android 获取当前屏幕作为毛玻璃模糊背景Acitivity作为弹出框。

使用：

1.在执行弹出界面前，先将其当前屏幕截图。

BlurBuilder.snapShotWithoutStatusBar(getActivity());

2.为了确保界面切入无效果。

startActivity(wechatIntent);
        context.overridePendingTransition(
                android.view.animation.Animation.INFINITE,
                android.view.animation.Animation.INFINITE);

3.在切换的页面中初始化背景ImageView：

private void applyBlur() {
        iv_shared_layout.setImageBitmap(BlurBuilder.blur(iv_shared_layout));
        if (BlurBuilder.isBlurFlag()) {
            iv_shared_layout.setVisibility(View.VISIBLE);
        }
    }

4.在acitivity的super.finish();或者在onDestroy中回收资源：

@Override
    public void finish() {
        defaultFinishNotActivityHelper();
        BlurBuilder.recycle();
        overridePendingTransition(android.view.animation.Animation.INFINITE,
                android.view.animation.Animation.INFINITE);
    }

 

毛玻璃模糊效果使用类：

public class BlurBuilder {

    private static final float BITMAP_SCALE = 0.4f;
    private static final float BLUR_RADIUS = 7.5f;

    private static Bitmap tab_bg = null;
    private static Bitmap overlay = null;
    private static boolean blurFlag = false;

    public static boolean isBlurFlag() {
        return BlurBuilder.blurFlag;
    }

    public static void setBlurFlag(boolean blurFlag) {
        BlurBuilder.blurFlag = blurFlag;
    }

    public static Bitmap blur(View v) {
        if (tab_bg == null) {
            android.util.Log.i("", "tab_bg == null");
            blurFlag = false;
            return null;
        }
        blurFlag = true;
        blur(v.getContext(), tab_bg);
        return overlay;
    }

    public static void blur(Context ctx, Bitmap image) {
        if (overlay != null) {
            recycle();
        }
        try {
            int width = Math.round(image.getWidth() * BITMAP_SCALE);
            int height = Math.round(image.getHeight() * BITMAP_SCALE);

            overlay = Bitmap.createScaledBitmap(image, (int) (width),
                    (int) (height), false);

            overlay = FastBlur.doBlur(overlay, (int) BLUR_RADIUS, true);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void getScreenshot(View v) {
        if (tab_bg != null) {
            recycle();
        }
        try {
            tab_bg = Bitmap.createBitmap(v.getWidth(), v.getHeight(),
                    Bitmap.Config.RGB_565);
            Canvas c = new Canvas(tab_bg);
            v.draw(c);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 获取当前屏幕截图，不包含状态栏
     * 
     * @param activity
     * @return
     */
    public static void snapShotWithoutStatusBar(Activity activity) {
        if (tab_bg != null) {
            recycle();
        }
        View view = activity.getWindow().getDecorView();
        try {
            view.setDrawingCacheEnabled(true);
            view.buildDrawingCache();
            tab_bg = view.getDrawingCache();
            Rect frame = new Rect();
            activity.getWindow().getDecorView()
                    .getWindowVisibleDisplayFrame(frame);
            int statusBarHeight = frame.top;

            int width = ScreenUtils.getScreenWidth(activity);
            int height = ScreenUtils.getScreenHeight(activity);
            tab_bg = Bitmap.createBitmap(tab_bg, 0, statusBarHeight, width,
                    height - statusBarHeight);
            view.destroyDrawingCache();
        } catch (Exception e) {
            e.printStackTrace();
            getScreenshot(view);
        }
    }

    public static void recycle() {

        try {
            if (tab_bg != null) {
                tab_bg.recycle();
                System.gc();
                tab_bg = null;
            }
            if (overlay != null) {
                overlay.recycle();
                System.gc();
                overlay = null;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

毛玻璃模糊效果类：

public class FastBlur {

    public static Bitmap doBlur(Bitmap sentBitmap, int radius,
            boolean canReuseInBitmap) {

        Bitmap bitmap;
        if (canReuseInBitmap) {
            bitmap = sentBitmap;
        } else {
            bitmap = sentBitmap.copy(sentBitmap.getConfig(), true);
        }

        if (radius < 1) {
            return (null);
        }

        int w = bitmap.getWidth();
        int h = bitmap.getHeight();

        int[] pix = new int[w * h];
        bitmap.getPixels(pix, 0, w, 0, 0, w, h);

        int wm = w - 1;
        int hm = h - 1;
        int wh = w * h;
        int div = radius + radius + 1;

        int r[] = new int[wh];
        int g[] = new int[wh];
        int b[] = new int[wh];
        int rsum, gsum, bsum, x, y, i, p, yp, yi, yw;
        int vmin[] = new int[Math.max(w, h)];

