/*  * Copyright (C) 2008 The Android Open Source Project  *  * Licensed under the Apache License, Version 2.0 (the "License");  * you may not use this file except in compliance with the License.  * You may obtain a copy of the License at  *  *      http://www.apache.org/licenses/LICENSE-2.0  *  * Unless required by applicable law or agreed to in writing, software  * distributed under the License is distributed on an "AS IS" BASIS,  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  * See the License for the specific language governing permissions and  * limitations under the License.  */    package com.android.launcher;    import android.graphics.drawable.BitmapDrawable;  import android.graphics.drawable.Drawable;  import android.graphics.drawable.PaintDrawable;  import android.graphics.Bitmap;  import android.graphics.PixelFormat;  import android.graphics.Canvas;  import android.graphics.PaintFlagsDrawFilter;  import android.graphics.Paint;  import android.graphics.Rect;  import android.content.res.Resources;  import android.content.Context;    /**  * Various utilities shared amongst the Launcher‘s classes.  */  final class Utilities {      private static int sIconWidth = -1;      private static int sIconHeight = -1;        private static final Paint sPaint = new Paint();      private static final Rect sBounds = new Rect();      private static final Rect sOldBounds = new Rect();      private static Canvas sCanvas = new Canvas();        static {          sCanvas.setDrawFilter(new PaintFlagsDrawFilter(Paint.DITHER_FLAG,                  Paint.FILTER_BITMAP_FLAG));      }        /**      * Returns a Drawable representing the thumbnail of the specified Drawable.      * The size of the thumbnail is defined by the dimension      * android.R.dimen.launcher_application_icon_size.      *      * This method is not thread-safe and should be invoked on the UI thread only.      *      * @param icon The icon to get a thumbnail of.      * @param context The application‘s context.      *      * @return A thumbnail for the specified icon or the icon itself if the      *         thumbnail could not be created.       */      static Drawable createIconThumbnail(Drawable icon, Context context) {          if (sIconWidth == -1) {              final Resources resources = context.getResources();              sIconWidth = sIconHeight = (int) resources.getDimension(android.R.dimen.app_icon_size);          }            int width = sIconWidth;          int height = sIconHeight;            float scale = 1.0f;          if (icon instanceof PaintDrawable) {              PaintDrawable painter = (PaintDrawable) icon;              painter.setIntrinsicWidth(width);              painter.setIntrinsicHeight(height);          } else if (icon instanceof BitmapDrawable) {              // Ensure the bitmap has a density.              BitmapDrawable bitmapDrawable = (BitmapDrawable) icon;              Bitmap bitmap = bitmapDrawable.getBitmap();              if (bitmap.getDensity() == Bitmap.DENSITY_NONE) {                  bitmapDrawable.setTargetDensity(context.getResources().getDisplayMetrics());              }          }          int iconWidth = icon.getIntrinsicWidth();          int iconHeight = icon.getIntrinsicHeight();            if (width > 0 && height > 0) {              if (width < iconWidth || height < iconHeight || scale != 1.0f) {                  final float ratio = (float) iconWidth / iconHeight;                    if (iconWidth > iconHeight) {                      height = (int) (width / ratio);                  } else if (iconHeight > iconWidth) {                      width = (int) (height * ratio);                  }                    final Bitmap.Config c = icon.getOpacity() != PixelFormat.OPAQUE ?                              Bitmap.Config.ARGB_8888 : Bitmap.Config.RGB_565;                  final Bitmap thumb = Bitmap.createBitmap(sIconWidth, sIconHeight, c);                  final Canvas canvas = sCanvas;                  canvas.setBitmap(thumb);                  // Copy the old bounds to restore them later                  // If we were to do oldBounds = icon.getBounds(),                  // the call to setBounds() that follows would                  // change the same instance and we would lose the                  // old bounds                  sOldBounds.set(icon.getBounds());                  final int x = (sIconWidth - width) / 2;                  final int y = (sIconHeight - height) / 2;                  icon.setBounds(x, y, x + width, y + height);                  icon.draw(canvas);                  icon.setBounds(sOldBounds);                  icon = new FastBitmapDrawable(thumb);              } else if (iconWidth < width && iconHeight < height) {                  final Bitmap.Config c = Bitmap.Config.ARGB_8888;                  final Bitmap thumb = Bitmap.createBitmap(sIconWidth, sIconHeight, c);                  final Canvas canvas = sCanvas;                  canvas.setBitmap(thumb);                  sOldBounds.set(icon.getBounds());                  final int x = (width - iconWidth) / 2;                  final int y = (height - iconHeight) / 2;                  icon.setBounds(x, y, x + iconWidth, y + iconHeight);                  icon.draw(canvas);                  icon.setBounds(sOldBounds);                  icon = new FastBitmapDrawable(thumb);              }          }            return icon;      }        /**      * Returns a Bitmap representing the thumbnail of the specified Bitmap.      * The size of the thumbnail is defined by the dimension      * android.R.dimen.launcher_application_icon_size.      *      * This method is not thread-safe and should be invoked on the UI thread only.      *      * @param bitmap The bitmap to get a thumbnail of.      * @param context The application‘s context.      *      * @return A thumbnail for the specified bitmap or the bitmap itself if the      *         thumbnail could not be created.      */      static Bitmap createBitmapThumbnail(Bitmap bitmap, Context context) {          if (sIconWidth == -1) {              final Resources resources = context.getResources();              sIconWidth = sIconHeight = (int) resources.getDimension(                      android.R.dimen.app_icon_size);          }            int width = sIconWidth;          int height = sIconHeight;            final int bitmapWidth = bitmap.getWidth();          final int bitmapHeight = bitmap.getHeight();            if (width > 0 && height > 0) {              if (width < bitmapWidth || height < bitmapHeight) {                  final float ratio = (float) bitmapWidth / bitmapHeight;                        if (bitmapWidth > bitmapHeight) {                      height = (int) (width / ratio);                  } else if (bitmapHeight > bitmapWidth) {                      width = (int) (height * ratio);                  }                        final Bitmap.Config c = (width == sIconWidth && height == sIconHeight) ?                          bitmap.getConfig() : Bitmap.Config.ARGB_8888;                  final Bitmap thumb = Bitmap.createBitmap(sIconWidth, sIconHeight, c);                  final Canvas canvas = sCanvas;                  final Paint paint = sPaint;                  canvas.setBitmap(thumb);                  paint.setDither(false);                  paint.setFilterBitmap(true);                  sBounds.set((sIconWidth - width) / 2, (sIconHeight - height) / 2, width, height);                  sOldBounds.set(0, 0, bitmapWidth, bitmapHeight);                  canvas.drawBitmap(bitmap, sOldBounds, sBounds, paint);                  return thumb;              } else if (bitmapWidth < width || bitmapHeight < height) {                  final Bitmap.Config c = Bitmap.Config.ARGB_8888;                  final Bitmap thumb = Bitmap.createBitmap(sIconWidth, sIconHeight, c);                  final Canvas canvas = sCanvas;                  final Paint paint = sPaint;                  canvas.setBitmap(thumb);                  paint.setDither(false);                  paint.setFilterBitmap(true);                  canvas.drawBitmap(bitmap, (sIconWidth - bitmapWidth) / 2,                          (sIconHeight - bitmapHeight) / 2, paint);                  return thumb;              }          }            return bitmap;      }  } 

