Android-使用画布在位图外部设置背景颜色的图像覆盖
我正在制作一个相机活动覆盖图,我成功地在矩形外创建了不透明颜色(不透明黑色)。我还成功地在大矩形内创建了一个小矩形。请看下图。如您所见,小矩形上有一个蓝色背景。问题是,我想使蓝色背景在图像(位图)之外,而不是覆盖图像。问题是,如果我用透明填充更改图像,蓝色背景将覆盖所有内容。如何使蓝色背景仅覆盖图像的外部?我已经试着从谷歌上找到所有可能的答案,但我运气不好,也许我开始的方法不对,需要建议 这是我的密码Android-使用画布在位图外部设置背景颜色的图像覆盖,android,image,canvas,bitmap,android-camera,Android,Image,Canvas,Bitmap,Android Camera,我正在制作一个相机活动覆盖图,我成功地在矩形外创建了不透明颜色(不透明黑色)。我还成功地在大矩形内创建了一个小矩形。请看下图。如您所见,小矩形上有一个蓝色背景。问题是,我想使蓝色背景在图像(位图)之外,而不是覆盖图像。问题是,如果我用透明填充更改图像,蓝色背景将覆盖所有内容。如何使蓝色背景仅覆盖图像的外部?我已经试着从谷歌上找到所有可能的答案,但我运气不好,也许我开始的方法不对,需要建议 这是我的密码 bitmap = Bitmap.createBitmap(getWidth(), getHe
bitmap = Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ARGB_8888);
Canvas osCanvas = new Canvas(bitmap);
RectF outerRectangle = new RectF(0, 0, getWidth(), getHeight());
Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
paint.setColor(getResources().getColor(R.color.opaque_black));
paint.setAlpha(99);
osCanvas.drawRect(outerRectangle, paint);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_OUT));
paint.setColor(Color.TRANSPARENT);
paint.setStyle(Paint.Style.FILL);
RectF r1 = new RectF(
(float) (xStartingPoint),
(float) (yStartingPoint),
(float) (parentWidth),
(float) (parentHeight));
osCanvas.drawRoundRect(r1, (float) (cornerRadiusRatio * parentHeight),
(float) (cornerRadiusRatio * parentHeight), paint);
paint.setStrokeWidth(strokeWidth);
paint.setColor(getResources().getColor(R.color.colorDeepSky));
paint.setStyle(Paint.Style.STROKE);
RectF r2 = new RectF(
(float) (xStartingPoint),
(float) (yStartingPoint),
(float) (parentWidth),
(float) (parentHeight));
osCanvas.drawRoundRect(r2, (float) (cornerRadiusRatio * parentHeight),
(float) (cornerRadiusRatio * parentHeight), paint);
if (callbackMsg.equals(AppConstant.KTP_SELF)) {
paint.setColor(getResources().getColor(R.color.colorDeepSky));
drawRect(osCanvas, paint,
(float) (xChildStartingPoint),
(float) (yChildStartingPoint),
(float) (childWidth + xChildStartingPoint + 0.3 * childWidth),
(float) (childHeight + 0.7 * yChildStartingPoint));
}
RectF outerRectangle2 = new RectF(
(float) xChildStartingPoint,
(float) yChildStartingPoint,
(float) (childWidth + xChildStartingPoint + 0.3 * childWidth),
(float) (childHeight + 0.7 * yChildStartingPoint));
Paint paint2 = new Paint(Paint.ANTI_ALIAS_FLAG);
paint2.setColor(getResources().getColor(R.color.blue));
paint2.setAlpha(99);
osCanvas.drawRect(outerRectangle2, paint2);
Rect r3 = new Rect(
(int) (xChildStartingPoint),
(int) (yChildStartingPoint),
(int) (childWidth + xChildStartingPoint + 0.3 * childWidth),
(int) (childHeight + 0.7 * yChildStartingPoint));
paint2 = new Paint(Paint.ANTI_ALIAS_FLAG);
paint2.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_OUT));
paint2.setColor(Color.TRANSPARENT);
paint2.setStyle(Paint.Style.FILL);
Bitmap mbitmap = BitmapFactory.decodeResource(getResources(),R.drawable.icon_profile2);
osCanvas.drawBitmap(mbitmap, null, r3, paint2);
谢谢好的,找到答案了
我使用的是PorterDuff
和DST\u OUT
模式
注:
如果要使图像背景透明且外部区域充满颜色,请使用DST_OUT
如果要使外部区域充满颜色,请使用DST U
这是代码,我在用Kotlin
var paint2 = Paint(Paint.ANTI_ALIAS_FLAG)
paint2.color = resources.getColor(R.color.opaque_black)
osCanvas.drawRect(outerRectangle2, paint2)
paint2 = Paint(Paint.ANTI_ALIAS_FLAG)
val r3 = Rect(
xChildStartingPoint.toInt(),
yChildStartingPoint.toInt(),
(childWidth + xChildStartingPoint + 0.3 * childWidth).toInt(),
(childHeight + 0.7 * yChildStartingPoint).toInt())
paint2.xfermode = PorterDuffXfermode(PorterDuff.Mode.DST_IN)
val mBitmap = BitmapFactory.decodeResource(resources, R.drawable.selfie_outline)
osCanvas.drawBitmap(mBitmap, null, r3, paint2)