很久以前就想自己实现一下仿微信图片加载的那种策略了，先加载一张模糊的图片，然后再加载清晰大图，今天研究了一下，不过要是Glide支持进度条显示就好了，不得不说Glide很强大，
不啰嗦了，直接上代码了。
首先看看高斯模糊到底怎么实现，你问我我也不会(^__^) 嘻嘻……，直接附上网上的算法：
package com.cisetech.dialogdemo;import android.graphics.Bitmap;/*** Author:Yqy* Date:-09-29* Desc:* Company:cisetech*/public class FastBlur {public static Bitmap doBlur(Bitmap sentBitmap, int radius, boolean canReuseInBitmap) {// Stack Blur v1.0 from// /StackBlurForCanvas/StackBlurDemo.html//// Java Author: Mario Klingemann <mario at >// // created Feburary 29, // Android port : Yahel Bouaziz <yahel at >// // ported april 5th, // This is a compromise between Gaussian Blur and Box blur// It creates much better looking blurs than Box Blur, but is// 7x faster than my Gaussian Blur implementation.//// I called it Stack Blur because this describes best how this// filter works internally: it creates a kind of moving stack// of colors whilst scanning through the image. Thereby it// just has to add one new block of color to the right side// of the stack and remove the leftmost color. The remaining// colors on the topmost layer of the stack are either added on// or reduced by one, depending on if they are on the right or// on the left side of the stack.//// If you are using this algorithm in your code please add// the following line://// Stack Blur Algorithm by Mario Klingemann <mario@>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);}}
由于代码比较少，我就直接全部粘贴了，可以直接拿去研究额。
package com.cisetech.dialogdemo;import android.app.Dialog;import android.content.Context;import android.graphics.Bitmap;import android.graphics.Color;import android.graphics.drawable.ColorDrawable;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.util.DisplayMetrics;import android.util.Log;import android.view.LayoutInflater;import android.view.View;import android.view.WindowManager;import android.widget.ImageView;import android.widget.ProgressBar;import com.bumptech.glide.Glide;import com.bumptech.glide.load.engine.DiskCacheStrategy;import com.bumptech.glide.load.engine.bitmap_recycle.BitmapPool;import com.bumptech.glide.load.resource.bitmap.BitmapTransformation;import com.bumptech.glide.load.resource.drawable.GlideDrawable;import com.bumptech.glide.request.RequestListener;import com.bumptech.glide.request.target.Target;public class MainActivity extends AppCompatActivity {private int screenWidth;private ImageView id_iv;private ProgressBar pb;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);WindowManager wm=getWindowManager();DisplayMetrics outMetrics=new DisplayMetrics();wm.getDefaultDisplay().getMetrics(outMetrics);screenWidth=outMetrics.widthPixels;id_iv= (ImageView) findViewById(R.id.id_iv);pb= (ProgressBar) findViewById(R.id.pb);Glide.with(this).load("/img/image/shouye/xinshouye/dongman928.jpg").centerCrop().listener(new RequestListener<String, GlideDrawable>() {@Overridepublic boolean onException(Exception e, String s, Target<GlideDrawable> target, boolean b) {return false;}@Overridepublic boolean onResourceReady(final GlideDrawable glideDrawable, String s, Target<GlideDrawable> target, boolean b, boolean b1) {Log.e("TAG", "onResourceReady: target-------->"+target );Log.e("TAG", "onResourceReady: glideDrawable-------->"+glideDrawable );Glide.with(MainActivity.this).load("/img/image/shouye/xinshouye/dongman928.jpg").centerCrop().placeholder(glideDrawable).diskCacheStrategy(DiskCacheStrategy.NONE).skipMemoryCache(true).dontAnimate().crossFade(1000).listener(new RequestListener<String, GlideDrawable>() {@Overridepublic boolean onException(Exception e, String s, Target<GlideDrawable> target, boolean b) {return false;}@Overridepublic boolean onResourceReady(GlideDrawable glideDrawable, String s, Target<GlideDrawable> target, boolean b, boolean b1) {pb.setVisibility(View.GONE);return false;}}).into(id_iv);return false;}}).transform(new MyTransformtion(this)).diskCacheStrategy(DiskCacheStrategy.ALL).placeholder(new ColorDrawable(Color.BLACK)).dontAnimate().into(id_iv);//createLoadingDialog(this).show();}public Dialog createLoadingDialog(Context context) {LayoutInflater inflater = LayoutInflater.from(context);View v = inflater.inflate(R.layout.wechat_dialog, null);// 得到加载viewDialog loadingDialog = new Dialog(context, R.style.loading_dialog);// 创建自定义样式dialogloadingDialog.setCancelable(false);// 不可以用“返回键”取消loadingDialog.setContentView(v);// 设置布局/*** 设置Dialog的宽度为屏幕宽度的61.8%，高度为自适应*/WindowManager.LayoutParams lp = loadingDialog.getWindow().getAttributes();lp.width= (int) (screenWidth*0.618f);lp.height=lp.WRAP_CONTENT;loadingDialog.getWindow().setAttributes(lp);return loadingDialog;}public class MyTransformtion extends BitmapTransformation{public MyTransformtion(Context context) {super(context);}@Overrideprotected Bitmap transform(BitmapPool bitmapPool, Bitmap bitmap, int i, int i1) {Log.e("TAG", "transform: bitmap-------->"+bitmap );return FastBlur.doBlur(bitmap,10,true);}@Overridepublic String getId() {return "com.cisetech.dialogdemo.MyTransformtion";}}}
仿微信进度条可以看我另外一篇博客Android进阶之（Dailog详解），这里写在一个工程里面了，我就直接贴代码了。
源码链接：/s/1gflwaFx
