Android 中的蓝牙打印机问题

Question

我正在尝试使用以下代码通过蓝牙打印账单， 当我运行该应用程序时，第一次它被打印，但是当我重试时它没有被打印。

package com.sel.bluetooth;

import java.io.OutputStream;
import java.lang.reflect.Method;

import android.app.Activity;
import android.app.Dialog;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;

public class BluetoothPrint extends Activity {

    BluetoothAdapter mBTAdapter;
    BluetoothSocket mBTSocket = null;
    Dialog dialogProgress;
    String BILL, TRANS_ID;
    String PRINTER_MAC_ID;
    final String ERROR_MESSAGE = "There has been an error in printing the bill.";

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        try {

            // BILL = getIntent().getStringExtra("TO_PRINT");
            // TRANS_ID = getIntent().getStringExtra("TRANS_ID");

            // PRINTER_MAC_ID = getIntent().getStringExtra("MAC_ID");
            PRINTER_MAC_ID = "00:1F:B7:02:8F:44";
            //PRINTER_MAC_ID = "00:12:F3:0D:A3:E6";
            // TRANS_ID="12345678";
            BILL = "\nSale Slip No: 12345678" + "          " + "04-08-2011\n";
            BILL = BILL + "----------------------------------------";
            BILL = BILL + "\n\n";
            BILL = BILL + "Total Qty:" + "     " + "2.0\n";
            BILL = BILL + "Total Value:" + "     " + "17625.0\n";
            BILL = BILL + "-----------------------------------------";

            mBTAdapter = BluetoothAdapter.getDefaultAdapter();
            dialogProgress = new Dialog(BluetoothPrint.this);

            try {
                if (mBTAdapter.isDiscovering())
                    mBTAdapter.cancelDiscovery();
                else
                    mBTAdapter.startDiscovery();
            } catch (Exception e) {
                Log.e("Class ", "My Exe ", e);
            }
            System.out.println("BT Searching status :"
                    + mBTAdapter.isDiscovering());
            if (mBTAdapter == null) {
                Toast.makeText(this, "Device has no bluetooth capability",
                        Toast.LENGTH_LONG).show();
                finish();
            } else {
                if (!mBTAdapter.isEnabled()) {
                    Intent i = new Intent(
                            BluetoothAdapter.ACTION_REQUEST_ENABLE);
                    startActivityForResult(i, 0);
                }

                // Register the BroadcastReceiver
                IntentFilter filter = new IntentFilter(
                        BluetoothDevice.ACTION_FOUND);
                registerReceiver(mReceiver, filter); // Don't forget to
                                                        // unregister during
                                                        // onDestroy
                dialogProgress.setTitle("Finding printer...");
                dialogProgress
                        .setOnDismissListener(new DialogInterface.OnDismissListener() {
                            public void onDismiss(DialogInterface dialog) {
                                dialog.dismiss();
                                setResult(RESULT_CANCELED);
                                finish();
                            }
                        });
                dialogProgress.show();

            }

        } catch (Exception e) {
            Log.e("Class ", "My Exe ", e);
        }
    }

    public void printBillToDevice(final String address) {
        new Thread(new Runnable() {

            public void run() {
                runOnUiThread(new Runnable() {

                    public void run() {
                        dialogProgress.setTitle("Connecting...");
                        dialogProgress.show();
                    }

                });

                mBTAdapter.cancelDiscovery();

                try {
                    System.out
                            .println("**************************#****connecting");
                    BluetoothDevice mdevice = mBTAdapter
                            .getRemoteDevice(address);
                    Method m = mdevice.getClass().getMethod(
                            "createRfcommSocket", new Class[] { int.class });
                    mBTSocket = (BluetoothSocket) m.invoke(mdevice, 1);

                    mBTSocket.connect();
                    OutputStream os = mBTSocket.getOutputStream();
                    os.flush();

                    os.write(BILL.getBytes());
                    System.out.println(BILL);


                    //mBTSocket.close();
                    setResult(RESULT_OK);
                    finish();
                } catch (Exception e) {
                    Log.e("Class ", "My Exe ", e);
                    //Toast.makeText(BluetoothPrint.this, ERROR_MESSAGE,            Toast.LENGTH_SHORT).show();
                    e.printStackTrace();
                    setResult(RESULT_CANCELED);
                    finish();

                }

                runOnUiThread(new Runnable() {

                    public void run() {
                        try {
                            dialogProgress.dismiss();
                        } catch (Exception e) {
                            Log.e("Class ", "My Exe ", e);
                        }
                    }

                });

            }

        }).start();
    }

    @Override
    protected void onDestroy() {
        Log.i("Dest ", "Checking Ddest");
        super.onDestroy();
        try {
            if(dialogProgress != null)
                dialogProgress.dismiss();
            if (mBTAdapter != null)
                mBTAdapter.cancelDiscovery();
            this.unregisterReceiver(mReceiver);
        } catch (Exception e) {
            Log.e("Class ", "My Exe ", e);
        }
    }

    private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
        public void onReceive(Context context, Intent intent) {

            try {
                String action = intent.getAction();
                // When discovery finds a device
                if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                    // Get the BluetoothDevice object from the Intent
                    BluetoothDevice device = intent
                            .getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                    System.out.println("***" + device.getName() + " : "
                            + device.getAddress());

                    if (device.getAddress().equalsIgnoreCase(PRINTER_MAC_ID)) {
                        mBTAdapter.cancelDiscovery();
                        dialogProgress.dismiss();
                        Toast.makeText(BluetoothPrint.this,
                                device.getName() + " Printing data",
                                Toast.LENGTH_LONG).show();
                        printBillToDevice(PRINTER_MAC_ID);
                        Toast.makeText(BluetoothPrint.this,
                                device.getName() + " found", Toast.LENGTH_LONG)
                                .show();
                    }
                }
            } catch (Exception e) {
                Log.e("Class  ", "My Exe ", e);
                //Toast.makeText(BluetoothPrint.this, ERROR_MESSAGE,                        Toast.LENGTH_SHORT).show();

            }
        }
    };

    @Override
    public void onBackPressed() {
        try {
            if (mBTAdapter != null)
                mBTAdapter.cancelDiscovery();
            this.unregisterReceiver(mReceiver);
        } catch (Exception e) {
            Log.e("Class ", "My Exe ", e);
        }
        setResult(RESULT_CANCELED);
        finish();
    }

}

Answer 1

中蓝牙打印机完美工作的代码

这是 android device_list.xml

    <?xml version="1.0" encoding="utf-8"?> 
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:orientation="vertical" android:layout_width="fill_parent" 
    android:layout_height="fill_parent"> 
    <TextView android:id="@+id/title_paired_devices" 
    android:layout_width="fill_parent" android:layout_height="wrap_content" 
    android:text="My Text" android:visibility="gone" 
    android:background="#666" android:textColor="#fff" 
    android:paddingLeft="5dip" /> 
    <ListView android:id="@+id/paired_devices" 
    android:layout_width="fill_parent" android:layout_height="wrap_content" 
    android:stackFromBottom="true" android:layout_weight="1" /> 
    </LinearLayout>

device_name.xml

    <?xml version="1.0" encoding="utf-8"?> 
    <TextView xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" android:layout_height="wrap_content" 
    android:textSize="18sp" android:padding="5dip" /> 

main.xml

<?xml version="1.0" encoding="utf-8"?>
        <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:orientation="vertical" android:layout_width="fill_parent"
        android:layout_height="fill_parent">
        <TextView android:layout_width="fill_parent"
        android:layout_height="wrap_content" android:text="@string/hello" />
        <Button android:text="Scan" android:id="@+id/Scan"
        android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
        <Button android:text="Print" android:id="@+id/mPrint"
        android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
        <Button android:text="Dissable" android:id="@+id/dis"
        android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
        </LinearLayout>

DeviceListActivity.java

    package com.sel.code;

    import java.util.Set; 
          import android.app.Activity; 
          import android.bluetooth.BluetoothAdapter; 
          import android.bluetooth.BluetoothDevice; 
          import android.content.Intent; 
          import android.os.Bundle; 
          import android.util.Log; 
          import android.view.View; 
          import android.view.Window; 
          import android.widget.AdapterView; 
          import android.widget.ArrayAdapter; 
          import android.widget.ListView; 
          import android.widget.TextView; 
          import android.widget.AdapterView.OnItemClickListener; 

    public class DeviceListActivity extends Activity 
    { 
    protected static final String TAG = "TAG"; 
    private BluetoothAdapter mBluetoothAdapter; 
    private ArrayAdapter<String> mPairedDevicesArrayAdapter; 

    @Override 
    protected void onCreate(Bundle mSavedInstanceState) 
    { 
        super.onCreate(mSavedInstanceState); 
        requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS); 
        setContentView(R.layout.device_list); 

        setResult(Activity.RESULT_CANCELED); 
        mPairedDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.device_name); 

        ListView mPairedListView = (ListView) findViewById(R.id.paired_devices); 
        mPairedListView.setAdapter(mPairedDevicesArrayAdapter); 
        mPairedListView.setOnItemClickListener(mDeviceClickListener); 

        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter(); 
        Set<BluetoothDevice> mPairedDevices = mBluetoothAdapter.getBondedDevices(); 

        if (mPairedDevices.size() > 0) 
        { 
            findViewById(R.id.title_paired_devices).setVisibility(View.VISIBLE); 
            for (BluetoothDevice mDevice : mPairedDevices) 
            { 
                mPairedDevicesArrayAdapter.add(mDevice.getName() + "\n" + mDevice.getAddress()); 
            } 
        } 
        else 
        { 
            String mNoDevices = "None Paired";//getResources().getText(R.string.none_paired).toString(); 
            mPairedDevicesArrayAdapter.add(mNoDevices); 
        } 
    } 

    @Override 
    protected void onDestroy() 
    { 
        super.onDestroy(); 
        if (mBluetoothAdapter != null) 
        { 
            mBluetoothAdapter.cancelDiscovery(); 
        } 
    } 

    private OnItemClickListener mDeviceClickListener = new OnItemClickListener() 
    { 
        public void onItemClick(AdapterView<?> mAdapterView, View mView, int mPosition, long mLong) 
        { 
            mBluetoothAdapter.cancelDiscovery(); 
            String mDeviceInfo = ((TextView) mView).getText().toString(); 
            String mDeviceAddress = mDeviceInfo.substring(mDeviceInfo.length() - 17); 
            Log.v(TAG, "Device_Address " + mDeviceAddress); 

            Bundle mBundle = new Bundle(); 
            mBundle.putString("DeviceAddress", mDeviceAddress); 
            Intent mBackIntent = new Intent(); 
            mBackIntent.putExtras(mBundle); 
            setResult(Activity.RESULT_OK, mBackIntent); 
            finish(); 
        } 
    }; 

     } 

Main.java

        package com.sel.code;

        import java.io.IOException;
        import java.io.OutputStream;
        import java.nio.ByteBuffer;
        import java.util.Set;
        import java.util.UUID;

        import android.app.Activity;
        import android.app.ProgressDialog;
        import android.bluetooth.BluetoothAdapter;
        import android.bluetooth.BluetoothDevice;
        import android.bluetooth.BluetoothSocket;
        import android.content.Intent;
        import android.os.Bundle;
        import android.os.Handler;
        import android.os.Message;
        import android.util.Log;
        import android.view.View;
        import android.view.Window;
        import android.view.WindowManager;
        import android.widget.Button;
        import android.widget.Toast;

        public class Main extends Activity implements Runnable {
            protected static final String TAG = "TAG";
            private static final int REQUEST_CONNECT_DEVICE = 1;
            private static final int REQUEST_ENABLE_BT = 2;
            Button mScan, mPrint, mDisc;
            BluetoothAdapter mBluetoothAdapter;
            private UUID applicationUUID = UUID
                    .fromString("00001101-0000-1000-8000-00805F9B34FB");
            private ProgressDialog mBluetoothConnectProgressDialog;
            private BluetoothSocket mBluetoothSocket;
            BluetoothDevice mBluetoothDevice;

