在正常的开发中，经常会遇到打开一个界面，只打开的一半，这种情况，背景怎么去处理？

其实使用毛玻璃虚化是最方便的处理方法。

这个首先就需要获取到，这个时候背景图片的截图。可以通过DrawCache来获取。

view.setDrawingCacheEnabled(true);//设置能否缓存图片信息（drawing cache）

view.buildDrawingCache();//如果能够缓存图片，则创建图片缓存 Bitmap bitmap = view.getDrawingCache();//如果图片已经缓存，返回一个bitmap

Bitmap bitmap1 = FastBlurUtils.toBlur(bitmap, 5);　　　　//这个方法就是把得到的bitmap缓存，转换为毛玻璃的效果，具体方法直接上代码，拿去就可以使用。  参数 5 增大，可以得到更高程度的虚化，不过会导致CPU更加intensive iv.setImageBitmap(bitmap1)；

mChatListView.destroyDrawingCache();//使用完之后，释放缓存占用的资源 Glide通过transform也可以转化为毛玻璃效果，但是试了几次都没有成功。

.bitmapTransform(new CropCircleTransformation(this))　　　　//这个是转换为圆形。   添加下面这个依赖库，  可以进行很多的图片转换

.bitmapTransform(new BlurTransformation(context, 25), new CropCircleTransformation(context))　　　　//对图片进行虚化和圆形裁剪，两个效果一起加上，就这样使用，用“，”隔开就可以了

compile 'jp.wasabeef:glide-transformations:2.0.2'

这个类可以直接拿去使用

public class FastBlurUtils {
   /**      * 根据imagepath获取bitmap */ /** * 得到本地或者网络上的bitmap url - 网络或者本地图片的绝对路径,比如: * 
 * A.网络路径: url="http://blog.foreverlove.us/girl2.png" ; * 
 * B.本地路径:url="file://mnt/sdcard/photo/image.png"; * 
 * C.支持的图片格式 ,png, jpg,bmp,gif等等 * * @param url * @return */ public static int IO_BUFFER_SIZE = 2 * 1024; public static Bitmap GetUrlBitmap(String url, int scaleRatio) { int blurRadius = 8;//通常设置为8就行。 if (scaleRatio <= 0) { scaleRatio = 10; } Bitmap originBitmap = null; InputStream in = null; BufferedOutputStream out = null; try { in = new BufferedInputStream(new URL(url).openStream(), IO_BUFFER_SIZE); final ByteArrayOutputStream dataStream = new ByteArrayOutputStream(); out = new BufferedOutputStream(dataStream, IO_BUFFER_SIZE); copy(in, out); out.flush(); byte[] data = dataStream.toByteArray(); originBitmap = BitmapFactory.decodeByteArray(data, 0, data.length); Bitmap scaledBitmap = Bitmap.createScaledBitmap(originBitmap, originBitmap.getWidth() / scaleRatio, originBitmap.getHeight() / scaleRatio, false); Bitmap blurBitmap = doBlur(scaledBitmap, blurRadius, true); return blurBitmap; } catch (IOException e) { e.printStackTrace(); return null; } } private static void copy(InputStream in, OutputStream out) throws IOException { byte[] b = new byte[IO_BUFFER_SIZE]; int read; while ((read = in.read(b)) != -1) { out.write(b, 0, read); } } // 把本地图片毛玻璃化 public static Bitmap toBlur(Bitmap originBitmap, int scaleRatio) { // int scaleRatio = 10; // 增大scaleRatio缩放比，使用一样更小的bitmap去虚化可以到更好的得模糊效果，而且有利于占用内存的减小； int blurRadius = 5;//通常设置为8就行。 //增大blurRadius，可以得到更高程度的虚化，不过会导致CPU更加intensive /* 其中前三个参数很明显，其中宽高我们可以选择为原图尺寸的1/10； 第四个filter是指缩放的效果，filter为true则会得到一个边缘平滑的bitmap， 反之，则会得到边缘锯齿、pixelrelated的bitmap。 这里我们要对缩放的图片进行虚化，所以无所谓边缘效果，filter=false。*/ if (scaleRatio <= 0) { scaleRatio = 10; } Bitmap scaledBitmap = Bitmap.createScaledBitmap(originBitmap, originBitmap.getWidth() / scaleRatio, originBitmap.getHeight() / scaleRatio, false); Bitmap blurBitmap = doBlur(scaledBitmap, blurRadius, true); return blurBitmap; } 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); } }