Flutter标签打印机插件niimbot_label_printer的使用
Flutter标签打印机插件niimbot_label_printer的使用
NiimbotLabelPrinter 是一个用于在 Flutter 应用程序中使用 Niimbot 标签打印机的包。该包提供了简单的接口来通过蓝牙连接到 Niimbot 打印机，管理连接，并发送打印数据。
特性
- 请求蓝牙权限。
- 检查蓝牙是否已启用。
- 连接到和断开 Niimbot 打印机的连接。
- 获取配对的蓝牙设备。
- 向打印机发送打印数据。
安装
在 pubspec.yaml 文件中添加 niimbot_label_printer 依赖：
dependencies:
niimbot_label_printer: ^0.0.1
使用
要使用 NiimbotLabelPrinter 插件，请遵循以下步骤：
- 请求蓝牙权限：
final bool result = await NiimbotLabelPrinter.requestPermissionGrant();
- 检查蓝牙是否已启用：
final bool result = await NiimbotLabelPrinter.bluetoothIsEnabled();
- 连接到 Niimbot 打印机：
final bool result = await NiimbotLabelPrinter.connect(device);
- 断开连接：
final bool result = await NiimbotLabelPrinter.disconnect();
- 获取配对的蓝牙设备：
final List<BluetoothDevice> devices = await NiimbotLabelPrinter.getPairedDevices();
- 发送打印数据到打印机：
final bool result = await NiimbotLabelPrinter.send(printData);
- 断开连接：
final bool result = await NiimbotLabelPrinter.disconnect();
示例代码
以下是完整的示例代码，展示了如何使用 NiimbotLabelPrinter 插件：
import 'dart:async';
import 'dart:ui' as ui;
import 'dart:ui';
import 'package:flutter/rendering.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:niimbot_label_printer/niimbot_label_printer.dart';
import 'package:niimbot_label_printer_example/custom_canvas_widget.dart';
void main() {
runApp(const Apps());
}
class Apps extends StatelessWidget {
const Apps({super.key});
[@override](/user/override)
Widget build(BuildContext context) {
return const MaterialApp(
home: MyApp(),
);
}
}
class MyApp extends StatefulWidget {
const MyApp({super.key});
[@override](/user/override)
State<MyApp> createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
final TextEditingController txttext = TextEditingController();
final TextEditingController txtwidth = TextEditingController(text: '50');
final TextEditingController txtheight = TextEditingController(text: '30');
final TextEditingController txtpixelformm = TextEditingController(text: '8');
bool rotate = false;
bool invertColor = false;
int density = 3; //1 and 5
int labelType = 1; // 1 and 3
String _msj = 'Unknown';
final NiimbotLabelPrinter _niimbotLabelPrinterPlugin = NiimbotLabelPrinter();
List<BluetoothDevice> _devices = [];
String macConnection = '';
bool connecting = false;
bool customImage = true;
final globalKey = GlobalKey();
List<TextInfo> texts = [];
ui.Image? _image;
double _width = 400;
double _height = 240;
[@override](/user/override)
void initState() {
super.initState();
}
[@override](/user/override)
void dispose() {
txtwidth.dispose();
txtheight.dispose();
txtpixelformm.dispose();
super.dispose();
}
[@override](/user/override)
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Status: $_msj'),
actions: [
PopupMenuButton<String>(
onSelected: (String value) async {
switch (value) {
case "permission_is_granted":
final bool result = await _niimbotLabelPrinterPlugin.requestPermissionGrant();
setState(() {
_msj = result ? 'Permission is granted' : 'Permission is not granted';
});
break;
case "bluetooth_is_enabled":
final bool result = await _niimbotLabelPrinterPlugin.bluetoothIsEnabled();
setState(() {
_msj = result ? 'Bluetooth is enabled' : 'Bluetooth is not enabled';
});
break;
case "is_connected":
final bool result = await _niimbotLabelPrinterPlugin.isConnected();
setState(() {
_msj = result ? 'Bluetooth is connected' : 'Bluetooth is not connected';
});
break;
case "get_paired_devices":
final List<BluetoothDevice> result = await _niimbotLabelPrinterPlugin.getPairedDevices();
_devices = result;
setState(() {
_msj = "Devices ${result.length}";
});
break;
case "disconnect":
final bool result = await _niimbotLabelPrinterPlugin.disconnect();
setState(() {
_msj = result ? 'Disconnected' : 'Not disconnected';
});
break;
}
},
itemBuilder: (BuildContext context) =>
<PopupMenuEntry<String>>[
const PopupMenuItem<String>(
value: "permission_is_granted",
child: Text("Permission is granted"),
),
const PopupMenuItem<String>(
value: "bluetooth_is_enabled",
child: Text("Bluetooth is enabled"),
),
const PopupMenuItem<String>(
value: "is_connected",
child: Text("Is connected"),
),
const PopupMenuItem<String>(
value: "get_paired_devices",
child: Text("Get paired devices"),
),
const PopupMenuItem<String>(
value: "disconnect",
child: Text("Disconnect"),
),
],
)
],
),
body: Padding(
padding: const EdgeInsets.all(8.0),
child: SingleChildScrollView(
child: Column(
children: [
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
TextButton(
onPressed: () async {
modalCustomImage(context);
},
child: const Text('Toggle custom image'),
),
TextButton(
onPressed: () async {
_image = await loadImage("assets/2.png");
setState(() {});
},
child: const Text('Toggle image assets'),
),
],
),
_image != null
? Column(
children: [
Container(
decoration: BoxDecoration(
border: Border.all(color: Colors.black, width: 1),
),
child: RawImage(image: _image!, width: _width, height: _height),
),
Text("image. width: ${_image!.width}, height: ${_image!.height}"),
],
)
: const SizedBox(),
Visibility(
visible: _image != null,
child: Column(
children: [
Slider(
max: 3,
min: 1,
divisions: 2,
label: "Label type: ${labelType.toInt()}",
value: labelType.toDouble(),
onChanged: (value) {
setState(() {
labelType = value.toInt();
});
},
),
Slider(
max: 5,
min: 1,
divisions: 4,
label: "Density: ${density.toInt()}",
value: density.toDouble(),
onChanged: (value) {
setState(() {
density = value.toInt();
});
},
),
Row(
children: [
SizedBox(
width: 200,
child: CheckboxListTile(
value: rotate,
controlAffinity: ListTileControlAffinity.leading,
onChanged: (value) {
setState(() {
rotate = value!;
setState(() {});
});
},
title: const Text('Rotated'),
),
),
ElevatedButton(
onPressed: () async {
final bool isConnected = await _niimbotLabelPrinterPlugin.isConnected();
if (!isConnected) {
setState(() {
_msj = 'Not connected';
});
return;
}
ui.Image image = _image!;
ByteData? byteData = await image.toByteData();
List<int> bytesImage = byteData!.buffer.asUint8List().toList();
Map<String, dynamic> datosImagen = {
"bytes": bytesImage,
"width": image.width,
"height": image.height,
"rotate": rotate,
"invertColor": invertColor,
"density": density,
"labelType": labelType,
};
PrintData printData = PrintData.fromMap(datosImagen);
final bool result = await _niimbotLabelPrinterPlugin.send(printData);
setState(() {
_msj = result ? 'Printed' : 'Not printed';
});
},
style: ElevatedButton.styleFrom(backgroundColor: Colors.green, shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(10))),
child: const Text('Print image', style: TextStyle(color: Colors.white)),
),
],
),
],
),
),
SizedBox(
height: 200,
child: ListView.builder(
shrinkWrap: true,
itemCount: _devices.length,
itemBuilder: (BuildContext context, int index) {
BluetoothDevice device = _devices[index];
return ListTile(
selected: device.address == macConnection,
title: Text(device.name),
subtitle: Text(device.address),
leading: Visibility(
visible: connecting && device.address == macConnection,
child: const CircularProgressIndicator(strokeWidth: 1),
),
onTap: () async {
setState(() {
connecting = true;
macConnection = device.address;
});
bool result = await _niimbotLabelPrinterPlugin.connect(device);
setState(() {
_msj = result ? 'Connected' : 'Not connected';
macConnection = device.address;
connecting = false;
});
},
);
},
),
),
],
),
),
),
);
}
void modalCustomImage(BuildContext context) async {
double textSize = 10;
bool isBold = false;
bool isCenter = false;
await showDialog(
context: context,
builder: (BuildContext context) {
return BackdropFilter(
filter: ImageFilter.blur(sigmaX: 10, sigmaY: 10),
child: AlertDialog(
shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(6)),
content: StatefulBuilder(
builder: (BuildContext context, StateSetter setState) {
return SizedBox(
width: MediaQuery.of(context).size.width,
child: SingleChildScrollView(
child: Column(
mainAxisSize: MainAxisSize.min,
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
const Text("Donate in PayPal", textAlign: TextAlign.center, style: TextStyle(fontSize: 20, color: Colors.black)),
