android:text="打印" />
<Button
android:id="@+id/command"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/send"
android:text="指令" />
至此，布局文件就搞定了，接下来就要编写java代码了。主要有一下这么几个类，一个一个来哈
**BluetoothActivity.java**
这个类的主要作用是初始化主界面，看代码
**\[java\]** [view plain]( ) [copy]( ) [print]( ) [?]( )
1. public class BluetoothActivity extends Activity {
2. private Context context = null;
4. public void onCreate(Bundle savedInstanceState) {
5. super.onCreate(savedInstanceState);
6. this.context = this;
7. setTitle("蓝牙打印");
8. setContentView(R.layout.bluetooth\_layout);
9. this.initListener();
10. }
12. private void initListener() {
13. ListView unbondDevices = (ListView) this
14. .findViewById(R.id.unbondDevices);
15. ListView bondDevices = (ListView) this.findViewById(R.id.bondDevices);
16. Button switchBT = (Button) this.findViewById(R.id.openBluetooth\_tb);
17. Button searchDevices = (Button) this.findViewById(R.id.searchDevices);
19. BluetoothAction bluetoothAction = new BluetoothAction(this.context,
20. unbondDevices, bondDevices, switchBT, searchDevices,
21. BluetoothActivity.this);
23. Button returnButton = (Button) this
24. .findViewById(R.id.return\_Bluetooth\_btn);
25. bluetoothAction.setSearchDevices(searchDevices);
26. bluetoothAction.initView();
28. switchBT.setOnClickListener(bluetoothAction);
29. searchDevices.setOnClickListener(bluetoothAction);
30. returnButton.setOnClickListener(bluetoothAction);
31. }
32. //屏蔽返回键的代码:
33. public boolean onKeyDown(int keyCode,KeyEvent event)
34. {
35. switch(keyCode)
36. {
37. case KeyEvent.KEYCODE\_BACK:return true;
38. }
39. return super.onKeyDown(keyCode, event);
40. }
41. }
public class BluetoothActivity extends Activity {
private Context context = null;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.context = this;
setTitle("蓝牙打印");
setContentView(R.layout.bluetooth_layout);
this.initListener();
}
private void initListener() {
ListView unbondDevices = (ListView) this
.findViewById(R.id.unbondDevices);
ListView bondDevices = (ListView) this.findViewById(R.id.bondDevices);
Button switchBT = (Button) this.findViewById(R.id.openBluetooth_tb);
Button searchDevices = (Button) this.findViewById(R.id.searchDevices);
BluetoothAction bluetoothAction = new BluetoothAction(this.context,
unbondDevices, bondDevices, switchBT, searchDevices,
BluetoothActivity.this);
Button returnButton = (Button) this
.findViewById(R.id.return_Bluetooth_btn);
bluetoothAction.setSearchDevices(searchDevices);
bluetoothAction.initView();
switchBT.setOnClickListener(bluetoothAction);
searchDevices.setOnClickListener(bluetoothAction);
returnButton.setOnClickListener(bluetoothAction);
}
//屏蔽返回键的代码:
public boolean onKeyDown(int keyCode,KeyEvent event)
{
switch(keyCode)
{
case KeyEvent.KEYCODE_BACK:return true;
}
return super.onKeyDown(keyCode, event);
}
}
**BluetoothAction.java**
这个类顾名思义，是处理bluetoothActivity中各种操作事件的action类，看代码
**\[java\]** [view plain]( ) [copy]( ) [print]( ) [?]( )
1. <span style="font-size: 14px;"\>public class BluetoothAction implements OnClickListener {
3. private Button switchBT = null;
4. private Button searchDevices = null;
5. private Activity activity = null;
7. private ListView unbondDevices = null;
8. private ListView bondDevices = null;
9. private Context context = null;
10. private BluetoothService bluetoothService = null;
