andriod+nfc

文章译自：Advanced NFC

本文档介绍了高级NFC，如与各种标签技术协作，NFC标签写入和前台调度，它允许应用程序在前台处理的intent，即使当其他应用程序过滤器相同的。

标签技术支持工作
当NFC标签和Android工作时，使用读取和写入数据的的主要格式是NDEF标签。当设备扫描标签NDEF数据，Android提供了解析NdefMessage消息和其他可能的支持。当扫描标签不包含NDEF数据或NDEF数据不能被映射到一个MIME类型或UR时，在这些情况下，你需要打开tag并直接与其信息交换和使用自己的协议读写数据（在原始字节）。Android为使用的android.nfc.tech包情况提供了通用的支持，android.nfc.tech包如表1中所描述的
。您可以使用的getTechList（）方法来确定标签的技术支持，并建立 与之一由android.nfc.tech类相应TagTechnology对象。

Table 1. Supported tag technologies

Class

Description

TagTechnology

所有标签技术类必须实现的接口。

NfcA

提供NFC-A（ISO 14443-3A）的性能和I / O操作的访问。

NfcB

提供NFC-B (ISO 14443-3B)的性能和I / O操作的访问。

NfcF

提供 NFC-F (JIS 6319-4)的性能和I / O操作的访问。

NfcV

提供 NFC-V (ISO 15693)的性能和I / O操作的访问。

IsoDep

提供 ISO-DEP (ISO 14443-4)的性能和I / O操作的访问。

Ndef

提供NFC标签已被格式化为NDEF的数据和操作的访问。

NdefFormatable

提供可能被格式化为NDEF的 formattable的标签。

下面的tag技术并不强制android设备支持（即选择性的支持）。

Table 2. Optional supported tag technologies

Class

Description

MifareClassic

如果此Android设备支持MIFARE,提供访问的MIFARE Classic性能和I / O操作。

MifareUltralight

如果此Android设备支持MIFARE,提供访问的MIFARE 超轻性能和I / O操作。

Tag技术与ACTION_TECH_DISCOVERED intent间协作

当设备扫描含有NDEF数据的tag，但不能被映射到一个MIME或URI，标签调度系统试图启动一个携带ACTION_TECH_DISCOVERED intent的activity。 扫描tag不是NDEF数据格式时，ACTION_TECH_DISCOVERED也可使用。有这种东西，如果标签调度系统无法解析tag时，可以直接与tag上数据进行交互。tag技术工作时的基本步骤如下：
1、过滤指定要处理的标签技术的ACTION_TECH_DISCOVERED intent。在一般情况下，标签调度系统尝试启动一个ACTION_TECH_DISCOVERED的intent，当NDEF消息，不能被映射为MIME类型或URI，或者如果标签扫描不包含NDEF数据。如何确定欲了解更多信息，请参阅标签调度系统。
2、当你的应用程序接收的intent，取得标签对象：

<span class="typ" style="color: rgb(102, 0, 102);">Tag</span><span class="pln" style="color: rgb(0, 0, 0);"> tagFromIntent </span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="pln" style="color: rgb(0, 0, 0);"> intent</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">getParcelableExtra</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="typ" style="color: rgb(102, 0, 102);">NfcAdapter</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">EXTRA_TAG</span><span class="pun" style="color: rgb(102, 102, 0);">);</span>

3、获得实例的TagTechnology，通过调用android.nfc.tech包 的get方法。调用get方法前，通过调用getTechList（）可以列举tag支持的技术。例如，从tag中要获得一个实例MifareUltralight，可以如下做：

<span class="typ" style="color: rgb(102, 0, 102);">MifareUltralight</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="kwd" style="color: rgb(0, 0, 136);">get</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="pln" style="color: rgb(0, 0, 0);">intent</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">getParcelableExtra</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="typ" style="color: rgb(102, 0, 102);">NfcAdapter</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">EXTRA_TAG</span><span class="pun" style="color: rgb(102, 102, 0);">));</span>

Tags读写

NFC标签读写必须确保获得intent并打开tag间通信。为了读取和写入数据到标签，您必须定义自己的协议栈。请记住，当直接与tag交互时，你仍然可以读取写NDEF格式的数据。它依赖你怎么去构建。下面的例子显示了如何使用一个MIFARE超轻标签。

<span class="kwd" style="color: rgb(0, 0, 136);">package</span><span class="pln" style="color: rgb(0, 0, 0);"> com</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">example</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">android</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">nfc</span><span class="pun" style="color: rgb(102, 102, 0);">;</span><span class="pln" style="color: rgb(0, 0, 0);">

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    </span><span class="kwd" style="color: rgb(0, 0, 136);">private</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">static</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">final</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">String</span><span class="pln" style="color: rgb(0, 0, 0);"> TAG </span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">MifareUltralightTagTester</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="kwd" style="color: rgb(0, 0, 136);">class</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">getSimpleName</span><span class="pun" style="color: rgb(102, 102, 0);">();</span><span class="pln" style="color: rgb(0, 0, 0);">

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        </span><span class="typ" style="color: rgb(102, 0, 102);">MifareUltralight</span><span class="pln" style="color: rgb(0, 0, 0);"> ultralight </span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">MifareUltralight</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="kwd" style="color: rgb(0, 0, 136);">get</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="pln" style="color: rgb(0, 0, 0);">tag</span><span class="pun" style="color: rgb(102, 102, 0);">);</span><span class="pln" style="color: rgb(0, 0, 0);">
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            ultralight</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">connect</span><span class="pun" style="color: rgb(102, 102, 0);">();</span><span class="pln" style="color: rgb(0, 0, 0);">
            ultralight</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">writePage</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="lit" style="color: rgb(0, 102, 102);">4</span><span class="pun" style="color: rgb(102, 102, 0);">,</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="str" style="color: rgb(0, 136, 0);">"abcd"</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">getBytes</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="typ" style="color: rgb(102, 0, 102);">Charset</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">forName</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="str" style="color: rgb(0, 136, 0);">"US-ASCII"</span><span class="pun" style="color: rgb(102, 102, 0);">)));</span><span class="pln" style="color: rgb(0, 0, 0);">
            ultralight</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">writePage</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="lit" style="color: rgb(0, 102, 102);">5</span><span class="pun" style="color: rgb(102, 102, 0);">,</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="str" style="color: rgb(0, 136, 0);">"efgh"</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">getBytes</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="typ" style="color: rgb(102, 0, 102);">Charset</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">forName</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="str" style="color: rgb(0, 136, 0);">"US-ASCII"</span><span class="pun" style="color: rgb(102, 102, 0);">)));</span><span class="pln" style="color: rgb(0, 0, 0);">
            ultralight</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">writePage</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="lit" style="color: rgb(0, 102, 102);">6</span><span class="pun" style="color: rgb(102, 102, 0);">,</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="str" style="color: rgb(0, 136, 0);">"ijkl"</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">getBytes</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="typ" style="color: rgb(102, 0, 102);">Charset</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">forName</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="str" style="color: rgb(0, 136, 0);">"US-ASCII"</span><span class="pun" style="color: rgb(102, 102, 0);">)));</span><span class="pln" style="color: rgb(0, 0, 0);">
            ultralight</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">writePage</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="lit" style="color: rgb(0, 102, 102);">7</span><span class="pun" style="color: rgb(102, 102, 0);">,</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="str" style="color: rgb(0, 136, 0);">"mnop"</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">getBytes</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="typ" style="color: rgb(102, 0, 102);">Charset</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">forName</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="str" style="color: rgb(0, 136, 0);">"US-ASCII"</span><span class="pun" style="color: rgb(102, 102, 0);">)));</span><span class="pln" style="color: rgb(0, 0, 0);">
        </span><span class="pun" style="color: rgb(102, 102, 0);">}</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">catch</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="typ" style="color: rgb(102, 0, 102);">IOException</span><span class="pln" style="color: rgb(0, 0, 0);"> e</span><span class="pun" style="color: rgb(102, 102, 0);">)</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);">
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                ultralight</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">close</span><span class="pun" style="color: rgb(102, 102, 0);">();</span><span class="pln" style="color: rgb(0, 0, 0);">
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        </span><span class="typ" style="color: rgb(102, 0, 102);">MifareUltralight</span><span class="pln" style="color: rgb(0, 0, 0);"> mifare </span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">MifareUltralight</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="kwd" style="color: rgb(0, 0, 136);">get</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="pln" style="color: rgb(0, 0, 0);">tag</span><span class="pun" style="color: rgb(102, 102, 0);">);</span><span class="pln" style="color: rgb(0, 0, 0);">
        </span><span class="kwd" style="color: rgb(0, 0, 136);">try</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);">
            mifare</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">connect</span><span class="pun" style="color: rgb(102, 102, 0);">();</span><span class="pln" style="color: rgb(0, 0, 0);">
            </span><span class="kwd" style="color: rgb(0, 0, 136);">byte</span><span class="pun" style="color: rgb(102, 102, 0);">[]</span><span class="pln" style="color: rgb(0, 0, 0);"> payload </span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="pln" style="color: rgb(0, 0, 0);"> mifare</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">readPages</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="lit" style="color: rgb(0, 102, 102);">4</span><span class="pun" style="color: rgb(102, 102, 0);">);</span><span class="pln" style="color: rgb(0, 0, 0);">
            </span><span class="kwd" style="color: rgb(0, 0, 136);">return</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">new</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">String</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="pln" style="color: rgb(0, 0, 0);">payload</span><span class="pun" style="color: rgb(102, 102, 0);">,</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">Charset</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">forName</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="str" style="color: rgb(0, 136, 0);">"US-ASCII"</span><span class="pun" style="color: rgb(102, 102, 0);">));</span><span class="pln" style="color: rgb(0, 0, 0);">
        </span><span class="pun" style="color: rgb(102, 102, 0);">}</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">catch</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="typ" style="color: rgb(102, 0, 102);">IOException</span><span class="pln" style="color: rgb(0, 0, 0);"> e</span><span class="pun" style="color: rgb(102, 102, 0);">)</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);">
            </span><span class="typ" style="color: rgb(102, 0, 102);">Log</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">e</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="pln" style="color: rgb(0, 0, 0);">TAG</span><span class="pun" style="color: rgb(102, 102, 0);">,</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="str" style="color: rgb(0, 136, 0);">"IOException while writing MifareUltralight
            message..."</span><span class="pun" style="color: rgb(102, 102, 0);">,</span><span class="pln" style="color: rgb(0, 0, 0);"> e</span><span class="pun" style="color: rgb(102, 102, 0);">);</span><span class="pln" style="color: rgb(0, 0, 0);">
        </span><span class="pun" style="color: rgb(102, 102, 0);">}</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">finally</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);">
            </span><span class="kwd" style="color: rgb(0, 0, 136);">if</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="pln" style="color: rgb(0, 0, 0);">mifare </span><span class="pun" style="color: rgb(102, 102, 0);">!=</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">null</span><span class="pun" style="color: rgb(102, 102, 0);">)</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);">
               </span><span class="kwd" style="color: rgb(0, 0, 136);">try</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);">
                   mifare</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">close</span><span class="pun" style="color: rgb(102, 102, 0);">();</span><span class="pln" style="color: rgb(0, 0, 0);">
               </span><span class="pun" style="color: rgb(102, 102, 0);">}</span><span class="pln" style="color: rgb(0, 0, 0);">
               </span><span class="kwd" style="color: rgb(0, 0, 136);">catch</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="typ" style="color: rgb(102, 0, 102);">IOException</span><span class="pln" style="color: rgb(0, 0, 0);"> e</span><span class="pun" style="color: rgb(102, 102, 0);">)</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);">
                   </span><span class="typ" style="color: rgb(102, 0, 102);">Log</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">e</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="pln" style="color: rgb(0, 0, 0);">TAG</span><span class="pun" style="color: rgb(102, 102, 0);">,</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="str" style="color: rgb(0, 136, 0);">"Error closing tag..."</span><span class="pun" style="color: rgb(102, 102, 0);">,</span><span class="pln" style="color: rgb(0, 0, 0);"> e</span><span class="pun" style="color: rgb(102, 102, 0);">);</span><span class="pln" style="color: rgb(0, 0, 0);">
               </span><span class="pun" style="color: rgb(102, 102, 0);">}</span><span class="pln" style="color: rgb(0, 0, 0);">
            </span><span class="pun" style="color: rgb(102, 102, 0);">}</span><span class="pln" style="color: rgb(0, 0, 0);">
        </span><span class="pun" style="color: rgb(102, 102, 0);">}</span><span class="pln" style="color: rgb(0, 0, 0);">
        </span><span class="kwd" style="color: rgb(0, 0, 136);">return</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">null</span><span class="pun" style="color: rgb(102, 102, 0);">;</span><span class="pln" style="color: rgb(0, 0, 0);">
    </span><span class="pun" style="color: rgb(102, 102, 0);">}</span><span class="pln" style="color: rgb(0, 0, 0);">
</span><span class="pun" style="color: rgb(102, 102, 0);">}</span>

前台调度系统的使用 前台调度系统允许activity截取intent并声明自己比其他处理相同intent的activity的优先级要高。使用这个系统可以为android系统构建一些数据结构，数据结构能够为应用程序发送适当的意图。为了使前景调度系统：
1、在activity的onCreate()方法中添加如下code： a、创建一个PendingIntent对象，android系统可以填充在tag被扫描到的内容。

<span class="typ" style="color: rgb(102, 0, 102);">PendingIntent</span><span class="pln" style="color: rgb(0, 0, 0);"> pendingIntent </span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">PendingIntent</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">getActivity</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="pln" style="color: rgb(0, 0, 0);">
 </span><span class="kwd" style="color: rgb(0, 0, 136);">this</span><span class="pun" style="color: rgb(102, 102, 0);">,</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="lit" style="color: rgb(0, 102, 102);">0</span><span class="pun" style="color: rgb(102, 102, 0);">,</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">new</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">Intent</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="kwd" style="color: rgb(0, 0, 136);">this</span><span class="pun" style="color: rgb(102, 102, 0);">,</span><span class="pln" style="color: rgb(0, 0, 0);"> getClass</span><span class="pun" style="color: rgb(102, 102, 0);">()).</span><span class="pln" style="color: rgb(0, 0, 0);">addFlags</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="typ" style="font-family: Arial, Helvetica, sans-serif; color: rgb(102, 0, 102);">Intent</span><span class="pun" style="font-family: Arial, Helvetica, sans-serif; color: rgb(102, 102, 0);">.</span><span class="pln" style="font-family: Arial, Helvetica, sans-serif; color: rgb(0, 0, 0);">FLAG_ACTIVITY_SINGLE_TOP</span><span class="pun" style="font-family: Arial, Helvetica, sans-serif; color: rgb(102, 102, 0);">),</span><span class="pln" style="font-family: Arial, Helvetica, sans-serif; color: rgb(0, 0, 0);"> </span><span class="lit" style="font-family: Arial, Helvetica, sans-serif; color: rgb(0, 102, 102);">0</span><span class="pun" style="font-family: Arial, Helvetica, sans-serif; color: rgb(102, 102, 0);">);</span>

b、声明intent过滤器来处理你想拦截的intent。前台调度系统检查过滤指定的intent，这个intent是扫描标签时收到的。如果匹配，那么你的应用程序处理的意图。如果它不匹配，前台调度系统回到intent调度系统的。指定一个空的数组intent过滤器和技术过滤器，指定要过滤所有的标签，回到TAG_DISCOVERED intent。下面的代码片段处理所有MIME类型NDEF_DISCOVERED。您应该只处理那些你需要的。

<span class="typ" style="color: rgb(102, 0, 102);">IntentFilter</span><span class="pln" style="color: rgb(0, 0, 0);"> ndef </span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">new</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">IntentFilter</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="typ" style="color: rgb(102, 0, 102);">NfcAdapter</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">ACTION_NDEF_DISCOVERED</span><span class="pun" style="color: rgb(102, 102, 0);">);</span><span class="pln" style="color: rgb(0, 0, 0);">
    </span><span class="kwd" style="color: rgb(0, 0, 136);">try</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);">
        ndef</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">addDataType</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="str" style="color: rgb(0, 136, 0);">"*/*"</span><span class="pun" style="color: rgb(102, 102, 0);">);</span><span class="com" style="color: rgb(136, 0, 0);">/* Handles all MIME based dispatches.
                             You should specify only the ones that you need. */</span><span class="pln" style="color: rgb(0, 0, 0);">
    </span><span class="pun" style="color: rgb(102, 102, 0);">}</span><span class="pln" style="color: rgb(0, 0, 0);">
    </span><span class="kwd" style="color: rgb(0, 0, 136);">catch</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="typ" style="color: rgb(102, 0, 102);">MalformedMimeTypeException</span><span class="pln" style="color: rgb(0, 0, 0);"> e</span><span class="pun" style="color: rgb(102, 102, 0);">)</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);">
        </span><span class="kwd" style="color: rgb(0, 0, 136);">throw</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">new</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">RuntimeException</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="str" style="color: rgb(0, 136, 0);">"fail"</span><span class="pun" style="color: rgb(102, 102, 0);">,</span><span class="pln" style="color: rgb(0, 0, 0);"> e</span><span class="pun" style="color: rgb(102, 102, 0);">);</span><span class="pln" style="color: rgb(0, 0, 0);">
    </span><span class="pun" style="color: rgb(102, 102, 0);">}</span><span class="pln" style="color: rgb(0, 0, 0);">
   intentFiltersArray </span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">new</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">IntentFilter</span><span class="pun" style="color: rgb(102, 102, 0);">[]</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);">ndef</span><span class="pun" style="color: rgb(102, 102, 0);">,</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">};</span>

c、设置您的应用程序要处理tag技术的数组。调用 Object.class.getName（）方法来获取支持的所以技术。

<span class="pln" style="color: rgb(0, 0, 0);">techListsArray </span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">new</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">String</span><span class="pun" style="color: rgb(102, 102, 0);">[][]</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">new</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">String</span><span class="pun" style="color: rgb(102, 102, 0);">[]</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="typ" style="color: rgb(102, 0, 102);">NfcF</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="kwd" style="color: rgb(0, 0, 136);">class</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">getName</span><span class="pun" style="color: rgb(102, 102, 0);">()</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">}</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">};</span>

