Android 尝试在现有颤振应用程序中实现颤振触点示例

我正在尝试实现这里的flatter_contacts示例：在我现有的flatter应用程序中，但是我在调用kotlin方法时遇到了问题。据我所知，我已经完全镜像了这个功能，但是当我调用launchcontacts方法时，它抛出了一个缺少插件的异常。以下是错误：

E/flutter (10095): [ERROR:flutter/lib/ui/ui_dart_state.cc(148)] Unhandled Exception: MissingPluginException(No implementation found for method launch on channel flutter_contacts/launch_contacts)

当我运行expmle应用程序时，它在expmle应用程序中运行良好，因此我假设我遗漏了一些东西

主要活动代码：

 package com.lightbridge.flutter_contacts

 import android.app.Activity
 import android.content.Intent
 import android.os.Bundle
 import android.provider.ContactsContract
 import io.flutter.app.FlutterActivity
 import io.flutter.plugin.common.MethodChannel
 import io.flutter.plugins.GeneratedPluginRegistrant

 class MainActivity : FlutterActivity() {

var lastResult: MethodChannel.Result? = null

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    GeneratedPluginRegistrant.registerWith(this)

    MethodChannel(flutterView, CHANNEL).setMethodCallHandler { call, result ->
        lastResult = result
        launchContactActivity()
    }
}

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    super.onActivityResult(requestCode, resultCode, data)
    if (requestCode == REQUEST_CODE) {
        if (resultCode == Activity.RESULT_OK) {
            lastResult?.success("Done!")
        } else {
            lastResult?.error("Error", "Can't launch contacts", "")
        }
    }
}

private fun launchContactActivity() {
    val intent = Intent(Intent.ACTION_VIEW)
    intent.type = ContactsContract.Contacts.CONTENT_TYPE
    startActivityForResult(intent, REQUEST_CODE)
}

companion object {
    private const val CHANNEL = "flutter_contacts/launch_contacts"
    private const val REQUEST_CODE = 42
}
 }

要启动的Dart代码

   void launchContacts() async {
   try {
    await platform.invokeMethod('launch');
   } on PlatformException catch (e) {
    print("Failed to launch contacts: ${e.message}");
   }
  setState(() {
  });
 }

---

在setMethodCallHandler中，必须编写一条if语句来检查方法名称，然后执行它：

if (call.method == "launch")
     launchContactActivity()