Flutter蓝牙热敏打印机插件rt_bluetooth_thermal_printer的使用
Flutter蓝牙热敏打印机插件rt_bluetooth_thermal_printer的使用
简介
rt_bluetooth_thermal_printer 是一个用于通过蓝牙打印收据的 Flutter 插件（仅支持 Android）。它支持 58mm 和 80mm 的蓝牙打印机。
该插件不依赖位置权限，因此遵循 Google 对 Android 10 的政策。
添加依赖项
在 pubspec.yaml 文件中添加以下依赖项：
dependencies:
rt_bluetooth_thermal_printer: ^最新版本号
esc_pos_utils: ^最新版本号
使用示例
示例代码
以下是完整的示例代码，展示如何使用 rt_bluetooth_thermal_printer 插件进行蓝牙热敏打印机的连接和打印。
main.dart
import 'dart:async';
import 'package:rt_bluetooth_thermal_printer/bluetooth_thermal_printer.dart';
import 'package:esc_pos_utils/esc_pos_utils.dart';
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatefulWidget {
[@override](/user/override)
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
[@override](/user/override)
void initState() {
super.initState();
}
bool connected = false;
List availableBluetoothDevices = [];
Future<void> getBluetooth() async {
final List bluetooths = await BluetoothThermalPrinter.getBluetooths;
print("Print $bluetooths");
setState(() {
availableBluetoothDevices = bluetooths;
});
}
Future<void> setConnect(String mac) async {
final String result = await BluetoothThermalPrinter.connect(mac);
print("state connected $result");
if (result == "true") {
setState(() {
connected = true;
});
}
}
Future<void> printTicket() async {
String isConnected = await BluetoothThermalPrinter.connectionStatus;
if (isConnected == "true") {
List<int> bytes = await getTicket();
final result = await BluetoothThermalPrinter.writeBytes(bytes);
print("Print $result");
} else {
// Handle Not Connected Scenario
}
}
Future<void> printGraphics() async {
String isConnected = await BluetoothThermalPrinter.connectionStatus;
if (isConnected == "true") {
List<int> bytes = await getGraphicsTicket();
final result = await BluetoothThermalPrinter.writeBytes(bytes);
print("Print $result");
} else {
// Handle Not Connected Scenario
}
}
Future<List<int>> getGraphicsTicket() async {
List<int> bytes = [];
CapabilityProfile profile = await CapabilityProfile.load();
final generator = Generator(PaperSize.mm80, profile);
// Print QR Code using native function
bytes += generator.qrcode('example.com');
bytes += generator.hr();
// Print Barcode using native function
final List<int> barData = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 4];
bytes += generator.barcode(Barcode.upcA(barData));
bytes += generator.cut();
return bytes;
}
Future<List<int>> getTicket() async {
List<int> bytes = [];
CapabilityProfile profile = await CapabilityProfile.load();
final generator = Generator(PaperSize.mm80, profile);
bytes += generator.text("Demo Shop",
styles: PosStyles(
align: PosAlign.center,
height: PosTextSize.size2,
width: PosTextSize.size2,
),
linesAfter: 1);
bytes += generator.text(
"18th Main Road, 2nd Phase, J. P. Nagar, Bengaluru, Karnataka 560078",
styles: PosStyles(align: PosAlign.center));
bytes += generator.text('Tel: +919591708470',
styles: PosStyles(align: PosAlign.center));
bytes += generator.hr();
bytes += generator.row([
PosColumn(
text: 'No',
width: 1,
styles: PosStyles(align: PosAlign.left, bold: true)),
PosColumn(
text: 'Item',
width: 5,
styles: PosStyles(align: PosAlign.left, bold: true)),
PosColumn(
text: 'Price',
width: 2,
styles: PosStyles(align: PosAlign.center, bold: true)),
PosColumn(
text: 'Qty',
width: 2,
styles: PosStyles(align: PosAlign.center, bold: true)),
PosColumn(
text: 'Total',
width: 2,
styles: PosStyles(align: PosAlign.right, bold: true)),
]);
bytes += generator.row([
PosColumn(text: "1", width: 1),
PosColumn(
text: "Tea",
width: 5,
styles: PosStyles(
align: PosAlign.left,
)),
PosColumn(
text: "10",
width: 2,
styles: PosStyles(
align: PosAlign.center,
)),
PosColumn(text: "1", width: 2, styles: PosStyles(align: PosAlign.center)),
