Android read an instance of a picture at a specified size _android

In Android development, we often encounter the Android read image size more than the screen display map (generally as long as a certain size of the preview can be shown), in the picture is particularly large or the picture appears very often to pay special attention to this problem, the following describes a specified size to read the image method.

Implementation principle: First get picture file image high and wide, if less than the specified ratio, then read directly; If the ratio is exceeded, compress the read by the specified proportions.

Attention points when capturing OutOfMemoryError: The return is null, do not immediately read from other places, including the R file, or you will still throw this exception, usually in the initialization of the default image cache, and then display the picture in the cache.

/** get the width and height of the image **/

public static int[] GETIMAGEWH (String path) {int[] wh = {-1,-1};
 if (path = = null) {return WH;
 File File = new file (path); if (file.exists () &&!file.isdirectory ()) {try {bitmapfactory.options Options = new Bitmapfactory.options ()
   ;
   Options.injustdecodebounds = true;
   InputStream is = new FileInputStream (path);
   Bitmapfactory.decodestream (IS, null, options);
   Wh[0] = options.outwidth;
  WH[1] = options.outheight;
  catch (Exception e) {LOG.W (TAG, "Getimagewh Exception.", e);
} return WH;
 public static Bitmap Createbitmapbyscale (String path, int scale) {BITMAP BM = null;
  try {//Get width high int[] wh = GETIMAGEWH (path);
  if (wh[0] = =-1 | | wh[1] = = 1) {return null;
  //Read picture bitmapfactory.options Options = new Bitmapfactory.options ();
  Options.insamplesize = Math.max (Wh[0]/scale, Wh[1]/scale);
  	InputStream is = new FileInputStream (path);
 BM = Bitmapfactory.decodestream (IS, null, options);
 	catch (Exception e) {LOG.W (TAG, "Createbitmapbyscale Exception.", e);
  catch (OutOfMemoryError e) {LOG.W (TAG, "Createbitmapbyscale outofmemoryerror.", e);
 Todo:out of memory deal.
return BM; }

The above is to solve the Android reading picture size display problem, the need for friends can refer to the next.