Android蓝牙打印（转）

标签：打印机打印 bluetoothAdapter 蓝牙 Android 设备

把Android变为蓝牙打印设备

摘要

随着移动技术的快速发展，蓝牙打印设备在各行各业中得到广泛应用。本文将介绍如何将Android设备转化为蓝牙打印设备，以便实现无线打印功能。首先，我们将了解蓝牙打印机工作原理，然后介绍如何在Android平台上开发相关功能，并提供代码示例。

1. 蓝牙打印机工作原理

蓝牙打印机是一种通过无线蓝牙技术与其他设备进行通信的打印设备。它可以与手机、平板电脑等移动设备进行连接，并通过蓝牙协议传输打印数据。蓝牙打印机通常使用标准蓝牙协议，因此与支持蓝牙通信的设备兼容性较好。

蓝牙打印机通常可以接收文本、图片和其他格式的打印数据，并将其转化为可打印的格式。在打印之前，我们需要将要打印的内容通过蓝牙协议发送给打印机。蓝牙打印机将接收到的数据解析并打印出来，从而实现打印功能。

2. Android开发蓝牙打印功能

在Android平台上实现蓝牙打印功能需要以下步骤：

2.1 获取蓝牙适配器

首先，我们需要获取蓝牙适配器来管理Android设备上的蓝牙功能。可以使用BluetoothAdapter类来实现。

BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
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2.2 搜索蓝牙设备

接下来，我们需要搜索可用的蓝牙设备。可以使用startDiscovery()方法来启动蓝牙设备的搜索。

bluetoothAdapter.startDiscovery();
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2.3 连接蓝牙设备

搜索到可用的蓝牙设备后，我们可以使用BluetoothDevice类来获取设备实例，并通过createRfcommSocketToServiceRecord()方法来创建蓝牙连接。

BluetoothSocket socket = device.createRfcommSocketToServiceRecord(MY_UUID);
socket.connect();
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2.4 发送打印数据

连接成功后，我们可以通过OutputStream对象向蓝牙设备发送打印数据。

OutputStream outputStream = socket.getOutputStream();
outputStream.write(printData.getBytes());
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2.5 断开连接

打印完成后，我们需要断开与蓝牙设备的连接，可以使用close()方法来关闭蓝牙连接。

socket.close();
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3. 示例代码

下面是一个简单的示例代码，实现了将文本内容发送到蓝牙打印机并打印出来的功能。

public class MainActivity extends AppCompatActivity {
<span class="token keyword">private</span> <span class="token class-name">BluetoothAdapter</span> bluetoothAdapter<span class="token punctuation">;</span>
<span class="token keyword">private</span> <span class="token class-name">BluetoothDevice</span> bluetoothDevice<span class="token punctuation">;</span>
<span class="token keyword">private</span> <span class="token class-name">BluetoothSocket</span> bluetoothSocket<span class="token punctuation">;</span>

<span class="token annotation punctuation">@Override</span>
<span class="token keyword">protected</span> <span class="token keyword">void</span> <span class="token function">onCreate</span><span class="token punctuation">(</span><span class="token class-name">Bundle</span> savedInstanceState<span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token keyword">super</span><span class="token punctuation">.</span><span class="token function">onCreate</span><span class="token punctuation">(</span>savedInstanceState<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token function">setContentView</span><span class="token punctuation">(</span><span class="token class-name">R</span><span class="token punctuation">.</span>layout<span class="token punctuation">.</span>activity_main<span class="token punctuation">)</span><span class="token punctuation">;</span>

    bluetoothAdapter <span class="token operator">=</span> <span class="token class-name">BluetoothAdapter</span><span class="token punctuation">.</span><span class="token function">getDefaultAdapter</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token keyword">if</span> <span class="token punctuation">(</span>bluetoothAdapter <span class="token operator">==</span> <span class="token keyword">null</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
        <span class="token comment">// 设备不支持蓝牙功能</span>
        <span class="token keyword">return</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>