PosColumn(text: "10", width: 2, styles: PosStyles(align: PosAlign.right)),
]);
bytes += generator.row([
PosColumn(text: "2", width: 1),
PosColumn(
text: "Sada Dosa",
width: 5,
styles: PosStyles(
align: PosAlign.left,
)),
PosColumn(
text: "30",
width: 2,
styles: PosStyles(
align: PosAlign.center,
)),
PosColumn(text: "1", width: 2, styles: PosStyles(align: PosAlign.center)),
PosColumn(text: "30", width: 2, styles: PosStyles(align: PosAlign.right)),
]);
bytes += generator.row([
PosColumn(text: "3", width: 1),
PosColumn(
text: "Masala Dosa",
width: 5,
styles: PosStyles(
align: PosAlign.left,
)),
PosColumn(
text: "50",
width: 2,
styles: PosStyles(
align: PosAlign.center,
)),
PosColumn(text: "1", width: 2, styles: PosStyles(align: PosAlign.center)),
PosColumn(text: "50", width: 2, styles: PosStyles(align: PosAlign.right)),
]);
bytes += generator.row([
PosColumn(text: "4", width: 1),
PosColumn(
text: "Rova Dosa",
width: 5,
styles: PosStyles(
align: PosAlign.left,
)),
PosColumn(
text: "70",
width: 2,
styles: PosStyles(
align: PosAlign.center,
)),
PosColumn(text: "1", width: 2, styles: PosStyles(align: PosAlign.center)),
PosColumn(text: "70", width: 2, styles: PosStyles(align: PosAlign.right)),
]);
bytes += generator.hr();
bytes += generator.row([
PosColumn(
text: 'TOTAL',
width: 6,
styles: PosStyles(
align: PosAlign.left,
height: PosTextSize.size4,
width: PosTextSize.size4,
)),
PosColumn(
text: "160",
width: 6,
styles: PosStyles(
align: PosAlign.right,
height: PosTextSize.size4,
width: PosTextSize.size4,
)),
]);
bytes += generator.hr(ch: '=', linesAfter: 1);
// ticket.feed(2);
bytes += generator.text('Thank you!',
styles: PosStyles(align: PosAlign.center, bold: true));
bytes += generator.text("26-11-2020 15:22:45",
styles: PosStyles(align: PosAlign.center), linesAfter: 1);
bytes += generator.text(
'Note: Goods once sold will not be taken back or exchanged.',
styles: PosStyles(align: PosAlign.center, bold: false));
bytes += generator.cut();
return bytes;
}
[@override](/user/override)
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(
title: const Text('Bluetooth Thermal Printer Demo'),
),
body: Container(
padding: EdgeInsets.all(20),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text("Search Paired Bluetooth"),
TextButton(
onPressed: () {
this.getBluetooth();
},
child: Text("Search"),
),
Container(
height: 200,
child: ListView.builder(
itemCount: availableBluetoothDevices.length > 0
? availableBluetoothDevices.length
: 0,
itemBuilder: (context, index) {
return ListTile(
onTap: () {
String select = availableBluetoothDevices[index];
List list = select.split("#");
// String name = list[0];
String mac = list[1];
this.setConnect(mac);
},
title: Text('${availableBluetoothDevices[index]}'),
subtitle: Text("Click to connect"),
);
},
),
),
SizedBox(
height: 30,
),
TextButton(
onPressed: connected ? this.printGraphics : null,
child: Text("Print"),
),
TextButton(
onPressed: connected ? this.printTicket : null,
child: Text("Print Ticket"),
),
],
),
),
),
);
}
}
更多关于Flutter蓝牙热敏打印机插件rt_bluetooth_thermal_printer的使用的实战教程也可以访问 https://www.itying.com/category-92-b0.html
1 回复
更多关于Flutter蓝牙热敏打印机插件rt_bluetooth_thermal_printer的使用的实战系列教程也可以访问 https://www.itying.com/category-92-b0.html
rt_bluetooth_thermal_printer 是一个用于 Flutter 的插件，它允许你通过蓝牙连接热敏打印机并发送打印任务。以下是如何使用这个插件的基本步骤：
1. 添加依赖
首先，你需要在 pubspec.yaml 文件中添加 rt_bluetooth_thermal_printer 插件的依赖：
dependencies:
flutter:
sdk: flutter
rt_bluetooth_thermal_printer: ^1.0.0 # 请使用最新版本
然后运行 flutter pub get 来获取依赖。
2. 导入插件
在你的 Dart 文件中导入插件：
import 'package:rt_bluetooth_thermal_printer/rt_bluetooth_thermal_printer.dart';
3. 初始化插件
在使用插件之前，你需要初始化它：
void initPrinter() async {
bool isInitialized = await RtBluetoothThermalPrinter.init();
if (isInitialized) {
print("Printer initialized successfully");
} else {
print("Failed to initialize printer");
}
}
4. 扫描并连接蓝牙设备
你可以使用 scan 方法来扫描附近的蓝牙设备，并使用 connect 方法来连接打印机：
void scanAndConnect() async {
List<BluetoothDevice> devices = await RtBluetoothThermalPrinter.scan();
if (devices.isNotEmpty) {
BluetoothDevice printer = devices.first; // 选择第一个设备
bool isConnected = await RtBluetoothThermalPrinter.connect(printer);
if (isConnected) {
print("Connected to printer: ${printer.name}");
} else {
print("Failed to connect to printer");
}
} else {
print("No devices found");
}
}
5. 打印文本
连接成功后，你可以使用 printText 方法来打印文本：
void printText() async {
String text = "Hello, World!";
bool isPrinted = await RtBluetoothThermalPrinter.printText(text);
if (isPrinted) {
print("Text printed successfully");
} else {
print("Failed to print text");
}
}
6. 打印自定义内容
你还可以使用 printCustom 方法来打印自定义内容，比如图片、条形码等：
void printCustom() async {
String customContent = "Custom content to print";
bool isPrinted = await RtBluetoothThermalPrinter.printCustom(customContent);
if (isPrinted) {
print("Custom content printed successfully");
} else {
print("Failed to print custom content");
}
}
7. 断开连接
打印完成后，记得断开与打印机的连接：
void disconnectPrinter() async {
bool isDisconnected = await RtBluetoothThermalPrinter.disconnect();
if (isDisconnected) {
print("Printer disconnected successfully");
} else {
print("Failed to disconnect printer");
}
}
8. 处理权限
在 Android 上，你需要确保应用具有蓝牙和位置权限。你可以在 AndroidManifest.xml 中添加以下权限：
<uses-permission android:name="android.permission.BLUETOOTH"/>
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
并在运行时请求这些权限。
9. 处理错误
在实际使用中，你可能会遇到各种错误，比如连接失败、打印失败等。确保你正确处理这些错误，并提供适当的用户反馈。
10. 示例代码
以下是一个完整的示例代码，展示了如何使用 rt_bluetooth_thermal_printer 插件：
import 'package:flutter/material.dart';
import 'package:rt_bluetooth_thermal_printer/rt_bluetooth_thermal_printer.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
[@override](/user/override)
Widget build(BuildContext context) {
return MaterialApp(
home: PrinterScreen(),
);
}
}
class PrinterScreen extends StatefulWidget {
[@override](/user/override)
_PrinterScreenState createState() => _PrinterScreenState();
}
class _PrinterScreenState extends State<PrinterScreen> {
[@override](/user/override)
void initState() {
super.initState();
initPrinter();
}
void initPrinter() async {
bool isInitialized = await RtBluetoothThermalPrinter.init();
if (isInitialized) {
print("Printer initialized successfully");
} else {
print("Failed to initialize printer");
}
}
void scanAndConnect() async {
List<BluetoothDevice> devices = await RtBluetoothThermalPrinter.scan();
if (devices.isNotEmpty) {
BluetoothDevice printer = devices.first; // 选择第一个设备
bool isConnected = await RtBluetoothThermalPrinter.connect(printer);
if (isConnected) {
print("Connected to printer: ${printer.name}");
} else {
print("Failed to connect to printer");
}
} else {
print("No devices found");
}
}
void printText() async {
String text = "Hello, World!";
bool isPrinted = await RtBluetoothThermalPrinter.printText(text);
if (isPrinted) {
print("Text printed successfully");
} else {
print("Failed to print text");
}
}
void disconnectPrinter() async {
bool isDisconnected = await RtBluetoothThermalPrinter.disconnect();
if (isDisconnected) {
print("Printer disconnected successfully");
} else {
print("Failed to disconnect printer");
}
}
[@override](/user/override)
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("Bluetooth Thermal Printer"),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
ElevatedButton(
onPressed: scanAndConnect,
child: Text("Scan and Connect"),
),
ElevatedButton(
onPressed: printText,
child: Text("Print Text"),
),
ElevatedButton(
onPressed: disconnectPrinter,
child: Text("Disconnect Printer"),
),
],
),
),
);
}
}