图片压缩保存读取操作

1. //对图片进行压缩
2. BitmapFactory.Optionsoptions=newBitmapFactory.Options();
3. options.inJustDecodeBounds=true;
4. //获取这个图片的宽和高
5. Bitmapbitmap=BitmapFactory.decodeFile("/sdcard/dcim/Camera/hello.jpg",options);//此时返回bm为空
6. options.inJustDecodeBounds=false;
7. //计算缩放比
8. intbe=(int)(options.outHeight/(float)200);
9. if(be<=0)
10. be=1;
11. options.inSampleSize=be;
12. //重新读入图片，注意这次要把options.inJustDecodeBounds设为false哦
13. bitmap=BitmapFactory.decodeFile("/sdcard/dcim/Camera/hello.jpg",options);
14. intw=bitmap.getWidth();
15. inth=bitmap.getHeight();
16. System.out.println(w+""+h);
17. myImageView.setImageBitmap(bitmap);
20. //保存入sdCard
21. Filefile2=newFile("/sdcard/dcim/Camera/test.jpg");
22. try{
23. FileOutputStreamout=newFileOutputStream(file2);
24. if(bitmap.compress(Bitmap.CompressFormat.JPEG,100,out)){
25. out.flush();
26. out.close();
27. }
28. }catch(Exceptione){
29. //TODO:handleexception
30. }

1. //读取sd卡
2. Filefile=newFile("/sdcard/dcim/Camera/test.jpg");
3. intmaxBufferSize=16*1024;
5. intlen=0;
6. ByteArrayOutputStreamoutStream=newByteArrayOutputStream();
7. BufferedInputStreambufferedInputStream;
8. try{
9. bufferedInputStream=newBufferedInputStream(newFileInputStream(file));
10. intbytesAvailable=bufferedInputStream.available();
11. intbufferSize=Math.min(bytesAvailable,maxBufferSize);
12. byte[]buffer=newbyte[bufferSize];
13. while((len=bufferedInputStream.read(buffer))!=-1)
14. {
15. outStream.write(buffer,0,bufferSize);
16. }
17. data=outStream.toByteArray();
18. outStream.close();
19. bufferedInputStream.close();
21. }catch(FileNotFoundExceptione){
22. e.printStackTrace();
23. }catch(IOExceptione){
24. e.printStackTrace();
25. }