android - 如何在android中通过蓝牙连接手机和打印机？

Question

谁能告诉我如何通过蓝牙连接手机和打印机以在android中打印文本文件？

也就是说，如果我从 android 应用程序中单击打印按钮，打印机必须打印相应的文件。据我所知，我已经在 Google 中搜索过它，但我找不到任何好的示例来执行此操作.有没有人有至少一个示例 android 程序来执行此操作，最好清除我的困惑。

请多多指教。感谢您的宝贵时间!..

Answer 1

蓝牙打印机 Android 示例在您的编辑器中创建一个新的 android 项目 BlueToothPrinterApp。

第一步:

像下面这样创建主要 Activity

com.example.BlueToothPrinterApp / BlueToothPrinterApp.java

package com.example.BlueToothPrinterApp;

import android.app.Activity;
import android.os.Bundle;
import java.io.IOException;
import java.io.OutputStream;
import android.bluetooth.BluetoothSocket;
import android.content.ContentValues;
import android.content.Intent;
import android.os.Environment;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class BlueToothPrinterApp extends Activity {
    /** Called when the activity is first created. */
    EditText message;
    Button printbtn;

    byte FONT_TYPE;
    private static BluetoothSocket btsocket;
    private static OutputStream btoutputstream;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        message = (EditText) findViewById(R.id.message);
        printbtn = (Button) findViewById(R.id.printButton);

        printbtn.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                connect();
            }
        });
    }

    protected void connect() {
        if (btsocket == null) {
            Intent BTIntent = new Intent(getApplicationContext(), BTDeviceList.class);
            this.startActivityForResult(BTIntent, BTDeviceList.REQUEST_CONNECT_BT);
        } else {

            OutputStream opstream = null;
            try {
                opstream = btsocket.getOutputStream();
            } catch (IOException e) {
                e.printStackTrace();
            }
            btoutputstream = opstream;
            print_bt();

        }

    }
    private void print_bt() {
        try {
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

            btoutputstream = btsocket.getOutputStream();

            byte[] printformat = {
                0x1B,
                0× 21,
                FONT_TYPE
            };
            btoutputstream.write(printformat);
            String msg = message.getText().toString();
            btoutputstream.write(msg.getBytes());
            btoutputstream.write(0x0D);
            btoutputstream.write(0x0D);
            btoutputstream.write(0x0D);
            btoutputstream.flush();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        try {
            if (btsocket != null) {
                btoutputstream.close();
                btsocket.close();
                btsocket = null;
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        try {
            btsocket = BTDeviceList.getSocket();
            if (btsocket != null) {
                print_bt();
            }

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

第 2 步:

com.example.BlueToothPrinterApp / BTDeviceList.java

package com.example.BlueToothPrinterApp;

import java.io.IOException;
import java.util.Set;
import java.util.UUID;

import android.app.ListActivity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
public class BTDeviceList extends ListActivity {

    static public final int REQUEST_CONNECT_BT = 0× 2300;

    static private final int REQUEST_ENABLE_BT = 0× 1000;

    static private BluetoothAdapter mBluetoothAdapter = null;

    static private ArrayAdapter < String > mArrayAdapter = null;

    static private ArrayAdapter < BluetoothDevice > btDevices = null;

    private static final UUID SPP_UUID = UUID
        .fromString(“8 ce255c0 - 200 a - 11e0 - ac64 - 0800200 c9a66″);
    // UUID.fromString(“00001101-0000-1000-8000-00805F9B34FB”);

    static private BluetoothSocket mbtSocket = null;

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

        setTitle(“Bluetooth Devices”);

        try {
            if (initDevicesList() != 0) {
                this.finish();
                return;
            }

        } catch (Exception ex) {
            this.finish();
            return;
        }

        IntentFilter btIntentFilter = new IntentFilter(
            BluetoothDevice.ACTION_FOUND);
        registerReceiver(mBTReceiver, btIntentFilter);
    }

    public static BluetoothSocket getSocket() {
        return mbtSocket;
    }

    private void flushData() {
        try {
            if (mbtSocket != null) {
                mbtSocket.close();
                mbtSocket = null;
            }

            if (mBluetoothAdapter != null) {
                mBluetoothAdapter.cancelDiscovery();
            }

            if (btDevices != null) {
                btDevices.clear();
                btDevices = null;
            }

            if (mArrayAdapter != null) {
                mArrayAdapter.clear();
                mArrayAdapter.notifyDataSetChanged();
                mArrayAdapter.notifyDataSetInvalidated();
                mArrayAdapter = null;
            }

            finalize();

        } catch (Exception ex) {} catch (Throwable e) {}

    }
    private int initDevicesList() {

        flushData();

        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        if (mBluetoothAdapter == null) {
            Toast.makeText(getApplicationContext(), “Bluetooth not supported!!”, Toast.LENGTH_LONG).show();
            return -1;
        }

        if (mBluetoothAdapter.isDiscovering()) {
            mBluetoothAdapter.cancelDiscovery();
        }

        mArrayAdapter = new ArrayAdapter < String > (getApplicationContext(),
            android.R.layout.simple_list_item_1);

        setListAdapter(mArrayAdapter);

        Intent enableBtIntent = new Intent(
            BluetoothAdapter.ACTION_REQUEST_ENABLE);
        try {
            startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
        } catch (Exception ex) {
            return -2;
        }

        Toast.makeText(getApplicationContext(), “Getting all available Bluetooth Devices”, Toast.LENGTH_SHORT)
            .show();

        return 0;

