Question

它是一个app-to-app调用Android应用程序早些时候我遇到了一些代码问题，也有一些例外，现在很好，但面临最后一个例外。对于应用程序的调用活动，这是我的代码

public class CallActivity extends AppCompatActivity  {
private com.sinch.android.rtc.calling.Call call;
private TextView callState;
private Button button;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.call);
    TextView callState = (TextView) findViewById(R.id.callState);
    Intent intent = getIntent();
    String callerId = intent.getStringExtra("callerId");
    final String recipientId = intent.getStringExtra("recipientId");
    final SinchClient sinchClient = Sinch.getSinchClientBuilder()
            .context(this)
            .userId(""+callerId)
            .applicationKey("c6a1ec06-3f48-4e2d-980c-021ea6d2c8ca")
            .applicationSecret("pH2/AwzRJkmFS2M3kQ1XcA==")
            .environmentHost("sandbox.sinch.com")
            .build();
    sinchClient.setSupportCalling(true);
    sinchClient.startListeningOnActiveConnection();
    sinchClient.start();
    sinchClient.getCallClient().addCallClientListener(new SinchCallClientListener());
    button = (Button) findViewById(R.id.button);
    button.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View view) {
            call.addCallListener(new SinchCallListener());
            if (call == null) {
                call = sinchClient.getCallClient().callUser(recipientId);
                button.setText("Hang Up");
            } else {
                call.hangup();

            } // make a call!
        }
    });
}
private class SinchCallListener implements CallListener {

    @Override
    public void onCallProgressing(com.sinch.android.rtc.calling.Call progressingCall) {
        callState.setText("ringing");
    }

    @Override
    public void onCallEstablished(com.sinch.android.rtc.calling.Call establishedCall) {
        callState.setText("connected");
        setVolumeControlStream(AudioManager.STREAM_VOICE_CALL);
    }

    @Override
    public void onCallEnded(com.sinch.android.rtc.calling.Call endedCall) {
        callState.setText("");
        call = null;
        button.setText("Call");
        setVolumeControlStream(AudioManager.USE_DEFAULT_STREAM_TYPE);
    }

    @Override
    public void onShouldSendPushNotification(com.sinch.android.rtc.calling.Call call, List<PushPair>pushPairs) {

    }
}

private class SinchCallClientListener implements com.sinch.android.rtc.calling.CallClientListener {
    @Override
    public void onIncomingCall(com.sinch.android.rtc.calling.CallClient callClient, com.sinch.android.rtc.calling.Call incomingCall) {
        call = incomingCall;
        call.answer();
        call.addCallListener(new SinchCallListener());
        button.setText("Hang Up");
    }
}

}

logcat说：

03-24 20:45:49.789 25058-25058/com.example.abhinav123.sinch2 E/AndroidRuntime: FATAL EXCEPTION: main
                                                                           Process: com.example.abhinav123.sinch2, PID: 25058
                                                                           Theme: themes:{}
                                                                           java.lang.NullPointerException: Attempt to invoke interface method 'void com.sinch.android.rtc.calling.Call.addCallListener(com.sinch.android.rtc.calling.CallListener)' on a null object reference
                                                                               at com.example.abhinav123.sinch2.CallActivity$1.onClick(CallActivity.java:49)
                                                                               at android.view.View.performClick(View.java:5204)
                                                                               at android.view.View$PerformClick.run(View.java:21158)
                                                                               at android.os.Handler.handleCallback(Handler.java:739)
                                                                               at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                               at android.os.Looper.loop(Looper.java:148)
                                                                               at android.app.ActivityThread.main(ActivityThread.java:5461)
                                                                               at java.lang.reflect.Method.invoke(Native Method)
                                                                               at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
                                                                               at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

第49行是：call.addCallListener（new SinchCallListener（））;

请帮助..

Answer 1

您刚刚在此处声明call：private com.sinch.android.rtc.calling.Call call;

但是在使用之前你还没有初始化它。

无法调用方法的异常

1 个答案: