Android - 安卓中Bitmap对象和字节流之间的相互转换（转）

转载自：代码很实用所以转载过来，又因为转载的也是别人转载的文章，所以出处不知道，请见谅！

android 将图片内容解析成字节数组；将字节数组转换为ImageView可调用的Bitmap对象；图片缩放；把字节数组保存为一个文件；把Bitmap转Byte

  1 import java.io.BufferedOutputStream;  
  2 import java.io.ByteArrayOutputStream;  
  3 import java.io.File;  
  4 import java.io.FileOutputStream;  
  5 import java.io.IOException;  
  6 import java.io.InputStream;  
  7   
  8 import android.graphics.Bitmap;  
  9 import android.graphics.BitmapFactory;  
 10 import android.graphics.Matrix;  
 11   
 12 public class ImageDispose {  
 13       
 14     /** 
 15      * @param 将图片内容解析成字节数组 
 16      * @param inStream 
 17      * @return byte[] 
 18      * @throws Exception 
 19      */  
 20     public static byte[] readStream(InputStream inStream) throws Exception {  
 21         byte[] buffer = new byte[1024];  
 22         int len = -1;  
 23         ByteArrayOutputStream outStream = new ByteArrayOutputStream();  
 24         while ((len = inStream.read(buffer)) != -1) {  
 25             outStream.write(buffer, 0, len);  
 26         }  
 27         byte[] data = outStream.toByteArray();  
 28         outStream.close();  
 29         inStream.close();  
 30         return data;  
 31     }  
 32 
 33     /** 
 34      * @param 将字节数组转换为ImageView可调用的Bitmap对象 
 35      * @param bytes 
 36      * @param opts 
 37      * @return Bitmap 
 38      */  
 39     public static Bitmap getPicFromBytes(byte[] bytes,  
 40             BitmapFactory.Options opts) {  
 41         if (bytes != null)  
 42             if (opts != null)  
 43                 return BitmapFactory.decodeByteArray(bytes, 0, bytes.length,  
 44                         opts);  
 45             else  
 46                 return BitmapFactory.decodeByteArray(bytes, 0, bytes.length);  
 47         return null;  
 48     }  
 49 
 50     /** 
 51      * @param 图片缩放 
 52      * @param bitmap 对象 
 53      * @param w 要缩放的宽度 
 54      * @param h 要缩放的高度 
 55      * @return newBmp 新 Bitmap对象 
 56      */  
 57     public static Bitmap zoomBitmap(Bitmap bitmap, int w, int h){  
 58         int width = bitmap.getWidth();  
 59         int height = bitmap.getHeight();  
 60         Matrix matrix = new Matrix();  
 61         float scaleWidth = ((float) w / width);  
 62         float scaleHeight = ((float) h / height);  
 63         matrix.postScale(scaleWidth, scaleHeight);  
 64         Bitmap newBmp = Bitmap.createBitmap(bitmap, 0, 0, width, height,  
 65                 matrix, true);  
 66         return newBmp;  
 67     }  
 68       
 69     /** 
 70      * 把Bitmap转Byte 
 71      */  
 72     public static byte[] Bitmap2Bytes(Bitmap bm){  
 73         ByteArrayOutputStream baos = new ByteArrayOutputStream();  
 74         bm.compress(Bitmap.CompressFormat.PNG, 100, baos);  
 75         return baos.toByteArray();  
 76     }  
 77 
 78     /** 
 79      * 把字节数组保存为一个文件 
 80      */  
 81     public static File getFileFromBytes(byte[] b, String outputFile) {  
 82         BufferedOutputStream stream = null;  
 83         File file = null;  
 84         try {  
 85             file = new File(outputFile);  
 86             FileOutputStream fstream = new FileOutputStream(file);  
 87             stream = new BufferedOutputStream(fstream);  
 88             stream.write(b);  
 89         } catch (Exception e) {  
 90             e.printStackTrace();  
 91         } finally {  
 92             if (stream != null) {  
 93                 try {  
 94                     stream.close();  
 95                 } catch (IOException e1) {  
 96                     e1.printStackTrace();  
 97                 }  
 98             }  
 99         }  
100         return file;  
101     }  
102 }

 

posted @ 2019-04-03 10:07  Citrusliu  阅读(7276)  评论(0)  编辑  收藏  举报