Android之Bitmap使用心得(持续更新)

因为此代码里面有解释，因此直接上代码：

 
  public  
  class ChangeBitmapPixel  
  extends Activity { 
  
     
  private Button btn; 
  
     
  private Bitmap photo; 
  
     
  private ImageView image; 
  
    FileOutputStream fos =  
  null; 
  
    BufferedOutputStream bos =  
  null; 
  
     
  private ByteArrayOutputStream baos; 
  
    @Override 
  
     
  public  
  void onCreate(Bundle savedInstanceState) { 
  
         
  super.onCreate(savedInstanceState); 
  
        setContentView(R.layout.main); 
  
         
  
        image = (ImageView) findViewById(R.id.image); 
  
        btn = (Button) findViewById(R.id.button); 
  
        btn.setOnClickListener( 
  new OnClickListener(){ 
  
 
  
            @Override 
  
             
  public  
  void onClick(View v) { 
  
                 
  // 
   TODO Auto-generated method stub 
  
                Intent i =  
  new Intent("android.media.action.IMAGE_CAPTURE"); 
  
                 
  // 
  如果使用下面注释的代码，将不返回数据给Intent
 
  // 
                  i.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(new File(Environment
 
  // 
                          .getExternalStorageDirectory(),"pic.jpg")));
                 
  // 
  启动摄像头并且在拍摄后返回 
  
                startActivityForResult(i, 10); 
  
            }}); 
  
         
  
    } 
  
    @Override 
  
     
  protected  
  void onActivityResult( 
  int requestCode,  
  int resultCode, Intent data) { 
  
         
  // 
  两种读取文件的方法 
  
         Uri uri = data.getData(); 
  
          
  if (uri !=  
  null) { 
  
             System.out.println("uri不为空"); 
  
             photo = BitmapFactory.decodeFile(uri.getPath()); 
  
             System.out.println("uri:"+photo); 
  
         } 
  
          
  
           
  if (photo ==  
  null) { 
  
              Bundle bundle = data.getExtras(); 
  
               
  if (bundle !=  
  null) { 
  
                  photo = (Bitmap) bundle.get("data"); 
  
                  image.setImageBitmap(photo); 
  
                   
  // 
  保存照片 
  
                  savePic(photo); 
  
                  System.out.println("photo:"+photo); 
  
              }  
  else { 
  
                  Toast.makeText(ChangeBitmapPixel. 
  this, 
  
                          "为空", 
  
                          Toast.LENGTH_LONG).show(); 
  
                   
  return; 
  
              } 
  
          } 
  
         
  super.onActivityResult(requestCode, resultCode, data); 
  
        } 
  
     
  public  
  void savePic(Bitmap bitmap){ 
  
         
  // 
  使用此流读取 
  
        baos =  
  new ByteArrayOutputStream(); 
  
         
  // 
  第二个参数影响的是图片的质量，但是图片的宽度与高度是不会受影响滴 
  
        bitmap.compress(Bitmap.CompressFormat.JPEG, 80, baos); 
  
         
  // 
  这个函数能够设定图片的宽度与高度
         
  // 
  Bitmap map = Bitmap.createScaledBitmap(bitmap, 400, 400, true);
         
  // 
  把数据转为为字节数组 
  
         
  byte[] byteArray = baos.toByteArray(); 
  
         
  try { 
  
            fos =  
  new FileOutputStream(Environment.getExternalStorageDirectory()+"pic.jpg"); 
  
            bos =  
  new BufferedOutputStream(fos); 
  
            bos.write(byteArray); 
  
        }  
  catch (FileNotFoundException e) { 
  
             
  // 
   TODO Auto-generated catch block 
  
            e.printStackTrace(); 
  
        }  
  catch (IOException e) { 
  
             
  // 
   TODO Auto-generated catch block 
  
            e.printStackTrace(); 
  
        } 
  finally{ 
  
             
  try { 
  
                baos.close(); 
  
            }  
  catch (IOException e) { 
  
                 
  // 
   TODO Auto-generated catch block 
  
                e.printStackTrace(); 
  
            } 
  
             
  
        } 
  
         
  
    } 
 

}