Question

我已经看了很久了，但是我无法修复在尝试访问null对象上的ResolveInfo.serviceInfo时抛出的Null Pointer Exception。（从API 20开始服务时必须明确意图）

这是.aidl界面：

package com.example.playerclient;

interface AIDLinterface {
    void Play_Clip(int id);
    void Pause_Playback();
    void Resume_Playback();
    void Stop_Player();
}

以下是相关的客户端代码（onResume()是NPE的引发位置）

public class PlayerClientMain extends AppCompatActivity
{

    Button button;
    private AIDLinterface mAIDLinterface;
    private boolean mIsBound = false;

    private ServiceConnection mServiceConn = new ServiceConnection()
    {

        @Override
        public void onServiceConnected(ComponentName componentName, IBinder iservice)
        {
            Log.v("SERVICE CONNECTED", "SERVICE CONNECTED");
            mAIDLinterface = AIDLinterface.Stub.asInterface(iservice);

            Toast.makeText(getApplicationContext(), "service connected", Toast.LENGTH_SHORT).show();

            mIsBound = true;
        }

        @Override
        public void onServiceDisconnected(ComponentName componentName)
        {
            Log.v("SERVICE DISCONNECTED", "SERVICE DISCONNECTED");
            mAIDLinterface = null;
            Toast.makeText(getApplicationContext(), "service disconnected", Toast.LENGTH_SHORT).show();
            mIsBound = false;

        }
    };

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


    @Override
    protected void onResume()
    {
        super.onResume();

        if (!mIsBound)
        {
            boolean b = false;
            Intent i = new Intent(AIDLinterface.class.getName());

            ResolveInfo info = getPackageManager().resolveService(i, Context.BIND_AUTO_CREATE); //this is always null
            i.setComponent(new ComponentName(info.serviceInfo.packageName, info.serviceInfo.name)); //NPE because info is null

            b = bindService(i, this.mServiceConn, Context.BIND_AUTO_CREATE);

            if (b)
                Log.i("SUCCESS:", "bindService() success!");
            else
                Log.i("FAILURE:", "bindService() failed!");
        }
    }
}

服务代码不相关，因为无论如何我都无法访问bindService（）行。有什么想法吗？

Answer 1

我认为问题在于创建意图本身。

假设AIDLinterface.class是服务类，您应该像这样创建意图：

Intent i = new Intent(this, AIDLinterface.class);

有关详细信息，请参阅https://developer.android.com/guide/components/services.html

干杯〜

无法bindService Android（）

1 个答案: