尝试使用遮罩裁剪位图会抛出 IllegalArgumentException:

trying to crop bitmap using mask throws IllegalArgumentException:

我正在使用以下代码

public void cropSelection(){
    Bitmap bitmap = annotationBitmap.copy(annotationBitmap.getConfig(), true);
    Canvas canvas = new Canvas(bitmap);
    Paint p = new Paint();
    // p.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.XOR));
    canvas.drawBitmap(imageBitmap, 0, 0, p); // this line throws error
    imageBitmap = bitmap;
}

更令人惊讶的是,当我在 onDraw() 中使用同一行 canvas.drawBitmap(imageBitmap, 0, 0, p) 时,它不会抛出任何错误。效果很好。

堆栈跟踪

2020-01-17 11:20:07.815 21388-21388/com.mayank.picturemagic E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.mayank.picturemagic, PID: 21388
java.lang.IllegalArgumentException: Software rendering doesn't support hardware bitmaps
    at android.graphics.BaseCanvas.onHwBitmapInSwMode(BaseCanvas.java:550)
    at android.graphics.BaseCanvas.throwIfHwBitmapInSwMode(BaseCanvas.java:557)
    at android.graphics.BaseCanvas.throwIfCannotDraw(BaseCanvas.java:69)
    at android.graphics.BaseCanvas.drawBitmap(BaseCanvas.java:109)
    at android.graphics.Canvas.drawBitmap(Canvas.java:1456)
    at com.mayank.picturemagic.MainView.cropSelection(MainView.java:434)
    at com.mayank.picturemagic.k.onClick(k.java:330)
    at android.view.View.performClick(View.java:6608)
    at android.view.View.performClickInternal(View.java:6585)
    at android.view.View.access00(View.java:785)
    at android.view.View$PerformClick.run(View.java:25921)
    at android.os.Handler.handleCallback(Handler.java:873)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:201)
    at android.app.ActivityThread.main(ActivityThread.java:6810)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:873)

终于有了一个漂亮的解决方案

imageBitmap = imageBitmap.copy(Bitmap.Config.ARGB_8888, true);

基本上从位图中删除硬件配置。

为了解决这个问题,早些时候我尝试 imageBitmap = imageBitmap.copy(imageBitmap.getConfig(), true); 在这种情况下,配置是硬件,它会抛出错误硬件位图总是不可变的。

但是应该有更有效的解决方案以及问题的一部分 - why this works inside onDraw() but not outside remains