Android 原生项目集成 Flutter

要在Android原生项目中集成Flutter，你需要按照以下步骤操作：

1. 将Flutter模块添加到现有的Android项目中。
2. 配置Gradle脚本以构建和嵌入Flutter模块。
3. 初始化并运行Flutter引擎。
4. 创建Flutter的活动和视图。

以下是一个简化的示例代码，展示了如何在Android项目中集成Flutter：

import io.flutter.embedding.android.FlutterView;
import io.flutter.embedding.engine.FlutterEngine;
import io.flutter.plugin.common.PluginRegistry;
 
public class MainActivity extends AppCompatActivity implements PluginRegistry.PluginRegistrantCallback {
    private FlutterEngine flutterEngine;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 
        // 初始化Flutter引擎
        flutterEngine = new FlutterEngine(this);
        flutterEngine.getDartExecutor().executeDartEntrypoint(
                DartExecutor.DartEntrypoint.createDefault()
        );
        flutterEngine.getPlugins().add(new io.flutter.plugins.flutter_plugin.FlutterPlugin());
        
        // 创建Flutter视图并附加到Activity
        FlutterView flutterView = new FlutterView(this);
        setContentView(flutterView);
 
        // 将Flutter引擎附加到Flutter视图
        flutterView.setFlutterEngine(flutterEngine);
    }
 
    @Override
    public void onStart() {
        super.onStart();
        if (flutterEngine != null) {
            flutterEngine.getLifecycleChannel().appIsInForeground(true);
        }
    }
 
    @Override
    public void onStop() {
        super.onStop();
        if (flutterEngine != null) {
            flutterEngine.getLifecycleChannel().appIsInForeground(false);
        }
    }
 
    @Override
    public void registerWith(PluginRegistry registry) {
        // 注册所需的Flutter插件
        GeneratedPluginRegistrant.registerWith(this);
    }
}

在AndroidManifest.xml中添加所需的权限和Flutter相关的Activity配置：

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.myapp">
 
    <!-- 添加FlutterActivity配置 -->
    <application
        ...>
        ...
        <activity
            android:name="io.flutter.embedding.android.FlutterActivity"
            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
            android:hardwareAccelerated="true"
            android:windowSoftInputMode="adjustResize">
            <!-- 添加用于指示Flutter将其用作主入口点的intent过滤器 -->
            <intent-filter>