在我的项目中需要通过蓝牙打印机打印Pdf文件。我写了一个代码来打印pdf 它适合文本，
但我想在蓝牙打印机上打印PDF文件。
我的java代码打印文本
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
lv= (ListView) findViewById(R.id.listView1);
// listdata(lv);
try {
// we are goin to have three buttons for specific functions
Button openButton = (Button) findViewById(R.id.open);
Button sendButton = (Button) findViewById(R.id.send);
Button closeButton = (Button) findViewById(R.id.close);
Button btnco= (Button) findViewById(R.id.btnconnect);
btnco.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
try {
findBT();
openBT();
} catch (Exception ex) {
}
}
});
myLabel = (TextView) findViewById(R.id.label);
myTextbox = (EditText) findViewById(R.id.entry);
// open bluetooth connection
openButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
startActivity(new Intent(MainActivity.this,NewAct.class));
}
});
// send data typed by the user to be printed
sendButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
try {
sendData();
} catch (IOException ex) {
}
}
});
// close bluetooth connection
closeButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
try {
closeBT();
} catch (IOException ex) {
}
}
});
} catch (NullPointerException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
/*
* This will find a bluetooth printer device
*/
void findBT() {
try {
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (mBluetoothAdapter == null) {
myLabel.setText("No bluetooth adapter available");
Toast.makeText(MainActivity.this, "No bluetooth available", Toast.LENGTH_LONG).show();
// startActivity(new Intent(MainActivity.this,NewAct.class));
}
if (!mBluetoothAdapter.isEnabled()) {
Intent enableBluetooth = new Intent(
BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBluetooth, 0);
Toast.makeText(this, "OPen", Toast.LENGTH_LONG).show();
//startActivity(new Intent(MainActivity.this,NewAct.class));
}
Set<BluetoothDevice> pairedDevices = mBluetoothAdapter
.getBondedDevices();
if (pairedDevices.size() > 0) {
for (BluetoothDevice device : pairedDevices) {
// MP300 is the name of the bluetooth printer device
if (device.getName().equals(NewAct.printer)) {
//openBT();
mmDevice = device;
break;
}
else {
}
}
}
{
myLabel.setText("Bluetooth Device Found");
try {
// Standard SerialPortService ID
UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805f9b34fb");
mmSocket = mmDevice.createRfcommSocketToServiceRecord(uuid);
mmSocket.connect();
mmOutputStream = mmSocket.getOutputStream();
mmInputStream = mmSocket.getInputStream();
beginListenForData();
myLabel.setText("Bluetooth Opened");
} catch (NullPointerException e) {
e.printStackTrace();
}
}
} catch (NullPointerException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
/*
* Tries to open a connection to the bluetooth printer device
*/
void openBT() throws IOException {
try {
// Standard SerialPortService ID
UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805f9b34fb");
mmSocket = mmDevice.createRfcommSocketToServiceRecord(uuid);
mmSocket.connect();
mmOutputStream = mmSocket.getOutputStream();
mmInputStream = mmSocket.getInputStream();
beginListenForData();
myLabel.setText("Bluetooth Opened");
} catch (NullPointerException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
/*
* After opening a connection to bluetooth printer device,
* we have to listen and check if a data were sent to be printed.
*/
void beginListenForData() {
try {
final Handler handler = new Handler();
// This is the ASCII code for a newline character
final byte delimiter = 10;
stopWorker = false;
readBufferPosition = 0;
readBuffer = new byte[1024];
workerThread = new Thread(new Runnable() {
public void run() {
while (!Thread.currentThread().isInterrupted()
&& !stopWorker) {
try {
int bytesAvailable = mmInputStream.available();
if (bytesAvailable > 0) {
byte[] packetBytes = new byte[bytesAvailable];
mmInputStream.read(packetBytes);
for (int i = 0; i < bytesAvailable; i++) {
byte b = packetBytes[i];
if (b == delimiter) {
byte[] encodedBytes = new byte[readBufferPosition];
System.arraycopy(readBuffer, 0,
encodedBytes, 0,
encodedBytes.length);
final String data = new String(
encodedBytes, "US-ASCII");
readBufferPosition = 0;
handler.post(new Runnable() {
public void run() {
myLabel.setText(data);
}
});
} else {
readBuffer[readBufferPosition++] = b;
}
}
}
} catch (IOException ex) {
stopWorker = true;
}
}
}
});
workerThread.start();
} catch (NullPointerException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
/*
* This will send data to be printed by the bluetooth printer
*/
void sendData() throws IOException {
try {
// the text typed by the user
String msg = myTextbox.getText().toString();
msg += "\n";
mmOutputStream.write(msg.getBytes());
// tell the user data were sent
myLabel.setText("Data Sent");
} catch (NullPointerException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
/*
* Close the connection to bluetooth printer.
*/
void closeBT() throws IOException {
try {
stopWorker = true;
mmOutputStream.close();
mmInputStream.close();
mmSocket.close();
myLabel.setText("Bluetooth Closed");
} catch (NullPointerException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
public void listdata(ListView lv){
try{
pairedDevices = mBluetoothAdapter.getBondedDevices();
ArrayList<String> list = new ArrayList<String>();
for(BluetoothDevice bt : pairedDevices)
list.add(bt.getName());
Toast.makeText(getApplicationContext(),"Showing Paired Devices",
Toast.LENGTH_SHORT).show();
@SuppressWarnings("unchecked")
final ArrayAdapter<String> adapter = new ArrayAdapter<String>
(this,android.R.layout.simple_list_item_1, list);
lv.setAdapter(adapter);
}catch(Exception e)
{
Toast.makeText(this, "error"+e, Toast.LENGTH_LONG).show();
}
}
我没有想法如何将Pdf文件传递给蓝牙打印机
请帮助我如何做到这一点
提前致谢。
答案 0 :(得分：1)
您可以尝试使用Android意图打开pdf，如果可以从其他应用程序打印它（可能是制造商自己的？）
Intent intent = new Intent();
intent.setAction(android.content.Intent.ACTION_VIEW);
intent.setDataAndType(Uri.fromFile(file), "application/pdf");
c.startActivity(intent);
答案 1 :(得分：0)
大多数蓝牙打印机不支持开箱即用打印PDF。
您需要做的是使用Android打印机框架或任何其他库/类（如PDFRenderer）将PDF页面转换为图像，并使用打印机能够识别的仿真将这些图像发送到打印机（来自ZPL， CPCL，PCL-3等）
答案 2 :(得分：-1)
任何应用程序打印pdf都有一些库来解码pdf。
当然，您只能向打印机发送文字。
如果你想直接打印pdf，你需要自己的库才能做到这一点。
对于android我总是使用mupdf，非常强大的lib和开源。
查看stackoverflow如何逐步安装Integrate MuPDF Reader in an app
完成从https://github.com/derek-watson/mupdf 运行完整演示项目后的目录上的
列表（mupdf / platform / android /）
从你将要显示的设备中选择pdf后，它将运行主要活动ChoosePDFActivity.java，然后主要顶部栏有打印按钮（PrintDialogActivity.java在google云打印上打印）更改此处的代码以将流发送到打印机
希望这有帮助!!!