    //Android Matrix类实现镜像方法      public void drawRegion(Image image_src,            int x_src, int y_src,            int width, int height,            int transform,            int x_dest, int y_dest,            int anchor){            if((anchor&VCENTER) != 0){            y_dest -= height/2;            }else if((anchor&BOTTOM) != 0){            y_dest -= height;            }            if((anchor&RIGHT) != 0){            x_dest -= width;            }else if((anchor&HCENTER) != 0){            x_dest -= width/2;            }            Bitmap newMap = Bitmap.createBitmap(image_src.getBitmap(), x_src, y_src, width, height);            Matrix mMatrix = new Matrix();            Matrix temp = new Matrix();            Matrix temp2 = new Matrix();            float[] mirrorY = {            -1, 0, 0,      0, 1, 0,      0, 0, 1            };            temp.setValues(mirrorY);            switch(transform){            case Sprite.TRANS_NONE:            break;            case Sprite.TRANS_ROT90:            mMatrix.setRotate(90,width/2, height/2);            break;            case Sprite.TRANS_ROT180:            mMatrix.setRotate(180,width/2, height/2);            break;            case Sprite.TRANS_ROT270:            mMatrix.setRotate(270,width/2, height/2);            break;            case Sprite.TRANS_MIRROR:            mMatrix.postConcat(temp);            break;            case Sprite.TRANS_MIRROR_ROT90:            mMatrix.postConcat(temp);            mMatrix.setRotate(90,width/2, height/2);            break;            case Sprite.TRANS_MIRROR_ROT180:            mMatrix.postConcat(temp);            mMatrix.setRotate(180,width/2, height/2);            break;            case Sprite.TRANS_MIRROR_ROT270:            mMatrix.postConcat(temp);            mMatrix.setRotate(270,width/2, height/2);            break;            }            mMatrix.setTranslate(x_dest, y_dest);            canvas.drawBitmap(newMap, mMatrix, mPaint);            }  

    //图片Url保存为位图并进行缩放操作      //通过传入图片url获取位图方法      public Bitmap returnBitMap(String url) {              URL myFileUrl = null;              Bitmap bitmap = null;              try {                  myFileUrl = new URL(url);              } catch (MalformedURLException e) {                  e.printStackTrace();              }              try {                  HttpURLConnection conn = (HttpURLConnection) myFileUrl                          .openConnection();                  conn.setDoInput(true);                  conn.connect();                  InputStream is = conn.getInputStream();                  bitmap = BitmapFactory.decodeStream(is);                  is.close();              } catch (IOException e) {                  e.printStackTrace();              }              Log.v(tag, bitmap.toString());                    return bitmap;          }      //通过传入位图,新的宽.高比进行位图的缩放操作      public static Drawable resizeImage(Bitmap bitmap, int w, int h) {                    // load the origial Bitmap              Bitmap BitmapOrg = bitmap;                    int width = BitmapOrg.getWidth();              int height = BitmapOrg.getHeight();              int newWidth = w;              int newHeight = h;                    Log.v(tag, String.valueOf(width));              Log.v(tag, String.valueOf(height));                    Log.v(tag, String.valueOf(newWidth));              Log.v(tag, String.valueOf(newHeight));                    // calculate the scale              float scaleWidth = ((float) newWidth) / width;              float scaleHeight = ((float) newHeight) / height;                    // create a matrix for the manipulation              Matrix matrix = new Matrix();              // resize the Bitmap              matrix.postScale(scaleWidth, scaleHeight);              // if you want to rotate the Bitmap              // matrix.postRotate(45);                    // recreate the new Bitmap              Bitmap resizedBitmap = Bitmap.createBitmap(BitmapOrg, 0, 0, width,                      height, matrix, true);                    // make a Drawable from Bitmap to allow to set the Bitmap              // to the ImageView, ImageButton or what ever              return new BitmapDrawable(resizedBitmap);                }  