12. public BluetoothAction(Context context, ListView unbondDevices,
13. ListView bondDevices, Button switchBT, Button searchDevices,
14. Activity activity) {
15. super();
16. this.context = context;
17. this.unbondDevices = unbondDevices;
18. this.bondDevices = bondDevices;
19. this.switchBT = switchBT;
20. this.searchDevices = searchDevices;
21. this.activity = activity;
22. this.bluetoothService = new BluetoothService(this.context,
23. this.unbondDevices, this.bondDevices, this.switchBT,
24. this.searchDevices);
25. }
27. public void setSwitchBT(Button switchBT) {
28. this.switchBT = switchBT;
29. }
31. public void setSearchDevices(Button searchDevices) {
32. this.searchDevices = searchDevices;
33. }
35. public void setUnbondDevices(ListView unbondDevices) {
36. this.unbondDevices = unbondDevices;
37. }
39. /\*\*
40. \* 初始化界面
41. \*/
42. public void initView() {
44. if (this.bluetoothService.isOpen()) {
45. System.out.println("蓝牙有开!");
46. switchBT.setText("关闭蓝牙");
47. }
48. if (!this.bluetoothService.isOpen()) {
49. System.out.println("蓝牙没开!");
50. this.searchDevices.setEnabled(false);
51. }
52. }
54. private void searchDevices() {
55. bluetoothService.searchDevices();
56. }
58. /\*\*
59. \* 各种按钮的监听
60. \*/
61. @Override
62. public void onClick(View v) {
63. if (v.getId() == R.id.searchDevices) {
64. this.searchDevices();
65. } else if (v.getId() == R.id.return\_Bluetooth\_btn) {
66. activity.finish();
67. } else if (v.getId() == R.id.openBluetooth\_tb) {
68. if (!this.bluetoothService.isOpen()) {
69. // 蓝牙关闭的情况
70. System.out.println("蓝牙关闭的情况");
71. this.bluetoothService.openBluetooth(activity);
72. } else {
73. // 蓝牙打开的情况
74. System.out.println("蓝牙打开的情况");
75. this.bluetoothService.closeBluetooth();
77. }
79. }
80. }
82. }</span>
public class BluetoothAction implements OnClickListener {
private Button switchBT = null;
private Button searchDevices = null;
private Activity activity = null;
private ListView unbondDevices = null;
private ListView bondDevices = null;
private Context context = null;
private BluetoothService bluetoothService = null;
public BluetoothAction(Context context, ListView unbondDevices,
ListView bondDevices, Button switchBT, Button searchDevices,
Activity activity) {
super();
this.context = context;
this.unbondDevices = unbondDevices;
this.bondDevices = bondDevices;
this.switchBT = switchBT;
this.searchDevices = searchDevices;
this.activity = activity;
this.bluetoothService = new BluetoothService(this.context,
this.unbondDevices, this.bondDevices, this.switchBT,
this.searchDevices);
}
public void setSwitchBT(Button switchBT) {
this.switchBT = switchBT;
}
public void setSearchDevices(Button searchDevices) {
this.searchDevices = searchDevices;
}
public void setUnbondDevices(ListView unbondDevices) {
this.unbondDevices = unbondDevices;
}
/**
* 初始化界面
*/
public void initView() {
if (this.bluetoothService.isOpen()) {
System.out.println("蓝牙有开!");
switchBT.setText("关闭蓝牙");
}
if (!this.bluetoothService.isOpen()) {
System.out.println("蓝牙没开!");
this.searchDevices.setEnabled(false);
}
}
private void searchDevices() {
bluetoothService.searchDevices();
}
/**
* 各种按钮的监听
*/
@Override
public void onClick(View v) {
if (v.getId() == R.id.searchDevices) {
this.searchDevices();
} else if (v.getId() == R.id.return_Bluetooth_btn) {
activity.finish();
