas.drawColor(defaultColor)
    view.draw(canvas)
    return bitmap
}

例子

//@param rootView is View object which you want to get bitmap
Bitmap bitmap = getBitmapFromView(rootView);
Bitmap bitmapColored = getBitmapFromView(rootView,Color.WHITE);

像素复制 API

https://stackoverflow.com/a/52985554/9909365

fun getBitmapFromView(view: View, activity: Activity, callback: (Bitmap) -> Unit) {
    activity.window?.let { window ->
        val bitmap = Bitmap.createBitmap(view.width, view.height, Bitmap.Config.ARGB_8888)
        val locationOfViewInWindow = IntArray(2)
        view.getLocationInWindow(locationOfViewInWindow)
        try {
            PixelCopy.request(window, Rect(locationOfViewInWindow[0], locationOfViewInWindow[1], locationOfViewInWindow[0] + view.width, locationOfViewInWindow[1] + view.height), bitmap, { copyResult ->
                if (copyResult == PixelCopy.SUCCESS) {
                    callback(bitmap)
                }
                // possible to handle other result codes ...
            }, Handler())
        } catch (e: IllegalArgumentException) {
            // PixelCopy may throw IllegalArgumentException, make sure to handle it
            e.printStackTrace()
        }
    }
}

有关更多信息，请参阅

Bitmaps

Canvas