    1.图片加载方法，方便用户加载图片      /***     * 加载本地图片     * @param context：主运行函数实例     * @param bitAdress：图片地址，一般指向R下的drawable目录     * @return     */      public final Bitmap CreatImage(Context context, int bitAdress) {      Bitmap bitmaptemp = null;      bitmaptemp = BitmapFactory.decodeResource(context.getResources(),      bitAdress);      return bitmaptemp;      }      2.图片平均分割方法，将大图平均分割为N行N列，方便用户使用      /***     * 图片分割     *     * @param g     * ：画布     * @param paint     * ：画笔     * @param imgBit     * ：图片     * @param x     * ：X轴起点坐标     * @param y     * ：Y轴起点坐标     * @param w     * ：单一图片的宽度     * @param h     * ：单一图片的高度     * @param line     * ：第几列     * @param row     * ：第几行     */      public final void cuteImage(Canvas g, Paint paint, Bitmap imgBit, int x,      int y, int w, int h, int line, int row) {      g.clipRect(x, y, x + w, h + y);      g.drawBitmap(imgBit, x – line * w, y – row * h, paint);      g.restore();      }      3.图片缩放，对当前图片进行缩放处理      /***     * 图片的缩放方法     *     * @param bgimage     * ：源图片资源     * @param newWidth     * ：缩放后宽度     * @param newHeight     * ：缩放后高度     * @return     */      public Bitmap zoomImage(Bitmap bgimage, int newWidth, int newHeight) {      // 获取这个图片的宽和高      int width = bgimage.getWidth();      int height = bgimage.getHeight();      // 创建操作图片用的matrix对象      Matrix matrix = new Matrix();      // 计算缩放率，新尺寸除原始尺寸      float scaleWidth = ((float) newWidth) / width;      float scaleHeight = ((float) newHeight) / height;      // 缩放图片动作      matrix.postScale(scaleWidth, scaleHeight);      Bitmap bitmap = Bitmap.createBitmap(bgimage, 0, 0, width, height,      matrix, true);      return bitmap;      }      4.绘制带有边框的文字，一般在游戏中起文字的美化作用      /***     * 绘制带有边框的文字     *     * @param strMsg     * ：绘制内容     * @param g     * ：画布     * @param paint     * ：画笔     * @param setx     * ：：X轴起始坐标     * @param sety     * ：Y轴的起始坐标     * @param fg     * ：前景色     * @param bg     * ：背景色     */      public void drawText(String strMsg, Canvas g, Paint paint, int setx,      int sety, int fg, int bg) {      paint.setColor(bg);      g.drawText(strMsg, setx + 1, sety, paint);      g.drawText(strMsg, setx, sety – 1, paint);      g.drawText(strMsg, setx, sety + 1, paint);      g.drawText(strMsg, setx – 1, sety, paint);      paint.setColor(fg);      g.drawText(strMsg, setx, sety, paint);      g.restore();      }      5.Android 图片透明度处理代码      /**     * 图片透明度处理     *     * @param sourceImg     *            原始图片     * @param number     *            透明度     * @return     */      public static Bitmap setAlpha(Bitmap sourceImg, int number) {      int[] argb = new int[sourceImg.getWidth() * sourceImg.getHeight()];      sourceImg.getPixels(argb, 0, sourceImg.getWidth(), 0, 0,sourceImg.getWidth(), sourceImg.getHeight());// 获得图片的ARGB值      number = number * 255 / 100;      for (int i = 0; i < argb.length; i++) {      argb = (number << 24) | (argb & 0×00FFFFFF);// 修改最高2位的值      }      sourceImg = Bitmap.createBitmap(argb, sourceImg.getWidth(), sourceImg.getHeight(), Config.ARGB_8888);      return sourceImg;      }      6.