            @Override
            public void onCreate(Bundle mSavedInstanceState) {
                super.onCreate(mSavedInstanceState);
                requestWindowFeature(Window.FEATURE_NO_TITLE);
                getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                        WindowManager.LayoutParams.FLAG_FULLSCREEN);
                setContentView(R.layout.main);
                mScan = (Button) findViewById(R.id.Scan);
                mScan.setOnClickListener(new View.OnClickListener() {
                    public void onClick(View mView) {
                        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
                        if (mBluetoothAdapter == null) {
                            Toast.makeText(Main.this, "Message1", 2000).show();
                        } else {
                            if (!mBluetoothAdapter.isEnabled()) {
                                Intent enableBtIntent = new Intent(
                                        BluetoothAdapter.ACTION_REQUEST_ENABLE);
                                startActivityForResult(enableBtIntent,
                                        REQUEST_ENABLE_BT);
                            } else {
                                ListPairedDevices();
                                Intent connectIntent = new Intent(Main.this,
                                        DeviceListActivity.class);
                                startActivityForResult(connectIntent,
                                        REQUEST_CONNECT_DEVICE);
                            }
                        }
                    }
                });

                mPrint = (Button) findViewById(R.id.mPrint);
                mPrint.setOnClickListener(new View.OnClickListener() {
                    public void onClick(View mView) {
                        Thread t = new Thread() {
                            public void run() {
                                try {
                                    OutputStream os = mBluetoothSocket
                                            .getOutputStream();
                                    String BILL = "";

                                    BILL = "\nInvoice No: ABCDEF28060000005" + "    "
                                            + "04-08-2011\n";
                                    BILL = BILL
                                            + "-----------------------------------------";
                                    BILL = BILL + "\n\n";
                                    BILL = BILL + "Total Qty:" + "      " + "2.0\n";
                                    BILL = BILL + "Total Value:" + "     "
                                            + "17625.0\n";
                                    BILL = BILL
                                            + "-----------------------------------------\n";
                                    os.write(BILL.getBytes());
                                        //This is printer specific code you can comment ==== > Start

                                    // Setting height
                                    int gs = 29;
                                    os.write(intToByteArray(gs));
                                    int h = 104;
                                    os.write(intToByteArray(h));
                                    int n = 162;
                                    os.write(intToByteArray(n));

                                    // Setting Width
                                    int gs_width = 29;
                                    os.write(intToByteArray(gs_width));
                                    int w = 119;
                                    os.write(intToByteArray(w));
                                    int n_width = 2;
                                    os.write(intToByteArray(n_width));

                                    // Print BarCode
                                    int gs1 = 29;
                                    os.write(intToByteArray(gs1));
                                    int k = 107;
                                    os.write(intToByteArray(k));
                                    int m = 73;
                                    os.write(intToByteArray(m));

                                    String barCodeVal = "ASDFC028060000005";// "HELLO12345678912345012";
                                    System.out.println("Barcode Length : "
                                            + barCodeVal.length());
                                    int n1 = barCodeVal.length();
                                    os.write(intToByteArray(n1));

                                    for (int i = 0; i < barCodeVal.length(); i++) {
                                        os.write((barCodeVal.charAt(i) + "").getBytes());
                                    }
       //printer specific code you can comment ==== > End
                                } catch (Exception e) {
                                    Log.e("Main", "Exe ", e);
                                }
                            }
                        };
                        t.start();
                    }
                });

                mDisc = (Button) findViewById(R.id.dis);
                mDisc.setOnClickListener(new View.OnClickListener() {
                    public void onClick(View mView) {
                        if (mBluetoothAdapter != null)
                            mBluetoothAdapter.disable();
                    }
                });

            }// onCreate

            @Override
            protected void onDestroy() {
                // TODO Auto-generated method stub
                super.onDestroy();
                try {
                    if (mBluetoothSocket != null)
                        mBluetoothSocket.close();
                } catch (Exception e) {
                    Log.e("Tag", "Exe ", e);
                }
            }