} else if (v.getId() == R.id.openBluetooth_tb) {
if (!this.bluetoothService.isOpen()) {
// 蓝牙关闭的情况
System.out.println("蓝牙关闭的情况");
this.bluetoothService.openBluetooth(activity);
} else {
// 蓝牙打开的情况
System.out.println("蓝牙打开的情况");
this.bluetoothService.closeBluetooth();
}
}
}
}
这个类会把各种请求动作分门别类，交给**BluetoothService.java**来处理，看代码
**\[java\]** [view plain]( ) [copy]( ) [print]( ) [?]( )
1. public class BluetoothService {
2. private Context context = null;
3. private BluetoothAdapter bluetoothAdapter = BluetoothAdapter
4. .getDefaultAdapter();
5. private ArrayList<BluetoothDevice> unbondDevices = null; // 用于存放未配对蓝牙设备
6. private ArrayList<BluetoothDevice> bondDevices = null;// 用于存放已配对蓝牙设备
7. private Button switchBT = null;
8. private Button searchDevices = null;
9. private ListView unbondDevicesListView = null;
10. private ListView bondDevicesListView = null;
12. /\*\*
13. \* 添加已绑定蓝牙设备到ListView
14. \*/
15. private void addBondDevicesToListView() {
16. ArrayList<HashMap<String, Object>> data = new ArrayList<HashMap<String, Object>>();
17. int count = this.bondDevices.size();
18. System.out.println("已绑定设备数量：" + count);
19. for (int i = 0; i < count; i++) {
20. HashMap<String, Object> map = new HashMap<String, Object>();
21. map.put("deviceName", this.bondDevices.get(i).getName());
22. data.add(map);// 把item项的数据加到data中
23. }
24. String\[\] from = { "deviceName" };
25. int\[\] to = { R.id.device\_name };
26. SimpleAdapter simpleAdapter = new SimpleAdapter(this.context, data,
27. R.layout.bonddevice\_item, from, to);
28. // 把适配器装载到listView中
29. this.bondDevicesListView.setAdapter(simpleAdapter);
31. this.bondDevicesListView
32. .setOnItemClickListener(new OnItemClickListener() {
34. @Override
35. public void onItemClick(AdapterView<?> arg0, View arg1,
36. int arg2, long arg3) {
37. BluetoothDevice device = bondDevices.get(arg2);
38. Intent intent = new Intent();
39. intent.setClassName(context,
40. "com.lifeng.jdxt.view.PrintDataActivity");
41. intent.putExtra("deviceAddress", device.getAddress());
42. context.startActivity(intent);
43. }
44. });
46. }
48. /\*\*
49. \* 添加未绑定蓝牙设备到ListView
50. \*/
51. private void addUnbondDevicesToListView() {
52. ArrayList<HashMap<String, Object>> data = new ArrayList<HashMap<String, Object>>();
53. int count = this.unbondDevices.size();
54. System.out.println("未绑定设备数量：" + count);
55. for (int i = 0; i < count; i++) {
56. HashMap<String, Object> map = new HashMap<String, Object>();
57. map.put("deviceName", this.unbondDevices.get(i).getName());
58. data.add(map);// 把item项的数据加到data中
59. }
60. String\[\] from = { "deviceName" };
61. int\[\] to = { R.id.device\_name };
62. SimpleAdapter simpleAdapter = new SimpleAdapter(this.context, data,
63. R.layout.unbonddevice\_item, from, to);
65. // 把适配器装载到listView中
66. this.unbondDevicesListView.setAdapter(simpleAdapter);
68. // 为每个item绑定监听，用于设备间的配对
69. this.unbondDevicesListView
70. .setOnItemClickListener(new OnItemClickListener() {
72. @Override
73. public void onItemClick(AdapterView<?> arg0, View arg1,
74. int arg2, long arg3) {
75. try {
76. Method createBondMethod = BluetoothDevice.class
77. .getMethod("createBond");
78. createBondMethod
79. .invoke(unbondDevices.get(arg2));
80. // 将绑定好的设备添加的已绑定list集合
81. bondDevices.add(unbondDevices.get(arg2));
82. // 将绑定好的设备从未绑定list集合中移除
83. unbondDevices.remove(arg2);
