Question

我不知道为什么会这样。有人可以帮帮我吗？

客户类：

public class Cliente extends AsyncTask<Void,String,Void> {

    String dstAddress;
    int dstPort;
    TextView x_atual,y_atual,x_desejado,y_desejado;
    Scanner r;
    String[] valores = new String[4];

    public Cliente(String addr, int port) {
        //super();
        dstAddress = addr;
        dstPort = port;
    }

    public Cliente(TextView x_atual,TextView y_atual, TextView x_desejado, TextView y_desejado) {
        //super();
        this.x_atual = x_atual;
        this.y_atual = y_atual;
        this.x_desejado = x_desejado;
        this.y_desejado = y_desejado;
    }

    @Override
    protected Void doInBackground(Void... params) {

        Socket socket = null;

        try {
            socket = new Socket(dstAddress, dstPort);

            r = new Scanner(new InputStreamReader(socket.getInputStream()));

        } catch (UnknownHostException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        valores[0] = r.nextLine();
        valores[1] = r.nextLine();
        valores[2] = r.nextLine();
        valores[3] = r.nextLine();
        publishProgress(valores[0],valores[1],valores[2],valores[3]);
    try {
    Thread.sleep(60);
     } catch (InterruptedException e) {
    e.printStackTrace();
    }
        return null;
    }

    @Override
    protected void onPostExecute(Void result) {
        x_atual.setText(valores[0]);
        y_atual.setText(valores[1]);
        x_desejado.setText(valores[2]);
        y_desejado.setText(valores[3]);
       super.onPostExecute(result);
    }

     }

的活动：

public class SecondActivity extends AppCompatActivity {

TextView x_atual,y_atual,x_desejado,y_desejado;
Cliente myClient;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_second);

    x_atual = (TextView) findViewById(R.id.x_atual);
    y_atual = (TextView) findViewById(R.id.y_atual);
    x_desejado = (TextView) findViewById(R.id.x_desej);
    y_desejado = (TextView) findViewById(R.id.y_desej);

    x_atual.setText("0");
    y_atual.setText("0");
    x_desejado.setText("0");
    y_desejado.setText("0");

    myClient = new Cliente(x_atual,y_atual,x_desejado,y_desejado);
    myClient.execute();
}




}

处理：com.example.tiago.java_android，PID：8129 java.lang.NullPointerException：尝试调用虚方法'void android.widget.TextView.setText（java.lang.CharSequence）'为null 对象参考在 com.example.tiago.java_android.Cliente.onPostExecute（Cliente.java:73）在 com.example.tiago.java_android.Cliente.onPostExecute（Cliente.java:18）在android.os.AsyncTask.finish（AsyncTask.java:636）在android.os.AsyncTask.access $ 500（AsyncTask.java:177）在 android.os.AsyncTask $ InternalHandler.handleMessage（AsyncTask.java:653）在android.os.Handler.dispatchMessage（Handler.java:102）在android.os.Looper.loop（Looper.java:135）在android.app.ActivityThread.main（ActivityThread.java:5431） at java.lang.reflect.Method.invoke（Native Method）在java.lang.reflect.Method.invoke（Method.java:372）在 com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:914）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:707）

Java Android - 在null对象引用上的void android.widget.TextView.setText（java.lang.CharSequence）'

0 个答案: