android note3

SDCard

　　往SDCard存文件，必须判断手机是否安装有SDCard，并且可以进行读写，访问SDCard必须在AndroidMainfest.xml中加入访问权限

<!--在SDCard中创建与删除文件权限-->

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

<!--往SDCard写数据权限-->

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

if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
            //可以读写
            File sdCardDir = Environment.getExternalStorageDirectory(); //获取SDCard目录
            //或者File sdCardDir = new File("mnt/sdcard");

            File saveFile = new File(sdCardDir, "test.txt");
            try {
                FileOutputStream outStream = new FileOutputStream(saveFile);
                outStream.write("test sdcard".getBytes());
                outStream.close();
            } catch (FileNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }