Java代码
//压缩图片大小 public static Bitmap compressImage(Bitmap image) { ByteArrayOutputStream baos = new ByteArrayOutputStream(); image.compress(Bitmap.CompressFormat.JPEG, 100, baos);//质量压缩方法,这里100表示不压缩,把压缩后的数据存放到baos中 int options = 100; while ( baos.toByteArray().length / 1024>100) { //循环判断如果压缩后图片是否大于100kb,大于继续压缩 baos.reset();//重置baos即清空baos image.compress(Bitmap.CompressFormat.JPEG, options, baos);//这里压缩options%,把压缩后的数据存放到baos中 options -= 10;//每次都减少10 } ByteArrayInputStream isBm = new ByteArrayInputStream(baos.toByteArray());//把压缩后的数据baos存放到ByteArrayInputStream中 Bitmap bitmap = BitmapFactory.decodeStream(isBm, null, null);//把ByteArrayInputStream数据生成图片 return bitmap; }
Java代码
/** * 将彩色图转换为灰度图 * @param img 位图 * @return 返回转换好的位图 */ public Bitmap convertGreyImg(Bitmap img) { int width = img.getWidth(); //获取位图的宽 int height = img.getHeight(); //获取位图的高 int []pixels = new int[width * height]; //通过位图的大小创建像素点数组 img.getPixels(pixels, 0, width, 0, 0, width, height); int alpha = 0xFF << 24; for(int i = 0; i < height; i++) { for(int j = 0; j < width; j++) { int grey = pixels[width * i + j]; int red = ((grey & 0x00FF0000 ) >> 16); int green = ((grey & 0x0000FF00) >> 8); int blue = (grey & 0x000000FF); grey = (int)((float) red * 0.3 + (float)green * 0.59 + (float)blue * 0.11); grey = alpha | (grey << 16) | (grey << 8) | grey; pixels[width * i + j] = grey; } } Bitmap result = Bitmap.createBitmap(width, height, Config.RGB_565); result.setPixels(pixels, 0, width, 0, 0, width, height); return result; }
将一个图片切割成多个图片
有种场景,我们想将一个图片切割成多个图片。比如我们在开发一个拼图的游戏,就首先要对图片进行切割。
以下是封装好的两个类,可以实现图片的切割。仅供参考和学习。
一个是ImagePiece类,此类保存了一个Bitmap对象和一个标识图片的顺序索引的int变量。
Java代码
import android.graphics.Bitmap; public class ImagePiece { public int index = 0; public Bitmap bitmap = null; }
一个是ImageSplitter类,有一个静态方法split,传入的参数是要切割的Bitmap对象,和横向和竖向的切割片数。比如传入的是3、3,则横竖向都切割成3片,最终会将整个图片切割成3X3=9片。
Java代码
import java.util.ArrayList; import java.util.List; import android.graphics.Bitmap; public class ImageSplitter { public static List<ImagePiece> split(Bitmap bitmap, int xPiece, int yPiece) { List<ImagePiece> pieces = new ArrayList<ImagePiece>(xPiece * yPiece); int width = bitmap.getWidth(); int height = bitmap.getHeight(); int pieceWidth = width / 3; int pieceHeight = height / 3; for (int i = 0; i < yPiece; i++) { for (int j = 0; j < xPiece; j++) { ImagePiece piece = new ImagePiece(); piece.index = j + i * xPiece; int xValue = j * pieceWidth; int yValue = i * pieceHeight; piece.bitmap = Bitmap.createBitmap(bitmap, xValue, yValue, pieceWidth, pieceHeight); pieces.add(piece); } } return pieces; } }
1、图标加灰色过滤;
2、android的图片资源默认是静态的,单实例;如果两个IM好友的头像一样,最简单的都是用的软件自带头像,有一个在线,一个离线,直接改变头像的灰度,则两个用户的头像都会变灰或者在线,答案是:Drawable.mutate()。
Java代码
Drawable mDrawable = context.getResources().getDrawable(R.drawable.face_icon); //Make this drawable mutable. //A mutable drawable is guaranteed to not share its state with any other drawable. mDrawable.mutate(); ColorMatrix cm = new ColorMatrix(); cm.setSaturation(0); ColorMatrixColorFilter cf = new ColorMatrixColorFilter(cm); mDrawable.setColorFilter(cf);
生成缩略图,抠自android launcher源码:
Java代码
/* * 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; } }
Java代码
//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); }
Java代码
//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); }
Java代码
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; } }
Java代码
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 == null ) { return null; } int w = src.getWidth(); int h = src.getHeight(); int ww = watermark.getWidth(); int wh = watermark.getHeight(); //create the new blank bitmap Bitmap newb = Bitmap.createBitmap( w, h, Config.ARGB_8888 );//创建一个新的和SRC长度宽度一样的位图 Canvas cv = new Canvas( newb ); //draw src into cv.drawBitmap( src, 0, 0, null );//在 0,0坐标开始画入src //draw watermark into cv.drawBitmap( watermark, w - ww + 5, h - wh + 5, null );//在src的右下角画入水印 //save all clip cv.save( Canvas.ALL_SAVE_FLAG );//保存 //store cv.restore();//存储 return newb; } /** 重新编码Bitmap * * @param src * 需要重新编码的Bitmap * * @param format * 编码后的格式(目前只支持png和jpeg这两种格式) * * @param quality * 重新生成后的bitmap的质量 * * @return * 返回重新生成后的bitmap */ private static Bitmap codec(Bitmap src, Bitmap.CompressFormat format, int quality) { ByteArrayOutputStream os = new ByteArrayOutputStream(); src.compress(format, quality, os); byte[] array = os.toByteArray(); return BitmapFactory.decodeByteArray(array, 0, array.length); } //Stream转换成Byte static byte[] streamToBytes(InputStream is) { ByteArrayOutputStream os = new ByteArrayOutputStream(1024); byte[] buffer = new byte[1024]; int len; try { while ((len = is.read(buffer)) >= 0) { os.write(buffer, 0, len); } } catch (java.io.IOException e) { } return os.toByteArray(); } //把View转换成Bitmap /** * 把一个View的对象转换成bitmap */ static Bitmap getViewBitmap(View v) { v.clearFocus(); v.setPressed(false); //能画缓存就返回false boolean willNotCache = v.willNotCacheDrawing(); v.setWillNotCacheDrawing(false); int color = v.getDrawingCacheBackgroundColor(); v.setDrawingCacheBackgroundColor(0); if (color != 0) { v.destroyDrawingCache(); } v.buildDrawingCache(); Bitmap cacheBitmap = v.getDrawingCache(); if (cacheBitmap == null) { Log.e(TAG, "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; }
Java代码
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);
绘制图像倒影
Java代码
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。
原文:http://gundumw100.iteye.com/blog/849729
android图片处理方法