CODEWITHSUNDEEP
androidkotlinflutter
Kyoung-june Yi
Kyoung-june Yi

Reputation: 533

How to pass arguments from Flutter to Kotlin?

i've got started studying Flutter. I'm trying to using MethodChannel and MethodCall to communicate with Android platform. I don't know how to pass arguments to the Android code.

Below is my code.

// dart
void _onClick() async {
    var parameters = {'image':'starry night'};
    await platform.invokeMethod('showToast', new Map.from(parameters));
}


// kotlin
MethodChannel(flutterView, CHANNEL).setMethodCallHandler { call, result ->
    Log.d("MainActivity", ">> ${call.method}, ${call.arguments}")
    when (call.method) {
        "showToast" -> {
        showToast("toast")
    }
    else -> {
        Log.d("MainActivity", "fail");
    }
}

I can check an arguement value what I passed by log message what I printed. {image=starry night} But I don't know how to parse to a map object.

Upvotes: 22

Views: 14965

Answers (2)

CopsOnRoad
CopsOnRoad

Reputation: 268024

Dart side (sending data)

var channel = MethodChannel('foo_channel');
var dataToPass = <String, dynamic>{
  'os': 'Android',
};
await channel.invokeListMethod<String>('methodInJava', dataToPass);

Java side (receiving data):

if (methodCall.method.equals("methodInJava")) {
    // Get the entire Map.
    HashMap<String, Object> map = (HashMap<String, Object>) methodCall.arguments;
    Log.i("MyTag", "map = " + map); // {os=Android}

    // Or get a specific value.
    String value = methodCall.argument("os");
    Log.i("MyTag", value); // Android
}

Upvotes: 6

Suragch
Suragch

Reputation: 512186

Flutter

On the Flutter side, you can pass arguments by including them as a map in the invokeMethod call.

_channel.invokeMethod('showToast', {'text': 'hello world'});

Kotlin

On the Kotlin side you can get the parameters by casting call.arguments as a Map or getting a particular argument from call.argument().

override fun onMethodCall(call: MethodCall, result: Result) {
  when (call.method) {
    "showToast" -> {
      val text = call.argument<String>("text") // hello world
      showToast(text)
    }   
  }
}

Upvotes: 31

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