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Java 如何从方法通道检索模型?_Java_Android_Flutter - Fatal编程技术网

Java 如何从方法通道检索模型?

Java 如何从方法通道检索模型?,java,android,flutter,Java,Android,Flutter,我想通过方法通道从本机Android检索一个模型。我当前的代码: new MethodChannel(getFlutterView(), CHANNEL).setMethodCallHandler( new MethodCallHandler() { @Override public void onMethodCall(MethodCall methodCall, Res

我想通过方法通道从本机Android检索一个模型。我当前的代码:

       new MethodChannel(getFlutterView(), CHANNEL).setMethodCallHandler(
                new MethodCallHandler() {
                    @Override
                    public void onMethodCall(MethodCall methodCall, Result result) {
                        if (methodCall.method.equals("getModel")) {
                            
                            NewModel model = new NewModel();
                            model.id = 1;
                            model.title = "Title is here!";

                            result.success(model);
                        }

                    }
                }
        );

这是我的
NewModel

class NewModel {
    public int id;
    public String title;
}
在颤振中,我使用相同的模型,并尝试使用以下代码获得响应:

NewModel response = await platformMethodChannel.invokeMethod('getModel');
以下是错误:

E/MethodChannel#com.methodchannel/test(25656):  at io.flutter.plugin.common.MethodChannel$IncomingMethodCallHandler.onMessage(MethodChannel.java:233)
E/MethodChannel#com.methodchannel/test(25656):  at io.flutter.embedding.engine.dart.DartMessenger.handleMessageFromDart(DartMessenger.java:85)
E/MethodChannel#com.methodchannel/test(25656):  at io.flutter.embedding.engine.FlutterJNI.handlePlatformMessage(FlutterJNI.java:692)
E/MethodChannel#com.methodchannel/test(25656):  at android.os.MessageQueue.nativePollOnce(Native Method)
E/MethodChannel#com.methodchannel/test(25656):  at android.os.MessageQueue.next(MessageQueue.java:326)
E/MethodChannel#com.methodchannel/test(25656):  at android.os.Looper.loop(Looper.java:183)
E/MethodChannel#com.methodchannel/test(25656):  at android.app.ActivityThread.main(ActivityThread.java:7211)
E/MethodChannel#com.methodchannel/test(25656):  at java.lang.reflect.Method.invoke(Native Method)
E/MethodChannel#com.methodchannel/test(25656):  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:494)
E/MethodChannel#com.methodchannel/test(25656):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:975)


我怎样才能解决这个问题


注意:我可以成功获得前面在中询问的唯一
字符串
响应和
字符串列表
响应。但是我买不到模型。因此,这不是一个重复的问题。

您可以将模型转换为JSON。然后可以将JSON转换为模型

首先,您需要在
Java
模型中添加
toString()
方法,如下所示:

class NewModel {
    public int id;
    public String title;

    @Override
    public String toString() {
        return   "{\"id\": "+id+",\"title\": \""+ title+"\"}";
    }
}
   new MethodChannel(getFlutterView(), CHANNEL).setMethodCallHandler(
            new MethodCallHandler() {
                @Override
                public void onMethodCall(MethodCall methodCall, Result result) {
                    if (methodCall.method.equals("getModel")) {
                        
                        NewModel model = new NewModel();
                        model.id = 1;
                        model.title = "Title is here!";

                        result.success(model.toString()); // In here!
                    }

                }
            }
    );
然后,您可以将模型转换为
String
,如下所示:

class NewModel {
    public int id;
    public String title;

    @Override
    public String toString() {
        return   "{\"id\": "+id+",\"title\": \""+ title+"\"}";
    }
}
   new MethodChannel(getFlutterView(), CHANNEL).setMethodCallHandler(
            new MethodCallHandler() {
                @Override
                public void onMethodCall(MethodCall methodCall, Result result) {
                    if (methodCall.method.equals("getModel")) {
                        
                        NewModel model = new NewModel();
                        model.id = 1;
                        model.title = "Title is here!";

                        result.success(model.toString()); // In here!
                    }

                }
            }
    );


您确定正在调用颤振中右侧
methodChannel
的方法吗?是。我可以得到一个字符串值。