Question

我正在使用SimpleBluetoothLibrary访问我的蓝牙打印机。现在我可以搜索可用的设备，从列表中选择蓝牙打印机，连接到打印机。这些部件已完成。但我不知道如何将数据发送到打印机对于打印作业。这是onDeviceConnected方法。我从中获得了设备地址。但我想将数据发送到打印机。

@Override
            public void onDeviceConnected(BluetoothDevice device) {
                //a device is connected so you can now send stuff to it
                mTxt.setText("Connection Status:Connected:" + device.getAddress());

                Log.d("Mac_Address", device.getAddress());


            }

Answer 1

有一个从蓝牙发送数据的简单示例。我希望它对您有帮助。

<强> MainActivity.java

package com.example.bluetoothprinter;

import android.app.Activity;
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.view.View;
import android.widget.TextView;
import android.widget.EditText;
import android.widget.Button;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Set;
import java.util.UUID;

public class MainActivity extends Activity {

// will show the statuses
TextView myLabel;

// will enable user to enter any text to be printed
EditText myTextbox;

// android built in classes for bluetooth operations
BluetoothAdapter mBluetoothAdapter;
BluetoothSocket mmSocket;
BluetoothDevice mmDevice;

OutputStream mmOutputStream;
InputStream mmInputStream;
Thread workerThread;

byte[] readBuffer;
int readBufferPosition;
int counter;
volatile boolean stopWorker;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    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);

        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) {
                try {
                    findBT();
                    openBT();
                } catch (IOException ex) {
                }
            }
        });

        // 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");
        }

        if (!mBluetoothAdapter.isEnabled()) {
            Intent enableBluetooth = new Intent(
                    BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(enableBluetooth, 0);
        }

        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("MP300")) {
                    mmDevice = device;
                    break;
                }
            }
        }
        myLabel.setText("Bluetooth Device Found");
    } 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();
    }
  }
}

<强> activity_main.xml中

<?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" >

<TextView
    android:id="@+id/label"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="Type here:" />

<EditText
    android:id="@+id/entry"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_below="@id/label"
    android:background="@android:drawable/editbox_background" />

<Button
    android:id="@+id/open"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentRight="true"
    android:layout_below="@id/entry"
    android:layout_marginLeft="10dip"
    android:text="Open" />

<Button
    android:id="@+id/send"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignTop="@id/open"
    android:layout_toLeftOf="@id/open"
    android:text="Send" />

<Button
    android:id="@+id/close"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignTop="@id/send"
    android:layout_toLeftOf="@id/send"
    android:text="Close" />

<强>的AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.bluetoothprinter"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="15" />

<supports-screens android:anyDensity="true" />

<uses-permission android:name="android.permission.BLUETOOTH" />

<application
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".MainActivity"
        android:label="@string/title_activity_main" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

结果图片如下：

将数据发送到蓝牙打印机

1 个答案: