将一个Bitmap 的内容存到file中
//create a file to write bitmap data File f = File(context.getCacheDir(), filename); f.createNewFile(); //Convert bitmap to byte array Bitmap bitmap = your bitmap; ByteArrayOutputStream bos = new ByteArrayOutputStream(); bitmap.compress(CompressFormat.PNG, 0 /*ignored for PNG*/, bos); byte[] bitmapdata = bos.toByteArray(); //write the bytes in file FileOutputStream fos = new FileOutputStream(f); fos.write(bitmapdata);思路:将Bitmap的内容,输入到输出流中,然后从输出流中把数据输出到文件中