（转）Android中Bitmap对象和字节流之间的相互转换

亦凉 2023-08-17 15:27 128阅读 0赞

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 }

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！

转载于:https://www.cnblogs.com/citrus/p/10647044.html