            @Override
            public void onBackPressed() {
                try {
                    if (mBluetoothSocket != null)
                        mBluetoothSocket.close();
                } catch (Exception e) {
                    Log.e("Tag", "Exe ", e);
                }
                setResult(RESULT_CANCELED);
                finish();
            }

            public void onActivityResult(int mRequestCode, int mResultCode,
                    Intent mDataIntent) {
                super.onActivityResult(mRequestCode, mResultCode, mDataIntent);

                switch (mRequestCode) {
                case REQUEST_CONNECT_DEVICE:
                    if (mResultCode == Activity.RESULT_OK) {
                        Bundle mExtra = mDataIntent.getExtras();
                        String mDeviceAddress = mExtra.getString("DeviceAddress");
                        Log.v(TAG, "Coming incoming address " + mDeviceAddress);
                        mBluetoothDevice = mBluetoothAdapter
                                .getRemoteDevice(mDeviceAddress);
                        mBluetoothConnectProgressDialog = ProgressDialog.show(this,
                                "Connecting...", mBluetoothDevice.getName() + " : "
                                        + mBluetoothDevice.getAddress(), true, false);
                        Thread mBlutoothConnectThread = new Thread(this);
                        mBlutoothConnectThread.start();
                        // pairToDevice(mBluetoothDevice); This method is replaced by
                        // progress dialog with thread
                    }
                    break;

                case REQUEST_ENABLE_BT:
                    if (mResultCode == Activity.RESULT_OK) {
                        ListPairedDevices();
                        Intent connectIntent = new Intent(Main.this,
                                DeviceListActivity.class);
                        startActivityForResult(connectIntent, REQUEST_CONNECT_DEVICE);
                    } else {
                        Toast.makeText(Main.this, "Message", 2000).show();
                    }
                    break;
                }
            }

            private void ListPairedDevices() {
                Set<BluetoothDevice> mPairedDevices = mBluetoothAdapter
                        .getBondedDevices();
                if (mPairedDevices.size() > 0) {
                    for (BluetoothDevice mDevice : mPairedDevices) {
                        Log.v(TAG, "PairedDevices: " + mDevice.getName() + "  "
                                + mDevice.getAddress());
                    }
                }
            }

            public void run() {
                try {
                    mBluetoothSocket = mBluetoothDevice
                            .createRfcommSocketToServiceRecord(applicationUUID);
                    mBluetoothAdapter.cancelDiscovery();
                    mBluetoothSocket.connect();
                    mHandler.sendEmptyMessage(0);
                } catch (IOException eConnectException) {
                    Log.d(TAG, "CouldNotConnectToSocket", eConnectException);
                    closeSocket(mBluetoothSocket);
                    return;
                }
            }

            private void closeSocket(BluetoothSocket nOpenSocket) {
                try {
                    nOpenSocket.close();
                    Log.d(TAG, "SocketClosed");
                } catch (IOException ex) {
                    Log.d(TAG, "CouldNotCloseSocket");
                }
            }

            private Handler mHandler = new Handler() {
                @Override
                public void handleMessage(Message msg) {
                    mBluetoothConnectProgressDialog.dismiss();
                    Toast.makeText(Main.this, "DeviceConnected", 5000).show();
                }
            };

            public static byte intToByteArray(int value) {
                byte[] b = ByteBuffer.allocate(4).putInt(value).array();

                for (int k = 0; k < b.length; k++) {
                    System.out.println("Selva  [" + k + "] = " + "0x"
                            + UnicodeFormatter.byteToHex(b[k]));
                }

                return b[3];
            }

            public byte[] sel(int val) {
                ByteBuffer buffer = ByteBuffer.allocate(2);
                buffer.putInt(val);
                buffer.flip();
                return buffer.array();
            }

        }

UnicodeFormatter.java

    package com.sel.code;

    import java.io.*;

    public class UnicodeFormatter {

        static public String byteToHex(byte b) {
                // Returns hex String representation of byte b
                char hexDigit[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
                        'a', 'b', 'c', 'd', 'e', 'f' };
                char[] array = { hexDigit[(b >> 4) & 0x0f], hexDigit[b & 0x0f] };
                return new String(array);
        }

        static public String charToHex(char c) {
                // Returns hex String representation of char c
                byte hi = (byte) (c >>> 8);
                byte lo = (byte) (c & 0xff);
                return byteToHex(hi) + byteToHex(lo);
        }

    } // class

Answer 2

我刚刚取消注释 //mBTSocket.close();

然后，就在之前，添加：

if (mBTAdapter != null)
    mBTAdapter.cancelDiscovery();

一切顺利！

Answer 3

还可以尝试在写入后关闭 OutputStream，最好在完成块中使用：

os.close();