RootCommand("su -c ‘screencap /mnt/sdcard/screenaaa.png‘ && adb pull /sdcard/screenaaa.png") ;

/**
	 * 应用程序运行命令获取 Root权限，设备必须已破解(获得ROOT权限)
	 * 
	 * @param command
	 *            命令：String apkRoot="chmod 777 "+getPackageCodePath();
	 *            RootCommand(apkRoot);
	 * @return 应用程序是/否获取Root权限
	 */
	private boolean RootCommand(String command) {
		Process process = null;
		DataOutputStream os = null;
		try {
			process = Runtime.getRuntime().exec("su");
			os = new DataOutputStream(process.getOutputStream());
			os.writeBytes(command + "\n");
			os.writeBytes("exit\n");
			os.flush();
			process.waitFor();
		} catch (Exception e) {
			Log.d("*** DEBUG ***", "ROOT REE" + e.getMessage());
			return false;
		} finally {
			try {
				if (os != null) {
					os.close();
				}
				process.destroy();
			} catch (Exception e) {
			}
		}
		Log.d("*** DEBUG ***", "Root SUC ");
		return true;
	}

android 后台截屏核心代码