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「.NET 開発基盤部会 Wiki」は、「Open棟梁Project」,「OSSコンソーシアム .NET開発基盤部会」によって運営されています。
Flutter の step by step（其の二）。
import 'dart:async';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
...
class _MyHomePageState extends State<MyHomePage> {
static const platform = const MethodChannel('samples.flutter.dev/battery');
// Get battery level.
String _batteryLevel = 'Unknown battery level.';
Future<void> _getBatteryLevel() async {
String batteryLevel;
try {
final int result = await platform.invokeMethod('getBatteryLevel');
batteryLevel = 'Battery level at $result % .';
} on PlatformException catch (e) {
batteryLevel = "Failed to get battery level: '${e.message}'.";
}
setState(() {
_batteryLevel = batteryLevel;
});
}
Widget build(BuildContext context) {
...
ElevatedButton(
child: const Text('BatteryLevel Button'),
style: ElevatedButton.styleFrom(
primary: Colors.orange,
onPrimary: Colors.white,
),
onPressed: _getBatteryLevel,
)
...
}
package com.opentouryo.flutter_template
import androidx.annotation.NonNull
import io.flutter.embedding.android.FlutterActivity
import io.flutter.embedding.engine.FlutterEngine
import io.flutter.plugin.common.MethodChannel
import android.content.Context
import android.content.ContextWrapper
import android.content.Intent
import android.content.IntentFilter
import android.os.BatteryManager
import android.os.Build.VERSION
import android.os.Build.VERSION_CODES
class MainActivity: FlutterActivity() {
private val CHANNEL = "samples.flutter.dev/battery"
override fun configureFlutterEngine(@NonNull flutterEngine: FlutterEngine) {
super.configureFlutterEngine(flutterEngine)
MethodChannel(flutterEngine.dartExecutor.binaryMessenger, CHANNEL).setMethodCallHandler {
call, result ->
// Note: this method is invoked on the main thread.
// TODO
if (call.method == "getBatteryLevel") {
val batteryLevel = getBatteryLevel()
if (batteryLevel != -1) {
result.success(batteryLevel)
} else {
result.error("UNAVAILABLE", "Battery level not available.", null)
}
} else {
result.notImplemented()
}
}
}
private fun getBatteryLevel(): Int {
val batteryLevel: Int
if (VERSION.SDK_INT >= VERSION_CODES.LOLLIPOP) {
val batteryManager = getSystemService(Context.BATTERY_SERVICE) as BatteryManager
batteryLevel = batteryManager.getIntProperty(BatteryManager.BATTERY_PROPERTY_CAPACITY)
} else {
val intent = ContextWrapper(applicationContext).registerReceiver(null, IntentFilter(Intent.ACTION_BATTERY_CHANGED))
batteryLevel = intent!!.getIntExtra(BatteryManager.EXTRA_LEVEL, -1) * 100 / intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1)
}
return batteryLevel
}
}
@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
override func application(
_ application: UIApplication,
didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
let controller : FlutterViewController = window?.rootViewController as! FlutterViewController
let batteryChannel = FlutterMethodChannel(name: "samples.flutter.dev/battery",
binaryMessenger: controller.binaryMessenger)
batteryChannel.setMethodCallHandler({
(call: FlutterMethodCall, result: @escaping FlutterResult) -> Void in
// Note: this method is invoked on the UI thread.
// Handle battery messages.
guard call.method == "getBatteryLevel" else {
result(FlutterMethodNotImplemented)
return
}
self?.receiveBatteryLevel(result: result)
})
GeneratedPluginRegistrant.register(with: self)
return super.application(application, didFinishLaunchingWithOptions: launchOptions)
}
}
private func receiveBatteryLevel(result: FlutterResult) {
let device = UIDevice.current
device.isBatteryMonitoringEnabled = true
if device.batteryState == UIDevice.BatteryState.unknown {
result(FlutterError(code: "UNAVAILABLE",
message: "Battery info unavailable",
details: nil))
} else {
result(Int(device.batteryLevel * 100))
}
}
<!-- Deep Links --> <intent-filter> <action android:name="android.intent.action.VIEW" /> <category android:name="android.intent.category.DEFAULT" /> <category android:name="android.intent.category.BROWSABLE" /> <data android:scheme="app" android:host="app_a" /> </intent-filter>
<!-- App Links --> <intent-filter android:autoVerify="true"> <action android:name="android.intent.action.VIEW" /> <category android:name="android.intent.category.DEFAULT" /> <category android:name="android.intent.category.BROWSABLE" /> <data android:scheme="http" android:host="example.com" /> </intent-filter>
ロケーション・バー直では、動かないとのこと。
以下のHTMLを作成し、ソコから飛んでみる。
<!DOCTYPE html>
<html>
<body>
<a href="app://app_a/">App Aに飛ぶ</a>
</body>
</html><!DOCTYPE html>
<html>
<body>
<a href="http://example.com/">App Aに飛ぶ</a>
</body>
</html>古い情報だと、プラットフォーム固有のカスタムコードで、
プラットフォームのAppAuth?を使っているが、最近は、flutter_appauthが利用できる。
HTTPパッケージを追加する必要がある。
import 'package:http/http.dart';
void sendRequest() {
http
.get(url)
.then((response) {
print(response);
})
.catchError((error) => print(error));
}Future<void> sendRequest() async {
try {
final response = await http.get(url);
print(response);
} on Exception caach (error) {
print(error);
}
}...
var response = await http.post(
"https://www.example.com/path/to/api",
body: {
"nickname": "chooyan",
"description": "A freelance mobile app developer",
},
);
