Flutter中嵌入Android 原生TextView实例教程

public class TestTextView implements PlatformView r{
	
	private final TextView mTestTextView;
	
	/**
	 * 
	 * @param context
	 * @param messenger
	 * @param id
	 * @param params 初始化时 flutter 传递过来的参数
	 */
	TestTextView(Context context, BinaryMessenger messenger, int id, Map<String, Object> params) {
		//创建 TextView
		TextView lTextView = new TextView(context);
		lTextView.setText("Android的原生TextView");
		this.mTestTextView = lTextView;
		
		//flutter 传递过来的参数
		if (params!=null&&params.containsKey("content")) {
			String myContent = (String) params.get("content");
			lTextView.setText(myContent);
		}
	}
	
	@Override
	public View getView() {
		return mTestTextView;
	}
	
	@Override
	public void dispose() {
	
	}
	
}

import android.content.Context;
import java.util.Map;
import io.flutter.plugin.common.BinaryMessenger;
import io.flutter.plugin.common.StandardMessageCodec;
import io.flutter.plugin.platform.PlatformView;
import io.flutter.plugin.platform.PlatformViewFactory;

public class TestViewFactory extends PlatformViewFactory {
	private final BinaryMessenger messenger;
	public TestViewFactory(BinaryMessenger messenger) {
		super(StandardMessageCodec.INSTANCE);
		this.messenger = messenger;
	}
	
	/**
	 * 
	 * @param context
	 * @param id
	 * @param args args是由Flutter传过来的自定义参数
	 * @return
	 */
	@SuppressWarnings("unchecked")
	@Override
	public PlatformView create(Context context, int id, Object args) {
		//flutter 传递过来的参数
		Map<String, Object> params = (Map<String, Object>) args;
		//创建 TestTextView
		return new TestTextView(context, messenger, id, params);
		
	}

/**
 * flutter 调用 android 原生view
 *
 */
public class TestFluttertoAndroidTextViewPlugin {
	public static void registerWith(PluginRegistry registry) {
		//防止多次注册
		final String key = TestFluttertoAndroidTextViewPlugin.class.getCanonicalName();
		if (registry.hasPlugin(key)) return;
		//初始化 PluginRegistry
		PluginRegistry.Registrar registrar = registry.registrarFor(key);
		//设置标识
		registrar.platformViewRegistry().registerViewFactory("com.flutter_to_native_test_textview", new TestViewFactory(registrar.messenger()));
	}
}

import android.os.Bundle

import io.flutter.app.FlutterActivity
import io.flutter.plugins.FlutterToAndroidPlugins
import io.flutter.plugins.GeneratedPluginRegistrant

class MainActivity: FlutterActivity() {
 override fun onCreate(savedInstanceState: Bundle?) {
 super.onCreate(savedInstanceState)
 //flutter 项目工程中默认生成的 
 GeneratedPluginRegistrant.registerWith(this)
 //这是我们新创建的插件
 TestFluttertoAndroidTextViewPlugin.registerWith(this)
 
 }

 override fun onDestroy() {
 super.onDestroy()

 }
}

//这里设置的 viewType值与 android 中插件注册的标识 一至
//registrar.platformViewRegistry().registerViewFactory("com.flutter_to_native_test_textview", new TestViewFactory(registrar.messenger()));
mTextWidget = Container(
 height: 200,
 child: AndroidView(
 	//设置标识 
  viewType: "com.flutter_to_native_test_textview",
  ),
 );

@override
 Widget build(BuildContext context) {
 // TODO: implement build
 return Scaffold(
  appBar: appBar,
  //显示的页面
  body: mTextWidget,
 );
 }

   mTextWidget = Container(
   height: 200,
   child: AndroidView(
    //标识
    viewType: "com.flutter_to_native_test_textview",
    creationParams: {
    "content": "flutter 传入的文本内容",
    },
    //参数的编码方式
    creationParamsCodec: const StandardMessageCodec(),
   ),
   );

... ...	

TestTextView(Context context, BinaryMessenger messenger, int id, Map<String, Object> params) {
		... ..
		//flutter 传递过来的参数
		if (params!=null&&!params.isEmpty()&&params.containsKey("content")) {
			String myContent = (String) params.get("content");
			lTextView.setText(myContent);
		}

	... ...
	}

public class TestTextView implements PlatformView , MethodChannel.MethodCallHandler{
	
	private final TextView mTestTextView;
	
	TestTextView(Context context, BinaryMessenger messenger, int id, Map<String, Object> params) {
		
		... ...
		
		//com.flutter_to_native_test_view_ 是更新数据的通信标识
		MethodChannel methodChannel = new MethodChannel(messenger, "com.flutter_to_native_test_textview_" + id);
		methodChannel.setMethodCallHandler(this);
	}
	
	... ...
	
	@Override
	public void onMethodCall(MethodCall methodCall, MethodChannel.Result result) {

  //updateText 是flutter 中调用的方法名称，可以随意定义
		if ("updateText".equals(methodCall.method)) {
			String text = (String) methodCall.arguments;
			this.mTestTextView .setText(text);
			//对flutter 的回调
			result.success(null);
		}
	}
}

 MethodChannel _channel;
 int viewId=0;

   mTextWidget = Container(
   height: 200,
   child: AndroidView(
    //标识
    viewType: "com.flutter_to_native_test_textview",
    creationParams: {
    "content": "flutter 传入的文本内容",
    },
    //参数的编码方式
    creationParamsCodec: const StandardMessageCodec(),
    //view创建完成时的回调
    onPlatformViewCreated: (id) {
    viewId = id;
    },
   ),
   );

//这里设置的标识 MethodChannel('com.flutter_to_native_test_textview_$viewId');
// 与android MethodChannel methodChannel = new MethodChannel(messenger, "com.flutter_to_native_test_textview_" + id); 中注册的一至
void clickUpdtae(){
_channel = new MethodChannel('com.flutter_to_native_test_textview_$viewId');
 updateTextView();
}

//这里的标识 updateText
//与android 中接收消息的方法中
//if ("updateText".equals(methodCall.method)) {...} 一至
void updateTextView() async {
 return _channel.invokeMethod('updateText', "更新内容");
 }