    }

    @Override
    protected void onActivityResult(int reqCode, int resultCode, Intent intent) {
        super.onActivityResult(reqCode, resultCode, intent);

        switch (reqCode) {
            case REQUEST_ENABLE_BT:

                if (resultCode == RESULT_OK) {
                    Set < BluetoothDevice > btDeviceList = mBluetoothAdapter
                        .getBondedDevices();
                    try {
                        if (btDeviceList.size() > 0) {

                            for (BluetoothDevice device: btDeviceList) {
                                if (btDeviceList.contains(device) == false) {

                                    btDevices.add(device);

                                    mArrayAdapter.add(device.getName() + “\n” +
                                        device.getAddress());
                                    mArrayAdapter.notifyDataSetInvalidated();
                                }
                            }
                        }
                    } catch (Exception ex) {}
                }

                break;
        }

        mBluetoothAdapter.startDiscovery();

    }

    private final BroadcastReceiver mBTReceiver = new BroadcastReceiver() {

        @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);

                try {
                    if (btDevices == null) {
                        btDevices = new ArrayAdapter < BluetoothDevice > (
                            getApplicationContext(), android.R.id.text1);
                    }

                    if (btDevices.getPosition(device) < 0) {
                        btDevices.add(device);
                        mArrayAdapter.add(device.getName() + “\n” +
                            device.getAddress() + “\n”);
                        mArrayAdapter.notifyDataSetInvalidated();
                    }
                } catch (Exception ex) {
                    // ex.fillInStackTrace();
                }
            }
        }
    };

    @Override
    protected void onListItemClick(ListView l, View v, final int position,
        long id) {
        super.onListItemClick(l, v, position, id);

        if (mBluetoothAdapter == null) {
            return;
        }

        if (mBluetoothAdapter.isDiscovering()) {
            mBluetoothAdapter.cancelDiscovery();
        }

        Toast.makeText(
            getApplicationContext(), “Connecting to” + btDevices.getItem(position).getName() + “, ”
            +btDevices.getItem(position).getAddress(),
            Toast.LENGTH_SHORT).show();

        Thread connectThread = new Thread(new Runnable() {

            @Override
            public void run() {
                try {
                    boolean gotuuid = btDevices.getItem(position)
                        .fetchUuidsWithSdp();
                    UUID uuid = btDevices.getItem(position).getUuids()[0]
                        .getUuid();
                    mbtSocket = btDevices.getItem(position)
                        .createRfcommSocketToServiceRecord(uuid);

                    mbtSocket.connect();
                } catch (IOException ex) {
                    runOnUiThread(socketErrorRunnable);
                    try {
                        mbtSocket.close();
                    } catch (IOException e) {
                        // e.printStackTrace();
                    }
                    mbtSocket = null;
                    return;
                } finally {
                    runOnUiThread(new Runnable() {

                        @Override
                        public void run() {
                            finish();

                        }
                    });
                }
            }
        });

        connectThread.start();
    }

    private Runnable socketErrorRunnable = new Runnable() {

        @Override
        public void run() {
            Toast.makeText(getApplicationContext(), “Cannot establish connection”, Toast.LENGTH_SHORT).show();
            mBluetoothAdapter.startDiscovery();

        }
    };

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        super.onCreateOptionsMenu(menu);

        menu.add(0, Menu.FIRST, Menu.NONE, “Refresh Scanning”);

        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        super.onOptionsItemSelected(item);

        switch (item.getItemId()) {
            case Menu.FIRST:
                initDevicesList();
                break;
        }

        return true;
    }
}

第 3 步:

编辑您的 main.xml 文件并粘贴以下代码。

res/layout/main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:paddingLeft="16dp"
    android:paddingRight="16dp">

    <TextView
        android:id="@+id/msgtextlbl"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Enter Your Message : "/>

    <EditText
        android:id="@+id/message"
        android:layout_width="fill_parent"
        android:layout_height="100dp"
        android:layout_below="@+id/msgtextlbl"
        android:text=""/>

    <Button
        android:id="@+id/printButton"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/message"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="5dip"
        android:text="Print"/>

</RelativeLayout>

第四步:

现在编辑你的 AndroidManifest.xml

添加蓝牙权限和管理员权限。

AndroidManifest.xml

<?xml version=”1.0″ encoding=”utf-8″?>
<manifest
    xmlns:android=”http://schemas.android.com/apk/res/android
    package=”com.example.BlueToothPrinterApp”
    android:versionCode=”1″
    android:versionName=”1.0″>

    <uses-sdk android:minSdkVersion=”14″ />
    <uses-permission android:name=”android.permission.BLUETOOTH”></uses-permission>
    <uses-permission android:name=”android.permission.BLUETOOTH_ADMIN”></uses-permission>

    <application
        android:label=”@string/app_name”
        android:icon=”@drawable/ic_launcher”>
        
        <activity
            android:name=”BlueToothPrinterApp”
            android:label=”@string/app_name”>
            
            <intent-filter>
                <action android:name=”android.intent.action.MAIN” />
                <category android:name=”android.intent.category.LAUNCHER” />
            </intent-filter>
        
        </activity>
        
        <activity android:name=”BTDeviceList”></activity>
    
    </application>

</manifest>

编译并运行这个应用程序。输入消息并按打印按钮。

您将看到蓝牙设备列表。选择蓝牙打印机。

检查蓝牙打印机上的打印。

here is the CODE Reference...