最近Flutter推出了WebView预览版，采用原生组件嵌入到Flutter中，今天特地查阅了一下FlutterWebView的实现，然后试着写了一下EditText嵌入到Flutter，然后结果是成功的，但是输入框键盘不能弹出。。。

第一步，创建FlutterEditTextView， 实现接口类：PlatformView, MethodChannel.MethodCallHandler

代码如下：

import android.content.Context

import android.view.View

import android.widget.EditText

import io.flutter.plugin.common.BinaryMessenger

import io.flutter.plugin.common.MethodCall

import io.flutter.plugin.common.MethodChannel

import io.flutter.plugin.platform.PlatformView

class FlutterEditTextView : PlatformView, MethodChannel.MethodCallHandler {

private var editText: EditText

private val methodChannel: MethodChannel

constructor(context: Context?, id: Int, args: Map?, messenger: BinaryMessenger?) {

editText = EditText(context)

editText.setText(

when {

args?.containsKey("text") == true -> args["text"].toString()

else -> ""

}

)

if (args?.containsKey("textColor") == true && args["textColor"] != null)

editText.setTextColor(args["textColor"]!!.toString().toInt())

editText.hint = when {

args?.containsKey("text") == true -> args["text"].toString()

else -> ""

}

if (args?.containsKey("hintTextColor") == true && args["hintTextColor"] != null)

editText.setHintTextColor(args["hintTextColor"]!!.toString().toInt())

methodChannel = MethodChannel(messenger, "plugins.demo.cn/editor_$id")

methodChannel.setMethodCallHandler(this)

}

override fun getView(): View = editText

override fun dispose() {

}

override fun onMethodCall(methodCall: MethodCall?, result: MethodChannel.Result?) {

}

}

第二步，实现Factory类, 继承PlatformViewFactory

class FlutterEditTextViewFactory(private val messenger: BinaryMessenger) :

PlatformViewFactory(StandardMessageCodec.INSTANCE) {

override fun create(context: Context?, id: Int, args: Any?): PlatformView =

FlutterEditTextView(context, id, args as? Map?, messenger)

}

第三步，实现Plugin类

object FlutterEditTextViewPlugin {

const val ChannelName = "com.mrper.hotpot.core.flutter.plugin.FlutterEditTextViewPlugin"

@JvmStatic

fun registerWith(registrar: Registrar) {

registrar

.platformViewRegistry()

.registerViewFactory(

"plugins.demo.cn/editor", FlutterEditTextViewFactory(registrar.messenger())

)

}

}

第四步，注册插件

val ChannelName = "com.demo.flutter/activity_channel"

if (!pluginRegistry.hasPlugin(FlutterEditTextViewPlugin.ChannelName))

FlutterEditTextViewPlugin.registerWith(pluginRegistry.registrarFor(FlutterEditTextViewPlugin.ChannelName))

第五步，Flutter端实现EditText组件

import 'package:flutter/foundation.dart';

import 'package:flutter/gestures.dart';

import 'package:flutter/material.dart';

import 'package:flutter/services.dart';

typedef void EditTextCreatedCallback(EditTextController controller);

class EditText extends StatefulWidget {

const EditText({

Key key,

this.text,

this.textColor,

this.hint,

this.hintTextColor,

this.onEditTextCreated,

this.gestureRecognizers,

}) : super(key: key);

final String text;

final int textColor;

final String hint;

final int hintTextColor;

final EditTextCreatedCallback onEditTextCreated;

final Set> gestureRecognizers;

@override

State createState() => _EditTextState();

}

class _EditTextState extends State {

@override

Widget build(BuildContext context) {

return AndroidView(

viewType: "plugins.demo.cn/editor",

onPlatformViewCreated: (id) {},

layoutDirection: TextDirection.ltr,

creationParams: _CreationParams.fromWidget(widget).toMap(),

gestureRecognizers: widget.gestureRecognizers,

creationParamsCodec: const StandardMessageCodec(),

);

}

}

class _CreationParams {

_CreationParams({

this.text,

this.textColor,

this.hint,

this.hintTextColor,

});

static _CreationParams fromWidget(EditText widget) {

return _CreationParams(

text: widget.text,

textColor: widget.textColor,

hint: widget.hint,

hintTextColor: widget.hintTextColor);

}

final String text;

final int textColor;

final String hint;

final int hintTextColor;

Map toMap() {

return {

'text': text,

'textColor': textColor,

'hint': hint,

'hintTextColor': hintTextColor,

};

}

}

class EditTextController {

EditTextController._(int id)

: _channel = MethodChannel('plugins.demo.cn/editor_$id');

final MethodChannel _channel;

}

第六步，Good Job! 你能在你的布局中使用EditText了，但是效果肯定是。。。让你无语的，哈哈，暂时就这样，毕竟还只是个实验性的功能！