1，在项目中我们常有这样的需求，就是在个人中心的时候，当用户登录后，要显示用户登陆后的头像，然后背景是用户头像的虚化 ，接下来就来实现一下这个功能，先看一下效果
2，实现起来也挺简单的，没什么难度 ，不多说，直接上代码
contain_main.xml
<?xml version="1.0" encoding="utf-8"?><RelativeLayoutxmlns:android="/apk/res/android"xmlns:app="/apk/res-auto"xmlns:tools="/tools"android:id="@+id/rl_content"android:layout_width="match_parent"android:layout_height="wrap_content"app:layout_behavior="@string/appbar_scrolling_view_behavior"tools:context="com.wangjitao.bluedemotest.MainActivity"tools:showIn="@layout/activity_main"><ImageViewandroid:id="@+id/imageview_ll"android:layout_width="match_parent"android:layout_height="300dp"android:scaleType="fitXY"/><ImageViewandroid:id="@+id/imageview"android:layout_width="64dp"android:layout_height="64dp"android:layout_centerInParent="true"/></RelativeLayout>
MainActivity.java
package com.wangjitao.bluedemotest;import android.content.Context;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Canvas;import android.graphics.drawable.BitmapDrawable;import android.os.Bundle;import android.renderscript.Allocation;import android.renderscript.RenderScript;import android.renderscript.ScriptIntrinsicBlur;import android.support.design.widget.FloatingActionButton;import android.support.design.widget.Snackbar;import android.support.v7.app.AppCompatActivity;import android.support.v7.widget.Toolbar;import android.view.View;import android.view.Menu;import android.view.MenuItem;import android.widget.ImageView;import android.widget.RelativeLayout;import com.squareup.picasso.Picasso;public class MainActivity extends AppCompatActivity {private Context mContext = MainActivity.this;private ImageView imageView ;private ImageView imageview_ll ;private RelativeLayout mRelativeLayout ;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);setSupportActionBar(toolbar);FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);fab.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View view) {Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG).setAction("Action", null).show();}});initView();}private void initView() {imageView = (ImageView) findViewById(R.id.imageview);imageview_ll = (ImageView) findViewById(R.id.imageview_ll);mRelativeLayout = (RelativeLayout) findViewById(R.id.rl_content);Picasso.with(mContext).load(R.mipmap.img_feed_sakura).placeholder(R.drawable.img_circle_placeholder).resize(getResources().getDimensionPixelSize(R.dimen.global_menu_avatar_size),getResources().getDimensionPixelSize(R.dimen.global_menu_avatar_size)).centerCrop().transform(new CircleTransformation()).into(imageView);Bitmap bkg = BitmapFactory.decodeResource(getResources(), R.mipmap.img_feed_sakura);imageview_ll.setImageBitmap(fastblur(bkg,10));//blur(bkg,mRelativeLayout,20f);}private void blur(Bitmap bkg, View view, float radius) { //view.getMeasuredWidth() view.getMeasuredHeight()Bitmap overlay = Bitmap.createBitmap(view.getMeasuredWidth(),view.getMeasuredHeight() , Bitmap.Config.ARGB_8888);Canvas canvas = new Canvas(overlay);canvas.drawBitmap(bkg, -view.getLeft(), -view.getTop(), null);RenderScript rs = RenderScript.create(this);Allocation overlayAlloc = Allocation.createFromBitmap(rs, overlay);ScriptIntrinsicBlur blur = ScriptIntrinsicBlur.create(rs, overlayAlloc.getElement());blur.setInput(overlayAlloc);blur.setRadius(radius);blur.forEach(overlayAlloc);overlayAlloc.copyTo(overlay);view.setBackground(new BitmapDrawable(getResources(), overlay));rs.destroy();}/** This method was copied from /a/10028267/694378.* The only modifications I've made are to remove a couple of Log* statements which could slow things down slightly.*/public Bitmap fastblur(Bitmap sentBitmap, int radius) {// 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 = 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);}}
CircleTransformation.java
package com.wangjitao.bluedemotest;import android.graphics.Bitmap;import android.graphics.BitmapShader;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import com.squareup.picasso.Transformation;public class CircleTransformation implements Transformation {private static final int STROKE_WIDTH = 6;@Overridepublic Bitmap transform(Bitmap source) {int size = Math.min(source.getWidth(), source.getHeight());int x = (source.getWidth() - size) / 2;int y = (source.getHeight() - size) / 2;Bitmap squaredBitmap = Bitmap.createBitmap(source, x, y, size, size);if (squaredBitmap != source) {source.recycle();}Bitmap bitmap = Bitmap.createBitmap(size, size, source.getConfig());Canvas canvas = new Canvas(bitmap);Paint avatarPaint = new Paint();BitmapShader shader = new BitmapShader(squaredBitmap, BitmapShader.TileMode.CLAMP, BitmapShader.TileMode.CLAMP);avatarPaint.setShader(shader);Paint outlinePaint = new Paint();outlinePaint.setColor(Color.WHITE);outlinePaint.setStyle(Paint.Style.STROKE);outlinePaint.setStrokeWidth(STROKE_WIDTH);outlinePaint.setAntiAlias(true);float r = size / 2f;canvas.drawCircle(r, r, r, avatarPaint);canvas.drawCircle(r, r, r - STROKE_WIDTH / 2, outlinePaint);squaredBitmap.recycle();return bitmap;}@Overridepublic String key() {return "circleTransformation()";}}