IconButton(
onPressed: () {
Navigator.pop(context);
},
icon: const Icon(Icons.close),
),
],
),
CustomQRWidget(
textList: texts,
qrData: "www.example.com",
width: _width,
height: _height,
),
TextButton(
onPressed: () {
setState(() {
texts.clear();
txttext.clear();
});
},
child: const Text("Clear all"),
),
Row(
children: [
Expanded(
child: TextField(
controller: txttext,
decoration: const InputDecoration(labelText: 'Text'),
),
),
TextButton(
onPressed: () {
setState(() {
texts.add(
TextInfo(
text: txttext.text,
fontSize: textSize,
position: isCenter ? TextPosition.center : TextPosition.left,
isBold: isBold,
),
);
txttext.clear();
});
},
child: const Text("Add text"),
),
],
),
Text("fontSize: ${textSize.toInt()}"),
Slider(
value: textSize,
min: 10,
max: 90,
onChanged: (value) {
setState(() {
textSize = value;
});
},
),
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
SizedBox(
width: 140,
child: CheckboxListTile(
value: isBold,
dense: true,
controlAffinity: ListTileControlAffinity.leading,
onChanged: (value) {
setState(() {
isBold = value!;
setState(() {});
});
},
title: const Text('Bold'),
),
),
SizedBox(
width: 140,
child: CheckboxListTile(
value: isCenter,
dense: true,
controlAffinity: ListTileControlAffinity.leading,
onChanged: (value) {
setState(() {
isCenter = value!;
setState(() {});
});
},
title: const Text('Center'),
),
),
],
),
Container(
padding: const EdgeInsets.all(5),
decoration: BoxDecoration(
border: Border.all(color: Colors.grey, width: 1),
borderRadius: BorderRadius.circular(4),
),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
const Text("Size label to print", style: TextStyle(fontSize: 8)),
const Text("The image can be created with a specific size and rotated before printing.", style: TextStyle(fontSize: 8)),
Row(
children: [
SizedBox(
width: 100,
child: TextField(
controller: txtwidth,
decoration: const InputDecoration(labelText: 'Width mm'),
),
),
SizedBox(
width: 100,
child: TextField(
controller: txtheight,
decoration: const InputDecoration(labelText: 'Height mm'),
),
),
],
),
SizedBox(
width: 200,
child: TextField(
controller: txtpixelformm,
decoration: const InputDecoration(labelText: 'Pixels per mm'),
),
),
ElevatedButton(
onPressed: () async {
updateSize();
_image = await CustomQRWidget.getImage(
textList: texts,
qrData: "www.example.com",
width: _width,
height: _height,
);
if (context.mounted) Navigator.pop(context);
},
style: ElevatedButton.styleFrom(backgroundColor: Colors.green, shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(10))),
child: const Text('Create image', style: TextStyle(color: Colors.white)),
),
],
),
),
],
),
),
);
},
),
),
);
},
);
setState(() {});
}
void updateSize() {
int? width = int.tryParse(txtwidth.text);
int? height = int.tryParse(txtheight.text);
int? pixels = int.tryParse(txtpixelformm.text);
if (width != null && height != null && pixels != null) {
_width = width * pixels.toDouble();
_height = height * pixels.toDouble();
setState(() {});
}
}
Future<ui.Image> resizeImage(ui.Image image, double targetWidth, double targetHeight) async {
final recorder = ui.PictureRecorder();
final canvas = Canvas(recorder);
// Scale the image
final paint = Paint();
final scaleX = targetWidth / image.width;
final scaleY = targetHeight / image.height;
canvas.scale(scaleX, scaleY);
canvas.drawImage(image, Offset.zero, paint);
final resizedImage = await recorder.endRecording().toImage(
targetWidth.toInt(),
targetHeight.toInt(),
);
return resizedImage;
}
Future<ui.Image> loadImage(String asset) async {
final ByteData data = await rootBundle.load(asset);
final Uint8List bytes = data.buffer.asUint8List();
final Completer<ui.Image> completer = Completer();
ui.decodeImageFromList(bytes, (ui.Image img) {
//print("Image loaded, size: ${img.width}x${img.height}");
completer.complete(img);
});
return completer.future;
}
}
更多关于Flutter标签打印机插件niimbot_label_printer的使用的实战教程也可以访问 https://www.itying.com/category-92-b0.html
