Android Beam:使用MIME类型记录启动应用程序

Question

我正在开发一个项目,我正在使用Android智能手机和PN532 USB芯片(elechouse),它具有点对点模式作为其功能之一.我试图将PN532模块的NDEF消息发送到智能手机,相反,它工作正常.

我想要的是,当PN532模块找到智能手机时,我的应用程序会自动启动.

我知道一个解决方案是使用MIME类型记录.

我的清单中有这个:

 <data android:mimeType="application/vnd.test.com.openapp"/>

在模块方面,我可以传输MIME,但我不知道这个MIME必须是什么形式.我试图传输字符串但没有任何反应.

那么如何在我的模块上创建MIME类型记录呢？有没有其他方式通过点对点通信启动我的应用程序？

Answer 1

首先,您必须实现对等协议栈:

+--------------------------------------+
|   NDEF (NFC Data Exchange Format)    |
+--------------------------------------+
| SNEP (Simple NDEF Exchange Protocol) |
+--------------------------------------+
| LLCP (Logical Link Control Protocol) |
+--------------------------------------+
|               NFCIP-1                |
+--------------------------------------+

您似乎已经启动并运行了,因为您指示您" 尝试将PNDE32模块中的NDEF消息发送到智能手机,反之亦然. "

因此,接下来您需要创建一个带有MIME类型记录(甚至更好的NFC论坛外部类型记录)的NDEF消息作为其第一条记录.为了使用Android的AAR(Android应用程序记录)设施NDEF消息绑定到只有您的应用程序(APP要么推出或者,如果没有安装,应用的Google Play商店页面被打开),你可以另外添加一个AAR到底您的NDEF消息.

仅包含MIME类型记录的NDEF消息:

+------+------+------+------+------+--------------------------+
| MB=1 | ME=1 | CF=0 | SR=1 | IL=0 | TNF=2 (MIME type record) |
+------+------+------+------+------+--------------------------+
| TYPE LENGTH=32 (0x20)                                       |
+-------------------------------------------------------------+
| PAYLOAD LENGTH=5 (0x05)                                     |
+-------------------------------------------------------------+
| TYPE="application/vnd.test.com.openapp"                     |
+-------------------------------------------------------------+
| PAYLOAD="Hello"                                             |
+-------------------------------------------------------------+

作为字节数组,这看起来像

{
    /* Header byte    */ 0xD2,
    /* TYPE LENGTH    */ 0x20,
    /* PAYLOAD LENGTH */ 0x05,
    /* TYPE           */ 0x61, 0x70, 0x70, 0x6C, 0x69, 0x63, 0x61, 0x74,
                         0x69, 0x6F, 0x6E, 0x2F, 0x76, 0x6E, 0x64, 0x2E,
                         0x74, 0x65, 0x73, 0x74, 0x2E, 0x63, 0x6F, 0x6D,
                         0x2E, 0x6F, 0x70, 0x65, 0x6E, 0x61, 0x70, 0x70,
    /* PAYLOAD        */ 0x48, 0x65, 0x6C, 0x6C, 0x6F
}

然后,您可以使用清单中的类似意图过滤器注册要启动的应用:

<intent-filter>
    <action android:name="android.nfc.action.NDEF_DISCOVERED" />
    <category android:name="android.intent.category.DEFAULT" />
    <data android:mimeType="application/vnd.test.com.openapp" />
</intent-filter>    

对于AAR变体,您可以将应用的AAR附加到该消息.例如,如果您的应用的包名称为"com.your.app.package":

+------+------+------+------+------+--------------------------+
| MB=1 | ME=0 | CF=0 | SR=1 | IL=0 | TNF=2 (MIME type record) |
+------+------+------+------+------+--------------------------+
| TYPE LENGTH=32 (0x20)                                       |
+-------------------------------------------------------------+
| PAYLOAD LENGTH=5 (0x05)                                     |
+-------------------------------------------------------------+
| TYPE="application/vnd.test.com.openapp"                     |
+-------------------------------------------------------------+
| PAYLOAD="Hello"                                             |
+-------------------------------------------------------------+
+------+------+------+------+------+--------------------------+
| MB=0 | ME=1 | CF=0 | SR=1 | IL=0 | TNF=4 (External type)    |
+------+------+------+------+------+--------------------------+
| TYPE LENGTH=15 (0x0F)                                       |
+-------------------------------------------------------------+
| PAYLOAD LENGTH=20 (0x14)                                    |
+-------------------------------------------------------------+
| TYPE="android.com:pkg"                                      |
+-------------------------------------------------------------+
| PAYLOAD="com.your.app.package"                              |
+-------------------------------------------------------------+

作为字节数组,这看起来像

{
    /* MIME type record */
    /* Header byte    */ 0x92,
    /* TYPE LENGTH    */ 0x20,
    /* PAYLOAD LENGTH */ 0x05,
    /* TYPE           */ 0x61, 0x70, 0x70, 0x6C, 0x69, 0x63, 0x61, 0x74,
                         0x69, 0x6F, 0x6E, 0x2F, 0x76, 0x6E, 0x64, 0x2E,
                         0x74, 0x65, 0x73, 0x74, 0x2E, 0x63, 0x6F, 0x6D,
                         0x2E, 0x6F, 0x70, 0x65, 0x6E, 0x61, 0x70, 0x70,
    /* PAYLOAD        */ 0x48, 0x65, 0x6C, 0x6C, 0x6F,
    /* Android Application Record */
    /* Header byte    */ 0x54,
    /* TYPE LENGTH    */ 0x0F,
    /* PAYLOAD LENGTH */ 0x14,
    /* TYPE           */ 0x61, 0x6E, 0x64, 0x72, 0x6F, 0x69, 0x64, 0x2E,
                         0x63, 0x6F, 0x6D, 0x3A, 0x70, 0x6B, 0x67
    /* PAYLOAD        */ 0x63, 0x6F, 0x6D, 0x2E, 0x79, 0x6F, 0x75, 0x72,
                         0x2E, 0x61, 0x70, 0x70, 0x2E, 0x70, 0x61, 0x63,
                         0x6B, 0x61, 0x67, 0x65
}