2、重写以下activity生命周期回调函数，当activity失去（onPause()）和恢复（onResume()）焦点时，添加逻辑启用和禁用前台调度。enableForegroundDispatch（）必须主线程调用，并只有当activity在前台（调用onResume()保证这一点）。您还需要实现onNewIntent回调函数来处理扫描NFC标签的数据。

<span class="kwd" style="color: rgb(0, 0, 136);">public</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">void</span><span class="pln" style="color: rgb(0, 0, 0);"> onPause</span><span class="pun" style="color: rgb(102, 102, 0);">()</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);">
    </span><span class="kwd" style="color: rgb(0, 0, 136);">super</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">onPause</span><span class="pun" style="color: rgb(102, 102, 0);">();</span><span class="pln" style="color: rgb(0, 0, 0);">
    mAdapter</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">disableForegroundDispatch</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="kwd" style="color: rgb(0, 0, 136);">this</span><span class="pun" style="color: rgb(102, 102, 0);">);</span><span class="pln" style="color: rgb(0, 0, 0);">
</span><span class="pun" style="color: rgb(102, 102, 0);">}</span><span class="pln" style="color: rgb(0, 0, 0);">

</span><span class="kwd" style="color: rgb(0, 0, 136);">public</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">void</span><span class="pln" style="color: rgb(0, 0, 0);"> onResume</span><span class="pun" style="color: rgb(102, 102, 0);">()</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);">
    </span><span class="kwd" style="color: rgb(0, 0, 136);">super</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">onResume</span><span class="pun" style="color: rgb(102, 102, 0);">();</span><span class="pln" style="color: rgb(0, 0, 0);">
mAdapter</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">enableForegroundDispatch</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="kwd" style="color: rgb(0, 0, 136);">this</span><span class="pun" style="color: rgb(102, 102, 0);">,</span><span class="pln" style="color: rgb(0, 0, 0);">pendingIntent</span><span class="pun" style="color: rgb(102, 102, 0);">,</span><span class="pln" style="color: rgb(0, 0, 0);">intentFiltersArray</span><span class="pun" style="color: rgb(102, 102, 0);">,</span><span class="pln" style="color: rgb(0, 0, 0);">techListsArray</span><span class="pun" style="color: rgb(102, 102, 0);">);</span><span class="pln" style="color: rgb(0, 0, 0);">
</span><span class="pun" style="color: rgb(102, 102, 0);">}</span><span class="pln" style="color: rgb(0, 0, 0);">

</span><span class="kwd" style="color: rgb(0, 0, 136);">public</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="kwd" style="color: rgb(0, 0, 136);">void</span><span class="pln" style="color: rgb(0, 0, 0);"> onNewIntent</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="typ" style="color: rgb(102, 0, 102);">Intent</span><span class="pln" style="color: rgb(0, 0, 0);"> intent</span><span class="pun" style="color: rgb(102, 102, 0);">)</span><span class="pln" style="color: rgb(0, 0, 0);"> </span><span class="pun" style="color: rgb(102, 102, 0);">{</span><span class="pln" style="color: rgb(0, 0, 0);">
    </span><span class="typ" style="color: rgb(102, 0, 102);">Tag</span><span class="pln" style="color: rgb(0, 0, 0);"> tagFromIntent </span><span class="pun" style="color: rgb(102, 102, 0);">=</span><span class="pln" style="color: rgb(0, 0, 0);"> intent</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">getParcelableExtra</span><span class="pun" style="color: rgb(102, 102, 0);">(</span><span class="typ" style="color: rgb(102, 0, 102);">NfcAdapter</span><span class="pun" style="color: rgb(102, 102, 0);">.</span><span class="pln" style="color: rgb(0, 0, 0);">EXTRA_TAG</span><span class="pun" style="color: rgb(102, 102, 0);">);</span><span class="pln" style="color: rgb(0, 0, 0);">
    </span><span class="com" style="color: rgb(136, 0, 0);">//do something with tagFromIntent</span><span class="pln" style="color: rgb(0, 0, 0);">
</span><span class="pun" style="color: rgb(102, 102, 0);">}</span>