setShadowLayour的属性介绍

setShadowLayer(float radius, float dx, float dy, int shadowColor)

radius表示阴影的扩散半径；dx和dy表示阴影平面上的偏移值；shadowColor就不说了阴影颜色。

注意： 这个方法不支持硬件加速，所以我们要测试时必须先关闭硬件加速。

加上这一句 setLayerType(LAYER_TYPE_SOFTWARE, null); 还要注释@SuppressLint(“NewApi”）

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创建阴影的方法:

//创建shadow private void createShadow() { if (shadowEffect) { Bitmap shadowBitmap = createShadowBitmap(); BitmapDrawable shadowDrawable = new BitmapDrawable(getResources(), shadowBitmap); if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.JELLY_BEAN) { //noinspection deprecation setBackgroundDrawable(shadowDrawable); } else { setBackground(shadowDrawable); } } else { clearShadow(); } } private Bitmap createShadowBitmap() { Bitmap shadowBitmap = Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ALPHA_8); Canvas canvas = new Canvas(shadowBitmap); RectF shadowRect = new RectF( shadowRadius + Math.abs(shadowOffsetX), shadowRadius + Math.abs(shadowOffsetY), getWidth() - shadowRadius - Math.abs(shadowOffsetX), getHeight() - shadowRadius - Math.abs(shadowOffsetY)); Paint shadowPaint = new Paint(); shadowPaint.setAntiAlias(true); shadowPaint.setColor(Color.TRANSPARENT); shadowPaint.setStyle(Paint.Style.FILL); if (!isInEditMode()) { //设置Shadow的层级 radius表示阴影的扩散半径；dx和dy表示阴影平面上的偏移值；shadowColor就不说了阴影颜色。 shadowPaint.setShadowLayer(shadowRadius, shadowOffsetX, shadowOffsetY, shadowColor); } canvas.drawRoundRect(shadowRect, shadowCornerRadius, shadowCornerRadius, shadowPaint); return shadowBitmap; }