基于Titanium的NFC应用不被标签触发

Question

我对 Appcelerator Titanium 的 ti.nfc module 有疑问。

我添加了模块并遵循了本指南：

http://vizteck.com/test/blog/nfc-data-communication-android-using-titanium

我也关注了Appcelerator的官方文档。

index.js:

var nfc = require("ti.nfc");
var nfcAdapter;

// This creates an NFC adapter associated with the current activity. 
// Each activity should have only ONE NFC adapter.
nfcAdapter = nfc.createNfcAdapter({
     onNdefDiscovered: handleNDEFDiscovery,
     onTagDiscovered: handleTagDiscovery,
     onTechDiscovered: handleTechDiscovery
});


function handleNDEFDiscovery(data){
    // alert('NDEF DISCOVERED:: ' + data.messages[0].records[0].getPayload());
    // Our required payload fits in the first record of the first Ndef msg
    var payload = data.messages[0].records[0].getPayload();
    // First byte of payload is control byte
    // Bits 5 to 0 of the control bytes contain 
    // length of language code succeeding the control byte
    var langCodeLength = payload[0] & 0077;
    // Received NFC text data starts after textOffset bytes in payload
    var textOffset = langCodeLength + 1;
    // Payload contains byte array which needs to be converted to a string
    // nfc_text contains the exact text string sent by the sending NFC device
    var nfc_text = payload.toString().substring(textOffset);
    /* process nfc_text as required by application logic here */
}

function handleTagDiscovery(data){
    alert('TAG DISCOVERED:: ' + data.messages[0].records[0].getPayload());
}

function handleTechDiscovery(data){
    alert('TECH DISCOVERED:: ' + data.messages[0].records[0].getPayload());
}

    // Check for NFC support on device
    if (!nfcAdapter.isEnabled()) {
        alert('NFC is not enabled on this device!');
    }else{        
        // Tag scans are received by the current activity as new intents. We
        // need to pass scan intents to the nfc adapter for processing.
        var act = Ti.Android.currentActivity;
        act.addEventListener('newintent', function(e) {
            nfcAdapter.onNewIntent(e.intent);
        });

        // Since we want the app to only use NFC while active in the foreground
        // We disable and enable foreground dispatch on app pause and resume respectively
        act.addEventListener('resume', function(e) {
            nfcAdapter.enableForegroundDispatch(dispatchFilter);
        });
        act.addEventListener('pause', function(e) {
            nfcAdapter.disableForegroundDispatch();
        });

        // The foreground dispatch filter specifies the types of NFC 
        // messages the app wants to receive and handle. The only entry in our case
        // specifies type ‘text/plain’ since we want to send and receive plain text
        dispatchFilter = nfc.createNfcForegroundDispatchFilter({
            intentFilters: [
                { action: nfc.ACTION_NDEF_DISCOVERED, mimeType: 'text/plain' },
            ],
            techLists: [
                [ "android.nfc.tech.NfcF" ],
                [ "android.nfc.tech.Ndef" ],
                [ "android.nfc.tech.MifareClassic" ],
                [ "android.nfc.tech.NfcA" ]
            ]
        });
        // This enables foreground dispatch for the first time
        nfcAdapter.enableForegroundDispatch(dispatchFilter);
    }

Android tiapp.xml:

<android xmlns:android="http://schemas.android.com/apk/res/android">
    <manifest>
<uses-permission android:name="android.permission.NFC"/>
<uses-permission android:name="android.permission.CALL_PHONE"/>
<uses-sdk android:minSdkVersion="14" />
        <application>
            <activity
             android:label="TagViewer" android:theme="@style/Theme.Titanium"
             android:configChanges="keyboardHidden|orientation"
             android:launchMode="singleTask">
                <intent-filter>
                    <action android:name="android.intent.action.MAIN" />
                    <category android:name="android.intent.category.LAUNCHER" />
                </intent-filter>
                <intent-filter>
                    <action android:name="android.nfc.action.NDEF_DISCOVERED"/>
                    <category android:name="android.intent.category.DEFAULT"/>
                    <data android:mimeType="text/plain"/>
                </intent-filter>
                <intent-filter>
                    <action android:name="android.nfc.action.NDEF_DISCOVERED"/>
                    <category android:name="android.intent.category.DEFAULT"/>
                    <data android:scheme="http"/>
                </intent-filter>
            </activity>
        </application>
    </manifest>
</android>

