Question

我在android中实现了一个客户端套接字。但它运行时崩溃其实我试图用android控制一个linux系统。所以服务器是linux。这是我的代码

package com.example.clientsocket;


import java.io.OutputStreamWriter;
import java.net.Socket;

import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

@SuppressLint("HandlerLeak")
public class MainActivity extends Activity {
TextView serverMessage;
Thread m_objThreadClient;
Socket clientSocket;
private SensorManager sensorManager;
private long lastUpdate;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    serverMessage=(TextView)findViewById(R.id.textView1);


    sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
    lastUpdate = System.currentTimeMillis();
Button b=(Button)findViewById(R.id.button1);
b.setOnClickListener(new View.OnClickListener() {

      public void onClick(View v) 
{

    m_objThreadClient=new Thread(new Runnable() {
          public void run()
      {
          try 
          {
              EditText ipt=(EditText)findViewById(R.id.editText1);
                String ip=ipt.getText().toString();
                Socket sock = new Socket("192.168.42.130",20056);
                OutputStreamWriter osw = new OutputStreamWriter(sock.getOutputStream());
                char a='g';
                osw.write(a);
                osw.flush();


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

        }
            });

    m_objThreadClient.start();

}
});
}

public void onSensorChanged(SensorEvent event) {
  if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
    getAccelerometer(event);
  }

}

private void getAccelerometer(SensorEvent event) {
    float[] values = event.values;
    // Movement

    float y = values[1];




    long actualTime = System.currentTimeMillis();
    if (y>3 ) //
    {
      if (actualTime - lastUpdate < 200) {
    return;
      }
      lastUpdate = actualTime;
      m_objThreadClient=new Thread(new Runnable() {
          public void run()
      {
      try 
      {
      EditText ipt=(EditText)findViewById(R.id.editText1);
        String ip=ipt.getText().toString();
            Socket sock = new Socket("192.168.42.130",20056);
            OutputStreamWriter osw = new OutputStreamWriter(sock.getOutputStream());
            char a='r';
            osw.write(a);
            osw.flush();


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

    }
        });

m_objThreadClient.start();




    }
  }

  public void onAccuracyChanged(Sensor sensor, int accuracy) {

  }

  @Override
  protected void onResume() {
    super.onResume();
    // register this class as a listener for the orientation and
    // accelerometer sensors
    sensorManager.registerListener((SensorEventListener) this,
        sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),
        SensorManager.SENSOR_DELAY_NORMAL);
  }

  @Override
  protected void onPause() {
    // unregister listener
    super.onPause();
    sensorManager.unregisterListener((SensorListener) this);
  }




Handler mHandler = new Handler() {
    @Override
    public void handleMessage(Message msg) {
        messageDisplay(msg.obj.toString());
    }
};
public void messageDisplay(String servermessage)
{
    serverMessage.setText(""+servermessage);
}

}

logcat是

09-09 22:36:46.000: D/SensorManager(3492): ====>>>>>Num Sensor: 1
09-09 22:36:46.000: D/SensorManager(3492): ====>>>>>Num Sensor: 2
09-09 22:36:46.000: D/SensorManager(3492): ====>>>>>Num Sensor: 3
09-09 22:36:46.000: D/SensorManager(3492): ====>>>>>Num Sensor: 4
09-09 22:36:46.000: D/SensorManager(3492): ====>>>>>Num Sensor: 5
09-09 22:36:46.000: D/SensorManager(3492): ====>>>>>Num Sensor: 6
09-09 22:36:46.000: D/SensorManager(3492): ====>>>>>Num Sensor: 0
09-09 22:36:46.000: D/AndroidRuntime(3492): Shutting down VM
09-09 22:36:46.000: W/dalvikvm(3492): threadid=1: thread exiting with uncaught exception (group=0x40018578)
09-09 22:36:46.007: E/AndroidRuntime(3492): FATAL EXCEPTION: main
09-09 22:36:46.007: E/AndroidRuntime(3492): java.lang.RuntimeException: Unable to resume activity {com.example.clientsocket/com.example.clientsocket.MainActivity}: java.lang.ClassCastException: com.example.clientsocket.MainActivity
09-09 22:36:46.007: E/AndroidRuntime(3492):     at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2124)
09-09 22:36:46.007: E/AndroidRuntime(3492):     at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2139)
09-09 22:36:46.007: E/AndroidRuntime(3492):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1672)
09-09 22:36:46.007: E/AndroidRuntime(3492):     at android.app.ActivityThread.access$1500(ActivityThread.java:117)
09-09 22:36:46.007: E/AndroidRuntime(3492):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:935)
09-09 22:36:46.007: E/AndroidRuntime(3492):     at android.os.Handler.dispatchMessage(Handler.java:99)
09-09 22:36:46.007: E/AndroidRuntime(3492):     at android.os.Looper.loop(Looper.java:130)
09-09 22:36:46.007: E/AndroidRuntime(3492):     at android.app.ActivityThread.main(ActivityThread.java:3687)
09-09 22:36:46.007: E/AndroidRuntime(3492):     at java.lang.reflect.Method.invokeNative(Native Method)
09-09 22:36:46.007: E/AndroidRuntime(3492):     at java.lang.reflect.Method.invoke(Method.java:507)
09-09 22:36:46.007: E/AndroidRuntime(3492):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
09-09 22:36:46.007: E/AndroidRuntime(3492):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625)
09-09 22:36:46.007: E/AndroidRuntime(3492):     at dalvik.system.NativeStart.main(Native Method)
09-09 22:36:46.007: E/AndroidRuntime(3492): Caused by: java.lang.ClassCastException: com.example.clientsocket.MainActivity
09-09 22:36:46.007: E/AndroidRuntime(3492):     at com.example.clientsocket.MainActivity.onResume(MainActivity.java:139)
09-09 22:36:46.007: E/AndroidRuntime(3492):     at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1150)
09-09 22:36:46.007: E/AndroidRuntime(3492):     at android.app.Activity.performResume(Activity.java:3832)
09-09 22:36:46.007: E/AndroidRuntime(3492):     at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2114)
09-09 22:36:46.007: E/AndroidRuntime(3492):     ... 12 more

Answer 1

错误是您尝试在onResume方法中将MainActivity强制转换为SensorEventListener。您需要A SensorEventListener object.作为函数的第一个参数，而不是尝试转换当前活动。

你需要：

Implement SensorEventListener in your Activity。

然后您可以将this作为第一个参数传递。像这样：

sensorManager.registerListener(this,
        sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),
        SensorManager.SENSOR_DELAY_NORMAL);

Answer 2

您的活动必须实现SensorEventListner，如下所示：

public class MainActivity extends Activity implements SensorEventListener {

Android客户端意外停止

2 个答案: