您需要在AndroidManifest中声明这些权限和服务：

<uses-permission android:name="android.permission.MANAGE_OWN_CALLS"/>
<uses-permission android:name="android.permission.READ_CALL_LOG"/>

<!-- Needed only if your calling app reads numbers from the `PHONE_STATE` intent action. -->
<uses-permission android:name="android.permission.READ_PHONE_STATE"/>

<service android:name="com.example.MyConnectionService"
    android:permission="android.permission.BIND_TELECOM_CONNECTION_SERVICE">
    <intent-filter>
        <action android:name="android.telecom.ConnectionService" />
    </intent-filter>
</service>

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然后您可以通过设置将其设置为默认拨号。