当我启动应用程序时，nfcAdapter 已启用并且我看到了以下 4 个警报：

[INFO] :   ALERT: (KrollRuntimeThread) [322,322] org.appcelerator.titanium.proxy.ActivityProxy@1a252dad
[INFO] :   ALERT: (KrollRuntimeThread) [0,322] org.appcelerator.kroll.runtime.v8.V8Function@368d58e2
[INFO] :   ALERT: (KrollRuntimeThread) [0,322] org.appcelerator.kroll.runtime.v8.V8Function@2c0fe473
[INFO] :   ALERT: (KrollRuntimeThread) [1,323] org.appcelerator.kroll.runtime.v8.V8Function@3e517f30

每次我拿着标签（卡片靠在 phone 的背面时，我都会在 appcelerator 的控制台中看到类似这样的内容：

[INFO] :   Timeline: Timeline: Activity_idle id: android.os.BinderProxy@30a1f176 time:23801469
[INFO] :   Timeline: Timeline: Activity_idle id: android.os.BinderProxy@30a1f176 time:23802093
etc...

我使用了在 Play 商店中找到的另一个应用程序 (NFC Reader)。我的标签包含的数据是：标签 ID（十六进制）、标签 ID（十进制）、ID（反转）。我使用的标签具有以下特征：

标签类型：ISO 15693
技术：NfcV、NdefFormatable
序列号：a2:3b:6b:1e:50:01:04:e0

Output from NFC Reader 问题是什么？为什么它不能很好地解释 tag/card？我希望你能帮助我。

非常感谢 ;)

Answer 1

鉴于 NFC Reader 的输出，您的标签不包含 NDEF 消息（因为它显示 "NdefFormatable" 而不是 "Ndef" 标签技术）。但是，您注册了 NFC intent 过滤器（在清单中和用于前台调度）以仅对包含文本记录（或 MIME 类型 "text/plain"）或 "http://" 的 NFC 标签敏感URL（仅在清单中注册）：

<intent-filter>
    <action android:name="android.nfc.action.NDEF_DISCOVERED"/>
    <category android:name="android.intent.category.DEFAULT"/>
    <data android:mimeType="text/plain"/>
</intent-filter>
<intent-filter>
    <action android:name="android.nfc.action.NDEF_DISCOVERED"/>
    <category android:name="android.intent.category.DEFAULT"/>
    <data android:scheme="http"/>
</intent-filter>

nfc.createNfcForegroundDispatchFilter({
        intentFilters: [
            { action: nfc.ACTION_NDEF_DISCOVERED, mimeType: 'text/plain' },
        ],
        ...

因此，您的应用程序不会选取标签。

对此你能做什么？

您可以使用应用程序期望的数据类型对标签进行编程（因此，您将文本记录写入标签），或者更改应用程序的 Intent 过滤器以正确发现该标签类型。

对于前台派发，可以用这段代码实现：

dispatchFilter = nfc.createNfcForegroundDispatchFilter({
    intentFilters: [
        { action: nfc.ACTION_TECH_DISCOVERED },
    ],
    techLists: [
        [ "android.nfc.tech.NfcV" ]
    ]
});

然后您将在 onTechDiscovered 回调中收到标签发现事件：

function handleTechDiscovery(data) {
    // do something
}

然后您可以根据需要处理标签。例如。如果你想读取标签 UID/anti-collision 标识符，你可以从 data 参数中获取 NfcTag 对象：

    var tag = data.tag;

并通过查询getId()方法获取UID：

    alert('Tag ID: ' + tag.getId());

Answer 2

谢谢迈克尔！我用你的替换了我的 "dispatchFilter" 并修改了函数 "handleTechDiscovery" 将 "data.messages[0].records[0].getPayload()" 更改为 "data".

现在，当我在 phone 的背面拿着标签卡时，我在 appcelerator 的控制台中看到如下内容：

[INFO]：I/Nfc 模块：android.nfc.action.TECH_DISCOVERED 收到意图但没有消息

[信息]：启用 NFC

[信息]：发现技术:: [对象对象]

我该怎么做才能正确读取 [object Object]？

为什么 "android.nfc.action.TECH_DISCOVERED intent received with no messages" 如果 Tag/card 包含数据？

再次感谢您的回复。

基于Titanium的NFC应用不被标签触发

NFC app based on Titanium is not triggered by tag

javascript

android

nfc

intentfilter

appcelerator-titanium

对此你能做什么？