Android关于Bitmap的几个方法

private String ALBUM_PATH = Environment.getExternalStorageDirectory().getAbsolutePath() + "/";

private void saveFile(Bitmap bm) throws IOException {
File dirFile = new File(ALBUM_PATH);
if (!dirFile.exists()) {
dirFile.mkdir();
}
File myCaptureFile = new File(ALBUM_PATH + "bitmap.jpeg");
BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(myCaptureFile));
bm.compress(Bitmap.CompressFormat.JPEG, 80, bos);
bos.flush();
bos.close();
}

private Bitmap smallBitmap(Bitmap bitmap) {
Matrix matrix = new Matrix();
matrix.postScale(0.33f, 0.33f); // 长和宽放大缩小的比例
Bitmap resizeBmp = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
return resizeBmp;
}

private Bitmap convertViewToBitmap(View view) {
Bitmap bitmap = Bitmap.createBitmap(view.getWidth(), view.getHeight(), Bitmap.Config.ARGB_8888);
view.draw(new Canvas(bitmap));

return bitmap;
}