图片翻转      Resources res = this.getContext().getResources();      img = BitmapFactory.decodeResource(res, R.drawable.slogo);      Matrix matrix = new Matrix();      matrix.postRotate(90);        /*翻转90度*/      int width = img.getWidth();      int height = img.getHeight();      r_img = Bitmap.createBitmap(img, 0, 0, width, height, matrix, true);  Java代码  收藏代码    import android.graphics.Bitmap;      import android.graphics.Canvas;      import android.graphics.LinearGradient;      import android.graphics.Matrix;      import android.graphics.Paint;      import android.graphics.PixelFormat;      import android.graphics.PorterDuffXfermode;      import android.graphics.Rect;      import android.graphics.RectF;      import android.graphics.Bitmap.Config;      import android.graphics.PorterDuff.Mode;      import android.graphics.Shader.TileMode;      import android.graphics.drawable.Drawable;      /**     *      * @author superdev     * @version 1.0     *     */      public class ImageUtil {            /**     * 放大缩小图片     */      public static Bitmap zoomBitmap(Bitmap bitmap, int w, int h) {         int width = bitmap.getWidth();         int height = bitmap.getHeight();         Matrix matrix = new Matrix();         float scaleWidht = ((float) w / width);         float scaleHeight = ((float) h / height);         matrix.postScale(scaleWidht, scaleHeight);         Bitmap newbmp = Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true);         return newbmp;      }            /**     * 将Drawable转化为Bitmap     */      public static Bitmap drawableToBitmap(Drawable drawable) {         int width = drawable.getIntrinsicWidth();         int height = drawable.getIntrinsicHeight();         Bitmap bitmap = Bitmap.createBitmap(width, height, drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888 : Bitmap.Config.RGB_565);         Canvas canvas = new Canvas(bitmap);         drawable.setBounds(0, 0, width, height);         drawable.draw(canvas);         return bitmap;            }            /**     * 获得圆角图片的方法     */      public static Bitmap getRoundedCornerBitmap(Bitmap bitmap, float roundPx) {               Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Config.ARGB_8888);         Canvas canvas = new Canvas(output);               final int color = 0xff424242;         final Paint paint = new Paint();         final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());         final RectF rectF = new RectF(rect);               paint.setAntiAlias(true);         canvas.drawARGB(0, 0, 0, 0);         paint.setColor(color);         canvas.drawRoundRect(rectF, roundPx, roundPx, paint);               paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));         canvas.drawBitmap(bitmap, rect, rect, paint);               return output;      }            /**     * 获得带倒影的图片方法     */      public static Bitmap createReflectionImageWithOrigin(Bitmap bitmap) {         final int reflectionGap = 4;         int width = bitmap.getWidth();         int height = bitmap.getHeight();               Matrix matrix = new Matrix();         matrix.preScale(1, -1);               Bitmap reflectionImage = Bitmap.createBitmap(bitmap, 0, height / 2, width, height / 2, matrix, false);               Bitmap bitmapWithReflection = Bitmap.createBitmap(width, (height + height / 2), Config.ARGB_8888);               Canvas canvas = new Canvas(bitmapWithReflection);         canvas.drawBitmap(bitmap, 0, 0, null);         Paint deafalutPaint = new Paint();         canvas.drawRect(0, height, width, height + reflectionGap, deafalutPaint);               canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);               Paint paint = new Paint();         LinearGradient shader = new LinearGradient(0, bitmap.getHeight(), 0, bitmapWithReflection.getHeight() + reflectionGap, 0x70ffffff, 0x00ffffff, TileMode.CLAMP);         paint.setShader(shader);         // Set the Transfer mode to be porter duff and destination in         paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));         // Draw a rectangle using the paint with our linear gradient         canvas.drawRect(0, height, width, bitmapWithReflection.getHeight() + reflectionGap, paint);         return bitmapWithReflection;      }      } 