84. addBondDevicesToListView();
85. addUnbondDevicesToListView();
86. } catch (Exception e) {
87. Toast.makeText(context, "配对失败！", Toast.LENGTH\_SHORT)
88. .show();
89. }
91. }
92. });
93. }
95. public BluetoothService(Context context, ListView unbondDevicesListView,
96. ListView bondDevicesListView, Button switchBT, Button searchDevices) {
97. this.context = context;
98. this.unbondDevicesListView = unbondDevicesListView;
99. this.bondDevicesListView = bondDevicesListView;
100. // this.bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
101. this.unbondDevices = new ArrayList<BluetoothDevice>();
102. this.bondDevices = new ArrayList<BluetoothDevice>();
103. this.switchBT = switchBT;
104. this.searchDevices = searchDevices;
105. this.initIntentFilter();
107. }
109. private void initIntentFilter() {
110. // 设置广播信息过滤
111. IntentFilter intentFilter = new IntentFilter();
112. intentFilter.addAction(BluetoothDevice.ACTION\_FOUND);
113. intentFilter.addAction(BluetoothAdapter.ACTION\_DISCOVERY\_STARTED);
114. intentFilter.addAction(BluetoothAdapter.ACTION\_DISCOVERY\_FINISHED);
115. intentFilter.addAction(BluetoothAdapter.ACTION\_STATE\_CHANGED);
116. // 注册广播接收器，接收并处理搜索结果
117. context.registerReceiver(receiver, intentFilter);
119. }
121. /\*\*
122. \* 打开蓝牙
123. \*/
124. public void openBluetooth(Activity activity) {
125. Intent enableBtIntent = new Intent(
126. BluetoothAdapter.ACTION\_REQUEST\_ENABLE);
127. activity.startActivityForResult(enableBtIntent, 1);
129. }
131. /\*\*
132. \* 关闭蓝牙
133. \*/
134. public void closeBluetooth() {
135. this.bluetoothAdapter.disable();
136. }
138. /\*\*
139. \* 判断蓝牙是否打开
140. \*
141. \* @return boolean
142. \*/
143. public boolean isOpen() {
144. return this.bluetoothAdapter.isEnabled();
146. }
148. /\*\*
149. \* 搜索蓝牙设备
150. \*/
151. public void searchDevices() {
152. this.bondDevices.clear();
153. this.unbondDevices.clear();
155. // 寻找蓝牙设备，android会将查找到的设备以广播形式发出去
156. this.bluetoothAdapter.startDiscovery();
157. }
159. /\*\*
160. \* 添加未绑定蓝牙设备到list集合
161. \*
162. \* @param device
163. \*/
164. public void addUnbondDevices(BluetoothDevice device) {
165. System.out.println("未绑定设备名称：" + device.getName());
166. if (!this.unbondDevices.contains(device)) {
167. this.unbondDevices.add(device);
168. }
169. }
171. /\*\*
172. \* 添加已绑定蓝牙设备到list集合
173. \*
174. \* @param device
175. \*/
176. public void addBandDevices(BluetoothDevice device) {
177. System.out.println("已绑定设备名称：" + device.getName());
178. if (!this.bondDevices.contains(device)) {
179. this.bondDevices.add(device);
180. }
181. }
183. /\*\*
184. \* 蓝牙广播接收器
185. \*/
186. private BroadcastReceiver receiver = new BroadcastReceiver() {
188. ProgressDialog progressDialog = null;
190. @Override
191. public void onReceive(Context context, Intent intent) {
192. String action = intent.getAction();
193. if (BluetoothDevice.ACTION\_FOUND.equals(action)) {
194. BluetoothDevice device = intent
195. .getParcelableExtra(BluetoothDevice.EXTRA\_DEVICE);
196. if (device.getBondState() == BluetoothDevice.BOND\_BONDED) {
197. addBandDevices(device);
198. } else {
199. addUnbondDevices(device);
200. }
201. } else if (BluetoothAdapter.ACTION\_DISCOVERY\_STARTED.equals(action)) {
202. progressDialog = ProgressDialog.show(context, "请稍等...",
203. "搜索蓝牙设备中...", true);
205. } else if (BluetoothAdapter.ACTION\_DISCOVERY\_FINISHED
