android中保存Bitmap图片到指定文件夹中的方法

/** 保存方法 */
public void saveBitmap() {
Log.e(TAG, "保存图片");
File f = new File("/sdcard/namecard/", picName);
if (f.exists()) {
f.delete();
}
try {
FileOutputStream out = new FileOutputStream(f);
bm.compress(Bitmap.CompressFormat.PNG, 90, out);
out.flush();
out.close();
Log.i(TAG, "已经保存");
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission roid:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>