    <span class="token keyword">if</span> <span class="token punctuation">(</span><span class="token operator">!</span>bluetoothAdapter<span class="token punctuation">.</span><span class="token function">isEnabled</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
        <span class="token comment">// 蓝牙功能未开启，可以通过`startActivityForResult`方法来启动蓝牙功能</span>
        <span class="token class-name">Intent</span> enableBluetoothIntent <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Intent</span><span class="token punctuation">(</span><span class="token class-name">BluetoothAdapter</span><span class="token punctuation">.</span><span class="token constant">ACTION_REQUEST_ENABLE</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token function">startActivityForResult</span><span class="token punctuation">(</span>enableBluetoothIntent<span class="token punctuation">,</span> <span class="token constant">REQUEST_ENABLE_BT</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token punctuation">{</span>
        <span class="token function">searchBluetoothDevice</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>
<span class="token punctuation">}</span>

<span class="token keyword">private</span> <span class="token keyword">void</span> <span class="token function">searchBluetoothDevice</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token class-name">IntentFilter</span> filter <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">IntentFilter</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    filter<span class="token punctuation">.</span><span class="token function">addAction</span><span class="token punctuation">(</span><span class="token class-name">BluetoothDevice</span><span class="token punctuation">.</span><span class="token constant">ACTION_FOUND</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token function">registerReceiver</span><span class="token punctuation">(</span>bluetoothReceiver<span class="token punctuation">,</span> filter<span class="token punctuation">)</span><span class="token punctuation">;</span>

    bluetoothAdapter<span class="token punctuation">.</span><span class="token function">startDiscovery</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">private</span> <span class="token class-name">BroadcastReceiver</span> bluetoothReceiver <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">BroadcastReceiver</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">onReceive</span><span class="token punctuation">(</span><span class="token class-name">Context</span> context<span class="token punctuation">,</span> <span class="token class-name">Intent</span> intent<span class="token punctuation">)</span> <span class="token punctuation">{</span>
        <span class="token class-name">String</span> action <span class="token operator">=</span> intent<span class="token punctuation">.</span><span class="token function">getAction</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

        <span class="token keyword">if</span> <span class="token punctuation">(</span><span class="token class-name">BluetoothDevice</span><span class="token punctuation">.</span><span class="token constant">ACTION_FOUND</span><span class="token punctuation">.</span><span class="token function">equals</span><span class="token punctuation">(</span>action<span class="token punctuation">)</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
            <span class="token class-name">BluetoothDevice</span> device <span class="token operator">=</span> intent<span class="token punctuation">.</span><span class="token function">getParcelableExtra</span><span class="token punctuation">(</span><span class="token class-name">BluetoothDevice</span><span class="token punctuation">.</span><span class="token constant">EXTRA_DEVICE</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
            <span class="token keyword">if</span> <span class="token punctuation">(</span>device <span class="token operator">!=</span> <span class="token keyword">null</span> <span class="token operator">&amp;&amp;</span> device<span class="token punctuation">.</span><span class="token function">getName</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">equals</span><span class="token punctuation">(</span><span class="token string">"Printer"</span><span class="token punctuation">)</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
                bluetoothDevice <span class="token operator">=</span> device<span class="token punctuation">;</span>
                connectBluetoothDevice</code><ul class="pre-numbering"><li>1.</li><li>2.</li><li>3.</li><li>4.</li><li>5.</li><li>6.</li><li>7.</li><li>8.</li><li>9.</li><li>10.</li><li>11.</li><li>12.</li><li>13.</li><li>14.</li><li>15.</li><li>16.</li><li>17.</li><li>18.</li><li>19.</li><li>20.</li><li>21.</li><li>22.</li><li>23.</li><li>24.</li><li>25.</li><li>26.</li><li>27.</li><li>28.</li><li>29.</li><li>30.</li><li>31.</li><li>32.</li><li>33.</li><li>34.</li><li>35.</li><li>36.</li><li>37.</li><li>38.</li><li>39.</li><li>40.</li><li>41.</li><li>42.</li></ul></pre></div><div class="toolbar"></div></div>

标签：打印机,打印,bluetoothAdapter,蓝牙,Android,设备
From： https://www.cnblogs.com/lrzy/p/18131502

摘要