收集了很多bitmap相关的处理方法，几乎全部应用在项目中，所以特记录下！
package com.tmacsky.utils;import java.io.ByteArrayOutputStream;import java.io.IOException;import android.content.Context;import android.content.res.Resources;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Canvas;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.drawable.BitmapDrawable;import android.graphics.drawable.Drawable;import android.view.View;import android.view.View.MeasureSpec;public class ImageUtils { //--->bitmap相关 //参考网站http://www.cnblogs.com/fighter/archive/2012/02/20/android-bitmap-drawable.html // 见博客：http://blog.sina.com.cn/s/blog_afb547c60101j7qn.html /** * View转成bitmap * @param view * @return */ public static Bitmap convertViewToBitmap(View view) { view.setDrawingCacheEnabled(true); view.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED)); view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight()); view.buildDrawingCache(); return view.getDrawingCache(); } /** * 缩放Drawable * @param drawable * @param w 缩放后需要的宽度 * @param h 缩放后需要的高度 * @return */ public static Drawable zoomDrawable(Drawable drawable, int w, int h) { int width = drawable.getIntrinsicWidth(); int height = drawable.getIntrinsicHeight(); // drawable转换成bitmap Bitmap oldbmp = drawableToBitmap(drawable); // 创建操作图片用的Matrix对象 Matrix matrix = new Matrix(); // 计算缩放比例 float sx = ((float) w / width); float sy = ((float) h / height); // 设置缩放比例 matrix.postScale(sx, sy); // 建立新的bitmap，其内容是对原bitmap的缩放后的图 Bitmap newbmp = Bitmap.createBitmap(oldbmp, 0, 0, width, height, matrix, true); return new BitmapDrawable(newbmp); } /** * 缩放bitmap * @param oldBitmap 输入bitmap * @param newWidth * @param newHeight * @return */ public static Bitmap zoomBitmap(Bitmap oldBitmap, int newWidth, int newHeight) { // 获得图片的宽高 int width = oldBitmap.getWidth(); int height = oldBitmap.getHeight(); // 计算缩放比例 float scaleWidth = ((float) newWidth) / width; float scaleHeight = ((float) newHeight) / height; // 取得想要缩放的matrix参数 Matrix matrix = new Matrix(); matrix.postScale(scaleWidth, scaleHeight); // 得到新的图片 Bitmap newbm = Bitmap.createBitmap(oldBitmap, 0, 0, width, height, matrix, true); return newbm; } /** * 缩放网络图片 依赖于zoomBitmap * @param img * @param newWidth * @param newHeight * @return */ public static Bitmap zoomImg(String img, int newWidth, int newHeight) { // 图片源 Bitmap bm = BitmapFactory.decodeFile(img); if (null != bm) { return zoomBitmap(bm, newWidth, newHeight); } return null; } /** * 缩放网络图片 依赖于zoomBitmap * @param context * @param img * @param newWidth * @param newHeight * @return */ public static Bitmap zoomImg(Context context, String img, int newWidth, int newHeight) { // 图片源 try { Bitmap bm = BitmapFactory.decodeStream(context.getAssets() .open(img)); if (null != bm) { return zoomBitmap(bm, newWidth, newHeight); } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } return null; } /** * 判断bitmap是否存在 * @param bitmap * @return */ public static boolean bitmapAvailable(Bitmap bitmap) { return bitmap != null && bitmap.getWidth() > 0 && bitmap.getHeight() > 0; } /** * drawable 转成bitmap * @param drawable * @return */ public static Bitmap drawableToBitmap(Drawable drawable) { // 取 drawable 的长宽 int w = drawable.getIntrinsicWidth(); int h = drawable.getIntrinsicHeight(); // 取 drawable 的颜色格式 Bitmap.Config config = drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888 : Bitmap.Config.RGB_565; // 建立对应 bitmap Bitmap bitmap = Bitmap.createBitmap(w, h, config); // 建立对应 bitmap 的画布 Canvas canvas = new Canvas(bitmap); drawable.setBounds(0, 0, w, h); // 把 drawable 内容画到画布中 drawable.draw(canvas); return bitmap; } /** * Bitmap转换成Drawable * @param context * @param bitmap * @return */ public static Drawable bitmapToDrawable(Context context,Bitmap bitmap){ //因为BtimapDrawable是Drawable的子类，最终直接使用bd对象即可。 BitmapDrawable bd= new BitmapDrawable(context.getResources(), bitmap); return bd; } /** * 从资源中获取Bitmap * @param context * @param req R.drawable.icon(eg.) * @return */ public Bitmap getBitmapFromResources(Context context,int req){ Resources res = context.getResources(); Bitmap bmp = BitmapFactory.decodeResource(res, req); return bmp; } /** * Byte[] -> Bitmap的转换 */ public Bitmap Bytes2Bimap(byte[] b) { if (b.length != 0) { return BitmapFactory.decodeByteArray(b, 0, b.length); } else { return null; } } /** * Bitmap->Byte[]的转换 * @param bm * @return */ public byte[] Bitmap2Bytes(Bitmap bm) { ByteArrayOutputStream baos = new ByteArrayOutputStream(); bm.compress(Bitmap.CompressFormat.PNG, 100, baos); return baos.toByteArray(); } /** * 获取圆角图片 * @param bitmap * @param roundPx 圆角的弧度 * @return */ public static Bitmap getRoundedCornerBitmap(Bitmap bitmap, float roundPx) { int w = bitmap.getWidth(); int h = bitmap.getHeight(); Bitmap output = Bitmap.createBitmap(w, h, Config.ARGB_8888); Canvas canvas = new Canvas(output); final int color = 0xff424242; final Paint paint = new Paint(); final Rect rect = new Rect(0, 0, w, h); 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; }}