Android如何绘制发光效果详解

public BlurMaskFilter(float radius, Blur style) {

public class MaskFilterView extends View {
 private Paint lightPaint;
 private int centerX, centerY;
 /** 发光范围 */
 private int radioRadius = 70;

 public MaskFilterView(Context context) {
 super(context);
 init();
 }

 public MaskFilterView(Context context, @Nullable AttributeSet attrs) {
 super(context, attrs);
 init();
 }

 private void init() {
 lightPaint = new Paint();
 setLayerType(LAYER_TYPE_SOFTWARE, null);
 lightPaint.setColor(Color.parseColor("#EC3E3E"));
 lightPaint.setMaskFilter(new BlurMaskFilter(radioRadius, BlurMaskFilter.Blur.INNER));
 }

 @Override
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
 centerX = getLeft() + getMeasuredWidth()/2;
 centerY = getTop() + getMeasuredHeight()/2;
 super.onMeasure(widthMeasureSpec, widthMeasureSpec);
 }

 public void setBlurType(int blurType) {
 switch (blurType) {
  case 0:
  lightPaint.setMaskFilter(new BlurMaskFilter(radioRadius, BlurMaskFilter.Blur.INNER));
  break;
  case 1:
  lightPaint.setMaskFilter(new BlurMaskFilter(radioRadius, BlurMaskFilter.Blur.NORMAL));
  break;
  case 2:
  lightPaint.setMaskFilter(new BlurMaskFilter(radioRadius, BlurMaskFilter.Blur.SOLID));
  break;
  case 3:
  lightPaint.setMaskFilter(new BlurMaskFilter(radioRadius, BlurMaskFilter.Blur.OUTER));
  break;
 }

 invalidate();
 }

 @Override
 protected void onDraw(Canvas canvas) {
 super.onDraw(canvas);

 canvas.drawCircle(centerX, centerY, 150, lightPaint);
 }
}