206. .equals(action)) {
207. System.out.println("设备搜索完毕");
208. progressDialog.dismiss();
210. addUnbondDevicesToListView();
211. addBondDevicesToListView();
212. // bluetoothAdapter.cancelDiscovery();
213. }
214. if (BluetoothAdapter.ACTION\_STATE\_CHANGED.equals(action)) {
215. if (bluetoothAdapter.getState() == BluetoothAdapter.STATE\_ON) {
216. System.out.println("--------打开蓝牙-----------");
217. switchBT.setText("关闭蓝牙");
218. searchDevices.setEnabled(true);
219. bondDevicesListView.setEnabled(true);
220. unbondDevicesListView.setEnabled(true);
221. } else if (bluetoothAdapter.getState() == BluetoothAdapter.STATE\_OFF) {
222. System.out.println("--------关闭蓝牙-----------");
223. switchBT.setText("打开蓝牙");
224. searchDevices.setEnabled(false);
225. bondDevicesListView.setEnabled(false);
226. unbondDevicesListView.setEnabled(false);
227. }
228. }
230. }
232. };
234. }
public class BluetoothService {
private Context context = null;
private BluetoothAdapter bluetoothAdapter = BluetoothAdapter
.getDefaultAdapter();
private ArrayList<BluetoothDevice> unbondDevices = null; // 用于存放未配对蓝牙设备
private ArrayList<BluetoothDevice> bondDevices = null;// 用于存放已配对蓝牙设备
private Button switchBT = null;
private Button searchDevices = null;
private ListView unbondDevicesListView = null;
private ListView bondDevicesListView = null;
/**
* 添加已绑定蓝牙设备到ListView
*/
private void addBondDevicesToListView() {
ArrayList<HashMap<String, Object>> data = new ArrayList<HashMap<String, Object>>();
int count = this.bondDevices.size();
System.out.println("已绑定设备数量：" + count);
for (int i = 0; i < count; i++) {
HashMap<String, Object> map = new HashMap<String, Object>();
map.put("deviceName", this.bondDevices.get(i).getName());
data.add(map);// 把item项的数据加到data中
}
String[] from = { "deviceName" };
int[] to = { R.id.device_name };
SimpleAdapter simpleAdapter = new SimpleAdapter(this.context, data,
R.layout.bonddevice_item, from, to);
// 把适配器装载到listView中
this.bondDevicesListView.setAdapter(simpleAdapter);
this.bondDevicesListView
.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1,
int arg2, long arg3) {
BluetoothDevice device = bondDevices.get(arg2);
Intent intent = new Intent();
intent.setClassName(context,
"com.lifeng.jdxt.view.PrintDataActivity");
intent.putExtra("deviceAddress", device.getAddress());
context.startActivity(intent);
}
});
}
/**
* 添加未绑定蓝牙设备到ListView
*/
private void addUnbondDevicesToListView() {
ArrayList<HashMap<String, Object>> data = new ArrayList<HashMap<String, Object>>();
int count = this.unbondDevices.size();
System.out.println("未绑定设备数量：" + count);
for (int i = 0; i < count; i++) {
HashMap<String, Object> map = new HashMap<String, Object>();
map.put("deviceName", this.unbondDevices.get(i).getName());
data.add(map);// 把item项的数据加到data中
}
String[] from = { "deviceName" };
int[] to = { R.id.device_name };
SimpleAdapter simpleAdapter = new SimpleAdapter(this.context, data,
R.layout.unbonddevice_item, from, to);
// 把适配器装载到listView中
this.unbondDevicesListView.setAdapter(simpleAdapter);
// 为每个item绑定监听，用于设备间的配对
this.unbondDevicesListView
.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1,
int arg2, long arg3) {
try {
Method createBondMethod = BluetoothDevice.class
.getMethod("createBond");
createBondMethod
.invoke(unbondDevices.get(arg2));
// 将绑定好的设备添加的已绑定list集合
