flutter打开android界面,Flutter 插件(调用原生方法--Android)
时间: 2023-08-21 12:02:36 浏览: 67
要在Flutter中调用Android原生方法,可以使用Flutter插件。Flutter插件是一个将Flutter应用程序与原生平台通信的桥梁。下面是一些步骤来创建一个Flutter插件并在其中调用Android原生方法:
1. 使用Flutter插件模板创建一个Flutter插件:
```
flutter create --template=plugin <plugin-name>
```
2. 在Flutter插件项目的`android`目录下,打开`build.gradle`文件,并添加以下代码:
```
dependencies {
implementation 'io.flutter:flutter_embedding_v2.7.0'
// 其他依赖项
}
```
3. 在Flutter插件项目的`android/src/main`目录下,创建一个`java`包,并在其中创建一个类,该类将包含您要调用的Android原生方法。例如,您可以创建一个名为`MyPlugin`的类,并在其中添加以下代码:
```
package com.example.my_plugin;
import android.content.Context;
import android.widget.Toast;
import io.flutter.embedding.engine.plugins.FlutterPlugin;
public class MyPlugin implements FlutterPlugin {
private Context context;
@Override
public void onAttachedToEngine(FlutterPluginBinding flutterPluginBinding) {
context = flutterPluginBinding.getApplicationContext();
}
@Override
public void onDetachedFromEngine(FlutterPluginBinding flutterPluginBinding) {
context = null;
}
public void showToast(String message) {
Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
}
}
```
4. 在Flutter插件项目的`lib`目录下,创建一个文件夹,并在其中创建一个`dart`文件,该文件将包含您要在Flutter中调用的方法。例如,您可以创建一个名为`my_plugin.dart`的文件,并在其中添加以下代码:
```
import 'package:flutter/services.dart';
class MyPlugin {
static const MethodChannel _channel =
const MethodChannel('my_plugin');
static Future<void> showToast(String message) async {
try {
await _channel.invokeMethod('showToast', {'message': message});
} on PlatformException catch (e) {
print(e.message);
}
}
}
```
5. 在Flutter插件项目的`android/src/main`目录下,创建一个`res`目录,并在其中创建一个`values`目录。在`values`目录中,创建一个`strings.xml`文件,并添加以下代码:
```
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_name">My Plugin</string>
</resources>
```
6. 在Flutter插件项目的`android/src/main`目录下,打开`AndroidManifest.xml`文件,并添加以下代码:
```
<application
android:name="io.flutter.app.FlutterApplication"
android:label="@string/app_name"
android:icon="@mipmap/ic_launcher">
<activity
android:name="io.flutter.embedding.android.FlutterActivity"
android:exported="true"
android:theme="@style/Theme.AppCompat.Light.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
</application>
```
7. 在Flutter插件项目的`android/src/main`目录下,打开`MyPlugin.java`文件,并添加以下代码:
```
package com.example.my_plugin;
import android.content.Context;
import android.widget.Toast;
import io.flutter.embedding.engine.plugins.FlutterPlugin;
import io.flutter.plugin.common.MethodCall;
import io.flutter.plugin.common.MethodChannel;
import io.flutter.plugin.common.PluginRegistry.Registrar;
public class MyPlugin implements FlutterPlugin {
private Context context;
private MethodChannel channel;
public static void registerWith(Registrar registrar) {
final MethodChannel channel = new MethodChannel(registrar.messenger(), "my_plugin");
channel.setMethodCallHandler(new MyPlugin(registrar.context(), channel));
}
private MyPlugin(Context context, MethodChannel channel) {
this.context = context;
this.channel = channel;
}
@Override
public void onAttachedToEngine(FlutterPluginBinding flutterPluginBinding) {
context = flutterPluginBinding.getApplicationContext();
channel = new MethodChannel(flutterPluginBinding.getBinaryMessenger(), "my_plugin");
channel.setMethodCallHandler(new MyPlugin(context, channel));
}
@Override
public void onDetachedFromEngine(FlutterPluginBinding flutterPluginBinding) {
context = null;
channel.setMethodCallHandler(null);
channel = null;
}
public void showToast(String message) {
Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
}
private void onMethodCall(MethodCall call, MethodChannel.Result result) {
if (call.method.equals("showToast")) {
String message = call.argument("message");
showToast(message);
result.success(null);
} else {
result.notImplemented();
}
}
}
```
8. 在Flutter应用程序中,导入您的Flutter插件,并使用以下代码调用Android原生方法:
```
import 'package:flutter/material.dart';
import 'package:my_plugin/my_plugin.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
body: Center(
child: ElevatedButton(
onPressed: () {
MyPlugin.showToast('Hello World!');
},
child: Text('Show Toast'),
),
),
),
);
}
}
```
这样,您就可以在Flutter应用程序中调用Android原生方法了!