    private byte[] Bitmap2Bytes(Bitmap bm){         ByteArrayOutputStream baos = new ByteArrayOutputStream();         bm.compress(Bitmap.CompressFormat.PNG, 100, baos);         return baos.toByteArray();      }      private Bitmap Bytes2Bimap(byte[] b){                  if(b.length!=0){                      return BitmapFactory.decodeByteArray(b, 0, b.length);                  }                  else {                      return null;                  }            }             /**          * create the bitmap from a byte array          *生成水印图片          * @param src the bitmap object you want proecss          * @param watermark the water mark above the src          * @return return a bitmap object ,if paramter‘s length is 0,return null          */          private Bitmap createBitmap( Bitmap src, Bitmap watermark )          {              String tag = "createBitmap";              Log.d( tag, "create a new bitmap" );              if( src =http://www.mamicode.com/= null )  "failed getViewBitmap(" + v + ")", new RuntimeException());                  return null;              }              Bitmap bitmap = Bitmap.createBitmap(cacheBitmap);              // Restore the view              v.destroyDrawingCache();              v.setWillNotCacheDrawing(willNotCache);              v.setDrawingCacheBackgroundColor(color);              return bitmap;          }  

读取raw资源文件中的mp3文件，然后通过音乐播放器播放：        /**      * 把mp3文件写入卡      *       * @param fileName      *             输出的文件名（全路径）      * @param context          *             context对象      */      private void writeMP3ToSDcard(String fileName, Context context) {          byte[] buffer = new byte[1024 * 8];          int read;          BufferedInputStream bin = new BufferedInputStream(context.getResources().openRawResource(R.raw.ring));          try {              BufferedOutputStream bout = new BufferedOutputStream(new FileOutputStream(fileName));              while ((read = bin.read(buffer)) > -1) {                  bout.write(buffer, 0, read);              }              bout.flush();              bout.close();              bin.close();          } catch (FileNotFoundException e) {              e.printStackTrace();          } catch (IOException e) {              e.printStackTrace();          }      }      Intent intent = new Intent();  intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);  intent.setAction(android.content.Intent.ACTION_VIEW);  intent.setDataAndType(Uri.fromFile(newFile("XXXXmp3的文件全路径")),"audio/*");  startActivity(intent); 

private void    _Init()     {       m_paint = new Paint(Paint.ANTI_ALIAS_FLAG);       LinearGradient lg = new LinearGradient(         0, 0, 0, m_nShadowH,          0xB0FFFFFF, 0x00000000,         Shader.TileMode.CLAMP);       m_paint.setShader(lg);       m_paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.MULTIPLY));     }         @Override protected void      onDraw(Canvas canvas)     {       super.onDraw(canvas);           int nX = 0;       int nY = 20;           _DrawNormalImg(canvas, nX, nY);       _DrawMirror(canvas, nX, nY);     }          private void    _DrawNormalImg(Canvas canvas, int nX, int nY)     {       canvas.save(Canvas.MATRIX_SAVE_FLAG);       canvas.translate(nX, nY);          m_dw.draw(canvas);       canvas.restore();     }         private void    _DrawMirror(Canvas canvas, int nX, int nY)     {       int nW = m_dw.getIntrinsicWidth();       int nH = m_dw.getIntrinsicHeight();           ///////////////////////////////////       //draw mirror image       canvas.save(Canvas.MATRIX_SAVE_FLAG);       canvas.scale(1.0f, -1.0f);       canvas.translate(nX, -(nY + nH * 2));       canvas.clipRect(0, nH, nW, nH - m_nShadowH);       m_dw.draw(canvas);       canvas.restore();           //////////////////////////////       //draw mask       canvas.save();       canvas.translate(nX, nY + nH);       canvas.drawRect(0, 0, nW, m_nShadowH, m_paint);       canvas.restore();     }  

Android 繪圖座標體系預設的原點在左上角，X 軸往右是越來越大的正值，而 Y 軸往下，則是越來越大的正值。要畫出垂直翻轉的圖片，其實也就是要垂直翻轉整個繪圖座標體系。在 Android 中，要如何做？答案就是 canvas.scale(1.0f, -1.0f)。很簡單吧，沒想到給 scale() 函式一個負值，就可以翻轉相對應的軸。
在 Photoshop 中，做鏡像特效的第二步是要對這翻轉的圖片，加個由灰到黑的漸層 mask。
在 Android 中，要畫漸層色，那就一定得用 LinearGradient 這個類別。至於要對背景圖加上個 mask，就請參考一下 Paint 的 setXfermode() 函式。_Init() 這個函式，就是負責生成一個由灰到黑漸層 mask 的 m_paint 物件。