Android 绘制发光效果

之前在看别人写自定义view作绘制的时候，看到别人家的view自带发光效果，看起来也是蛮炫酷的，于是自己也抽出时间来试用一下，这里做了一个模仿太阳的各种状态样式。

先上效果先上效果：

实现方式：

public BlurMaskFilter(float radius, Blur style) {

实现是使用的Paint类的setMaskFilter()方法，传入BlurMaskFilter对象实现高斯模糊发光。

• float radius 设置模糊半径
• Blur style 设置发光样式，包括
  Blur.INNER(内发光)，Blur.NORMAL(内外发光)
  Blur.SOLID(外发光)，Blur.OUTER(仅外发光可见)

贴上代码

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);
    }
}