bondDevices.add(unbondDevices.get(arg2));
// 将绑定好的设备从未绑定list集合中移除
unbondDevices.remove(arg2);
addBondDevicesToListView();
addUnbondDevicesToListView();
} catch (Exception e) {
Toast.makeText(context, "配对失败！", Toast.LENGTH_SHORT)
.show();
}
}
});
}
public BluetoothService(Context context, ListView unbondDevicesListView,
ListView bondDevicesListView, Button switchBT, Button searchDevices) {
this.context = context;
this.unbondDevicesListView = unbondDevicesListView;
this.bondDevicesListView = bondDevicesListView;
// this.bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
this.unbondDevices = new ArrayList<BluetoothDevice>();
this.bondDevices = new ArrayList<BluetoothDevice>();
this.switchBT = switchBT;
this.searchDevices = searchDevices;
this.initIntentFilter();
}
private void initIntentFilter() {
// 设置广播信息过滤
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(BluetoothDevice.ACTION_FOUND);
intentFilter.addAction(BluetoothAdapter.ACTION_DISCOVERY_STARTED);
intentFilter.addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
intentFilter.addAction(BluetoothAdapter.ACTION_STATE_CHANGED);
// 注册广播接收器，接收并处理搜索结果
context.registerReceiver(receiver, intentFilter);
}
/**
* 打开蓝牙
*/
public void openBluetooth(Activity activity) {
Intent enableBtIntent = new Intent(
BluetoothAdapter.ACTION_REQUEST_ENABLE);
activity.startActivityForResult(enableBtIntent, 1);
}
/**
* 关闭蓝牙
*/
public void closeBluetooth() {
this.bluetoothAdapter.disable();
}
/**
* 判断蓝牙是否打开
*
* @return boolean
*/
public boolean isOpen() {
return this.bluetoothAdapter.isEnabled();
}
/**
* 搜索蓝牙设备
*/
public void searchDevices() {
this.bondDevices.clear();
this.unbondDevices.clear();
// 寻找蓝牙设备，android会将查找到的设备以广播形式发出去
this.bluetoothAdapter.startDiscovery();
}
/**
* 添加未绑定蓝牙设备到list集合
*
* @param device
*/
public void addUnbondDevices(BluetoothDevice device) {
System.out.println("未绑定设备名称：" + device.getName());
if (!this.unbondDevices.contains(device)) {
this.unbondDevices.add(device);
}
}
/**
* 添加已绑定蓝牙设备到list集合
*
* @param device
*/
public void addBandDevices(BluetoothDevice device) {
System.out.println("已绑定设备名称：" + device.getName());
if (!this.bondDevices.contains(device)) {
this.bondDevices.add(device);
}
}
/**
* 蓝牙广播接收器
*/
private BroadcastReceiver receiver = new BroadcastReceiver() {
ProgressDialog progressDialog = null;
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
BluetoothDevice device = intent
.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
if (device.getBondState() == BluetoothDevice.BOND_BONDED) {
addBandDevices(device);
} else {
addUnbondDevices(device);
}
} else if (BluetoothAdapter.ACTION_DISCOVERY_STARTED.equals(action)) {
progressDialog = ProgressDialog.show(context, "请稍等...",
"搜索蓝牙设备中...", true);
} else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED
.equals(action)) {
System.out.println("设备搜索完毕");
progressDialog.dismiss();
addUnbondDevicesToListView();
addBondDevicesToListView();
// bluetoothAdapter.cancelDiscovery();
}
if (BluetoothAdapter.ACTION_STATE_CHANGED.equals(action)) {
if (bluetoothAdapter.getState() == BluetoothAdapter.STATE_ON) {
System.out.println("--------打开蓝牙-----------");
switchBT.setText("关闭蓝牙");
searchDevices.setEnabled(true);
bondDevicesListView.setEnabled(true);
unbondDevicesListView.setEnabled(true);
} else if (bluetoothAdapter.getState() == BluetoothAdapter.STATE_OFF) {
