Android的油漆PorterDuff.Mode.CLEAR对我的看法绘制黑色 [英] Android Paint PorterDuff.Mode.CLEAR drawing black color on my view
问题描述
我要实现橡皮擦为我的绘画应用程序。我可以用下面的code删除
I want to implement eraser for my painting app . I am able to erase with the following code
paint.setColor(0x00000000);
paint.setAlpha(0x00);
但是,当你开始绘制擦除后再次不正确绘制,所以任何想法抹去油漆请建议。
But after erasing when you start painting again it does not paint properly so any idea to erase paint please suggest.
推荐答案
试试下面的code。
paint.setAlpha(0xFF);//transperent color
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));//clear the draw
也看看下的文件夹中的图形API演示样品FingerPaint.java。
Also have a look at the sample FingerPaint.java in the api demos under the folder graphics.
setAlpha(int a)
助手来的setColor(),只有指定颜色的alpha值,其留下的R,G,B值不变。
Helper to setColor(), that only assigns the color's alpha value, leaving its r,g,b values unchanged.
http://developer.android.com/reference/android/graphics/ Paint.html 。看看一对
文档。
http://developer.android.com/reference/android/graphics/Paint.html. Have a look a the documentation.
编辑:
另外,请查阅本
https://开头code。 google.com/p/android/issues/detail?id=54105#c1
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