        int divsum = (div + 1) >> 1;
        divsum *= divsum;
        int dv[] = new int[256 * divsum];
        for (i = 0; i < 256 * divsum; i++) {
            dv[i] = (i / divsum);
        }

        yw = yi = 0;

        int[][] stack = new int[div][3];
        int stackpointer;
        int stackstart;
        int[] sir;
        int rbs;
        int r1 = radius + 1;
        int routsum, goutsum, boutsum;
        int rinsum, ginsum, binsum;

        for (y = 0; y < h; y++) {
            rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;
            for (i = -radius; i <= radius; i++) {
                p = pix[yi + Math.min(wm, Math.max(i, 0))];
                sir = stack[i + radius];
                sir[0] = (p & 0xff0000) >> 16;
                sir[1] = (p & 0x00ff00) >> 8;
                sir[2] = (p & 0x0000ff);
                rbs = r1 - Math.abs(i);
                rsum += sir[0] * rbs;
                gsum += sir[1] * rbs;
                bsum += sir[2] * rbs;
                if (i > 0) {
                    rinsum += sir[0];
                    ginsum += sir[1];
                    binsum += sir[2];
                } else {
                    routsum += sir[0];
                    goutsum += sir[1];
                    boutsum += sir[2];
                }
            }
            stackpointer = radius;

            for (x = 0; x < w; x++) {

                r[yi] = dv[rsum];
                g[yi] = dv[gsum];
                b[yi] = dv[bsum];

                rsum -= routsum;
                gsum -= goutsum;
                bsum -= boutsum;

                stackstart = stackpointer - radius + div;
                sir = stack[stackstart % div];

                routsum -= sir[0];
                goutsum -= sir[1];
                boutsum -= sir[2];

                if (y == 0) {
                    vmin[x] = Math.min(x + radius + 1, wm);
                }
                p = pix[yw + vmin[x]];

                sir[0] = (p & 0xff0000) >> 16;
                sir[1] = (p & 0x00ff00) >> 8;
                sir[2] = (p & 0x0000ff);

                rinsum += sir[0];
                ginsum += sir[1];
                binsum += sir[2];

                rsum += rinsum;
                gsum += ginsum;
                bsum += binsum;

                stackpointer = (stackpointer + 1) % div;
                sir = stack[(stackpointer) % div];

                routsum += sir[0];
                goutsum += sir[1];
                boutsum += sir[2];

                rinsum -= sir[0];
                ginsum -= sir[1];
                binsum -= sir[2];

                yi++;
            }
            yw += w;
        }
        for (x = 0; x < w; x++) {
            rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;
            yp = -radius * w;
            for (i = -radius; i <= radius; i++) {
                yi = Math.max(0, yp) + x;

                sir = stack[i + radius];

                sir[0] = r[yi];
                sir[1] = g[yi];
                sir[2] = b[yi];

                rbs = r1 - Math.abs(i);

                rsum += r[yi] * rbs;
                gsum += g[yi] * rbs;
                bsum += b[yi] * rbs;

                if (i > 0) {
                    rinsum += sir[0];
                    ginsum += sir[1];
                    binsum += sir[2];
                } else {
                    routsum += sir[0];
                    goutsum += sir[1];
                    boutsum += sir[2];
                }

                if (i < hm) {
                    yp += w;
                }
            }
            yi = x;
            stackpointer = radius;
            for (y = 0; y < h; y++) {
                // Preserve alpha channel: ( 0xff000000 & pix[yi] )
                pix[yi] = (0xff000000 & pix[yi]) | (dv[rsum] << 16)
                        | (dv[gsum] << 8) | dv[bsum];

                rsum -= routsum;
                gsum -= goutsum;
                bsum -= boutsum;

                stackstart = stackpointer - radius + div;
                sir = stack[stackstart % div];

                routsum -= sir[0];
                goutsum -= sir[1];
                boutsum -= sir[2];

                if (x == 0) {
                    vmin[y] = Math.min(y + r1, hm) * w;
                }
                p = x + vmin[y];

                sir[0] = r[p];
                sir[1] = g[p];
                sir[2] = b[p];

                rinsum += sir[0];
                ginsum += sir[1];
                binsum += sir[2];

                rsum += rinsum;
                gsum += ginsum;
                bsum += binsum;

                stackpointer = (stackpointer + 1) % div;
                sir = stack[stackpointer];

                routsum += sir[0];
                goutsum += sir[1];
                boutsum += sir[2];

                rinsum -= sir[0];
                ginsum -= sir[1];
                binsum -= sir[2];

                yi += w;
            }
        }

        bitmap.setPixels(pix, 0, w, 0, 0, w, h);

        return (bitmap);
    }
}