System.out.println("--------关闭蓝牙-----------");
switchBT.setText("打开蓝牙");
searchDevices.setEnabled(false);
bondDevicesListView.setEnabled(false);
unbondDevicesListView.setEnabled(false);
}
}
}
};
}
到这里，第一个界面的代码就写完了，当我们点击要打印的蓝牙设备时就会跳转到打印页面，跳转代码在BluetoothService.java的addBondDevicesToListView()中
接下来让我们来看看第二个界面的代码，结构和第一个界面的代码一样，分类三个类，请看代码。。。。。
PrintDataActivity.java
**\[java\]** [view plain]( ) [copy]( ) [print]( ) [?]( )
1. public class PrintDataActivity extends Activity {
2. private Context context = null;
4. public void onCreate(Bundle savedInstanceState) {
5. super.onCreate(savedInstanceState);
6. this.setTitle("蓝牙打印");
7. this.setContentView(R.layout.printdata\_layout);
8. this.context = this;
9. this.initListener();
10. }
12. /\*\*
13. \* 获得从上一个Activity传来的蓝牙地址
14. \* @return String
15. \*/
16. private String getDeviceAddress() {
17. // 直接通过Context类的getIntent()即可获取Intent
18. Intent intent = this.getIntent();
19. // 判断
20. if (intent != null) {
21. return intent.getStringExtra("deviceAddress");
22. } else {
23. return null;
24. }
25. }
27. private void initListener() {
28. TextView deviceName = (TextView) this.findViewById(R.id.device\_name);
29. TextView connectState = (TextView) this
30. .findViewById(R.id.connect\_state);
32. PrintDataAction printDataAction = new PrintDataAction(this.context,
33. this.getDeviceAddress(), deviceName, connectState);
35. EditText printData = (EditText) this.findViewById(R.id.print\_data);
36. Button send = (Button) this.findViewById(R.id.send);
37. Button command = (Button) this.findViewById(R.id.command);
38. printDataAction.setPrintData(printData);
40. send.setOnClickListener(printDataAction);
41. command.setOnClickListener(printDataAction);
42. }
45. @Override
46. protected void onDestroy() {
47. PrintDataService.disconnect();
48. super.onDestroy();
49. }
51. }
public class PrintDataActivity extends Activity {
private Context context = null;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setTitle("蓝牙打印");
this.setContentView(R.layout.printdata_layout);
this.context = this;
this.initListener();
}
/**
* 获得从上一个Activity传来的蓝牙地址
* @return String
*/
private String getDeviceAddress() {
// 直接通过Context类的getIntent()即可获取Intent
Intent intent = this.getIntent();
// 判断
if (intent != null) {
return intent.getStringExtra("deviceAddress");
} else {
return null;
}
}
private void initListener() {
TextView deviceName = (TextView) this.findViewById(R.id.device_name);
TextView connectState = (TextView) this
.findViewById(R.id.connect_state);
PrintDataAction printDataAction = new PrintDataAction(this.context,
this.getDeviceAddress(), deviceName, connectState);
EditText printData = (EditText) this.findViewById(R.id.print_data);
Button send = (Button) this.findViewById(R.id.send);
Button command = (Button) this.findViewById(R.id.command);
printDataAction.setPrintData(printData);
send.setOnClickListener(printDataAction);
command.setOnClickListener(printDataAction);
}
@Override
protected void onDestroy() {
PrintDataService.disconnect();
super.onDestroy();
}
}
PrintDataAction.java
**\[java\]** [view plain]( ) [copy]( ) [print]( ) [?]( )
1. <span style="font-size: 14px;"\>public class PrintDataAction implements OnClickListener {
2. private Context context = null;
3. private TextView deviceName = null;
4. private TextView connectState = null;
