如何在android中通过蓝牙连接手机和打印机？

How to connect a mobile and a printer via bluetooth in android?

提问by prabu

Can anyone tell me how to connect a mobileand a printervia bluetoothto print a text file in android?

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？

That is,if i click the print button from the android application,the printer has to print that corresponding file.As per my knowledge i have searched for it in Google, but i couldn't find any good samples to do it.Has anyone have at-least one sample android program to do this, it will be better to clear my chaos.

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，我已经在谷歌中搜索过它，但我找不到任何好的样本来做到这一点。有没有人至少有一个示例 android 程序来执行此操作，最好清除我的混乱。

Suggestions please. Thanks for your precious time!..

请提出建议。感谢您的宝贵时间！...

采纳答案by Naveed Ahmad

Bluetooth Printer Android Example Create a new android project BlueToothPrinterApp in your editor.

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。

Step 1:

第1步：

Create main activity like below

创建如下主要活动

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();
}
}
}

Step 2:

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(“8ce255c0-200a-11e0-ac64-0800200c9a66″);
// 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;
}
}

Step 3:

第 3 步：

Edit your main.xml file and paste below code.

编辑您的 main.xml 文件并粘贴以下代码。

res/layout/main.xml

res/layout/main.xml

<?xml version=”1.0″ encoding=”utf-8″?>
<RelativeLayout xmlns:android=”http://schemas.android.com/apk/res/android&#8221;
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>

Step 4:

第四步：

Now edit your AndroidManifest.xml

现在编辑你的 AndroidManifest.xml

Add bluetooth permission and admin permission.

添加蓝牙权限和管理员权限。

AndroidManifest.xml

AndroidManifest.xml

<?xml version=”1.0″ encoding=”utf-8″?>
<manifest xmlns:android=”http://schemas.android.com/apk/res/android&#8221;
package=”com.example.BlueToothPrinterApp”
android:versionCode=”1″
android:versionName=”1.0″>
<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>
<uses-sdk android:minSdkVersion=”14″ />
<uses-permission android:name=”android.permission.BLUETOOTH”></uses-permission>
<uses-permission android:name=”android.permission.BLUETOOTH_ADMIN”></uses-permission>
</manifest>

Compile and run this application. Enter message and press print button.

编译并运行此应用程序。输入消息并按打印按钮。

You will see list of bluetooth devices. Select bluettoth printer.

您将看到蓝牙设备列表。选择蓝牙打印机。

Check print on your bluetooth printer.

检查您的蓝牙打印机上的打印。

here is the CODE Reference...

这是代码参考...

回答by Mazen Rashed

You can use this awesome lib, you can connect to any printer and print easily,

你可以使用这个很棒的库，你可以连接到任何打印机并轻松打印，

https://github.com/mazenrashed/Printooth

https://github.com/mazenrasshed/Printooth

you can download it by:

您可以通过以下方式下载：

implementation 'com.github.mazenrashed:Printooth:${LAST_VERSION}'

and use it like:

并使用它：

var printables = ArrayList<Printable>()
var printable = Printable.PrintableBuilder()  
.setText("Hello World")

printables.add(printable)

BluetoothPrinter.printer().print(printables)