开始通话时拨打phoneSpeakers

Question

我在使用按钮开始通话后尝试打开扬声器。但议长没有开启。我的代码：

我试过audioManager.setMode（AudioManager.MODE_IN_CALL）;但它没有用。

我做错了什么？

MainActivity.java

package app.fabi.telefon_freisprech;

import android.Manifest;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.media.AudioManager;
import android.net.Uri;
import android.os.Build;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;


public class MainActivity extends AppCompatActivity {

    private Button button;
    AudioManager audioManager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        button = (Button) findViewById(R.id.buttonCall);


        button.setOnClickListener(new View.OnClickListener() {
            public void onClick(View arg0) {


                check();

                Intent myIntent = new Intent(Intent.ACTION_CALL);
                String phNum = "tel:" + "+123456789";
                myIntent.setData(Uri.parse(phNum));

                startActivity( myIntent ) ;


                audioManager = (AudioManager)getApplicationContext().getSystemService(Context.AUDIO_SERVICE);
                audioManager.setMode(AudioManager.MODE_IN_COMMUNICATION);
                audioManager.setSpeakerphoneOn(true);



            }
        });

    }

    void check(){

        if (ContextCompat.checkSelfPermission(MainActivity.this,
                Manifest.permission.CALL_PHONE)
                != PackageManager.PERMISSION_GRANTED) {

            // first check for permissions
            if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CALL_PHONE) !=
                    PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this,
                    Manifest.permission.CALL_PHONE) != PackageManager.PERMISSION_GRANTED) {
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                    requestPermissions(new String[]{Manifest.permission.CALL_PHONE,
                                    Manifest.permission.CALL_PHONE, Manifest.permission.CALL_PHONE}
                            , 10);
                }
                return;
            }

        }

    }

}

activity_main.xml中

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <Button
        android:id="@+id/buttonCall"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Anrufen +123456789" />

</LinearLayout>

的AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="app.fabi.telefon_freisprech">

    <uses-permission android:name="android.permission.CALL_PHONE" />
    <uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

我认为它不是一件大事，但我不能让它发挥作用。