5. private EditText printData = null;
6. private String deviceAddress = null;
7. private PrintDataService printDataService = null;
9. public PrintDataAction(Context context, String deviceAddress,
10. TextView deviceName, TextView connectState) {
11. super();
12. this.context = context;
13. this.deviceAddress = deviceAddress;
14. this.deviceName = deviceName;
15. this.connectState = connectState;
16. this.printDataService = new PrintDataService(this.context,
17. this.deviceAddress);
18. this.initView();
20. }
22. private void initView() {
23. // 设置当前设备名称
24. this.deviceName.setText(this.printDataService.getDeviceName());
25. // 一上来就先连接蓝牙设备
26. boolean flag = this.printDataService.connect();
27. if (flag == false) {
28. // 连接失败
29. this.connectState.setText("连接失败！");
30. } else {
31. // 连接成功
32. this.connectState.setText("连接成功！");
34. }
35. }
37. public void setPrintData(EditText printData) {
38. this.printData = printData;
39. }
41. @Override
42. public void onClick(View v) {
43. if (v.getId() == R.id.send) {
44. String sendData = this.printData.getText().toString();
45. this.printDataService.send(sendData + "\\n");
46. } else if (v.getId() == R.id.command) {
47. this.printDataService.selectCommand();
49. }
50. }
51. }</span>
public class PrintDataAction implements OnClickListener {
private Context context = null;
private TextView deviceName = null;
private TextView connectState = null;
private EditText printData = null;
private String deviceAddress = null;
private PrintDataService printDataService = null;
public PrintDataAction(Context context, String deviceAddress,
TextView deviceName, TextView connectState) {
super();
this.context = context;
this.deviceAddress = deviceAddress;
this.deviceName = deviceName;
this.connectState = connectState;
this.printDataService = new PrintDataService(this.context,
this.deviceAddress);
this.initView();
}
private void initView() {
// 设置当前设备名称
this.deviceName.setText(this.printDataService.getDeviceName());
// 一上来就先连接蓝牙设备
boolean flag = this.printDataService.connect();
if (flag == false) {
// 连接失败
this.connectState.setText("连接失败！");
} else {
// 连接成功
this.connectState.setText("连接成功！");
}
}
public void setPrintData(EditText printData) {
this.printData = printData;
}
@Override
public void onClick(View v) {
if (v.getId() == R.id.send) {
String sendData = this.printData.getText().toString();
this.printDataService.send(sendData + "\n");
} else if (v.getId() == R.id.command) {
this.printDataService.selectCommand();
}
}
}
PrintDataService.java
**\[java\]** [view plain]( ) [copy]( ) [print]( ) [?]( )
1. <span style="font-size: 14px;"\>public class PrintDataService {
2. private Context context = null;
3. private String deviceAddress = null;
### 总结
最后为了帮助大家深刻理解Android相关知识点的原理以及面试相关知识，这里放上相关的我搜集整理的14套腾讯、字节跳动、阿里、百度等[2020面试真题解析](https://github.com/a120464/Android-P7/blob/master/Android%E5%BC%80%E5%8F%91%E4%B8%8D%E4%BC%9A%E8%BF%99%E4%BA%9B%EF%BC%9F%E5%A6%82%E4%BD%95%E9%9D%A2%E8%AF%95%E6%8B%BF%E9%AB%98%E8%96%AA%EF%BC%81.md)，我把技术点整理成了视频和PDF（实际上比预期多花了不少精力），包知识脉络 + 诸多细节。
网上学习 Android的资料一大堆，但如果学到的知识不成体系，遇到问题时只是浅尝辄止，不再深入研究，那么很难做到真正的技术提升。希望这份[系统化的技术体系](https://github.com/a120464/Android-P7/blob/master/Android%E5%BC%80%E5%8F%91%E4%B8%8D%E4%BC%9A%E8%BF%99%E4%BA%9B%EF%BC%9F%E5%A6%82%E4%BD%95%E9%9D%A2%E8%AF%95%E6%8B%BF%E9%AB%98%E8%96%AA%EF%BC%81.md)对大家有一个方向参考。
