前言

UE需要在android的文字上加上阴影效果，之前不知道原来TextView有这样一个属性可以设置文字阴影~记录一下

代码实现

    /**
     * Gives the text a shadow of the specified blur radius and color, the specified
     * distance from its drawn position.
     * <p>
     * The text shadow produced does not interact with the properties on view
     * that are responsible for real time shadows,
     * {@link View#getElevation() elevation} and
     * {@link View#getTranslationZ() translationZ}.
     *
     * @see Paint#setShadowLayer(float, float, float, int)
     *
     * @attr ref android.R.styleable#TextView_shadowColor
     * @attr ref android.R.styleable#TextView_shadowDx
     * @attr ref android.R.styleable#TextView_shadowDy
     * @attr ref android.R.styleable#TextView_shadowRadius
     */
    public void setShadowLayer(float radius, float dx, float dy, int color) {
        mTextPaint.setShadowLayer(radius, dx, dy, color);

        mShadowRadius = radius;
        mShadowDx = dx;
        mShadowDy = dy;
        mShadowColor = color;

        // Will change text clip region
        if (mEditor != null) {
            mEditor.invalidateTextDisplayList();
            mEditor.invalidateHandlesAndActionMode();
        }
        invalidate();
    }

备注： shadowRadius是阴影模糊半径