Android App停止工作

Question

我目前正在开发一个android应用程序，它可以通过网络向AV接收器发送命令。我已经得到了尽可能多的按钮和编码，这样当按钮被点击时，它会发送命令PWON \ r到指定的IP和端口。我还在清单文件中给出了完整的互联网许可。问题是，只要按下按钮，应用程序就会停止工作。我不确定问题是什么。

CODE：

package av.control.test; 
import java.io.IOException; 
import java.io.OutputStream; 
import java.net.Socket; 
import java.net.UnknownHostException; 
import android.app.Activity; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.Button; 

public class AVControlActivity extends Activity { 

Button mbutt; 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 
    mbutt = (Button)findViewById(R.id.Button); 
} 
public void onClick(View view) throws UnknownHostException, IOException 
{ 
    new Thread() { 
     public void run() { 
      Socket socket = null; 
      try { 
       socket = new Socket("192.168.1.74", 23); 
      } catch (UnknownHostException e1) { 
       // TODO Auto-generated catch block 
       e1.printStackTrace(); 
      } catch (IOException e1) { 
       // TODO Auto-generated catch block 
       e1.printStackTrace(); 
      } 
      try{ 
       dataOutputStream.Object BUFFER = null; 
       write(BUFFER); 
       String buffer="PWON\r"; 
       OutputStream os=socket.getOutputStream(); 
       os.write(buffer.getBytes()); 
      } catch(IOException e) 
      { 
       //error code 
      } 
      } 
     }.start(); 
} 
private void write(Object BUFFER) { 
    // TODO Auto-generated method stub 

} 
} 

下面是main.xml中，以及如果这是任何使用：

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="fill_parent" 
android:layout_height="fill_parent" 
android:orientation="vertical" > 

<TextView 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello" /> 

<Button 
    android:id="@+id/Button" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="Power On" 
    android:onClick="onClick" /> 

</LinearLayout> 

我希望得到任何帮助。

编辑：

logcat的

09-15 14:31:30.742: I/dalvikvm(1209): threadid=3: reacting to signal 3 
09-15 14:31:31.301: E/dalvikvm(1209): Unable to open stack trace file '/data/anr/traces.txt': Permission denied 
09-15 14:31:31.322: I/dalvikvm(1209): threadid=3: reacting to signal 3 
09-15 14:31:31.421: I/dalvikvm(1209): Wrote stack traces to '/data/anr/traces.txt' 
09-15 14:31:31.801: I/dalvikvm(1209): threadid=3: reacting to signal 3 
09-15 14:31:31.901: I/dalvikvm(1209): Wrote stack traces to '/data/anr/traces.txt' 
09-15 14:31:32.381: I/dalvikvm(1209): threadid=3: reacting to signal 3 
09-15 14:31:32.451: I/dalvikvm(1209): Wrote stack traces to '/data/anr/traces.txt' 
09-15 14:31:32.711: D/gralloc_goldfish(1209): Emulator without GPU emulation detected. 
09-15 14:31:32.843: I/dalvikvm(1209): threadid=3: reacting to signal 3 
09-15 14:31:32.901: I/dalvikvm(1209): Wrote stack traces to '/data/anr/traces.txt' 
09-15 14:34:53.081: W/System.err(1209): java.net.ConnectException: failed to connect to  /192.168.1.74 (port 23): connect failed: ETIMEDOUT (Connection timed out) 
09-15 14:34:53.091: W/System.err(1209):  at libcore.io.IoBridge.connect(IoBridge.java:114) 
09-15 14:34:53.091: W/System.err(1209):  at  java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192) 
09-15 14:34:53.101: W/System.err(1209):  at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172) 
09-15 14:34:53.121: W/System.err(1209):  at java.net.Socket.startupSocket(Socket.java:566) 
09-15 14:34:53.121: W/System.err(1209):  at java.net.Socket.tryAllAddresses(Socket.java:127) 
09-15 14:34:53.132: W/System.err(1209):  at java.net.Socket.<init>(Socket.java:177) 
09-15 14:34:53.132: W/System.err(1209):  at java.net.Socket.<init>(Socket.java:149) 
09-15 14:34:53.161: W/System.err(1209):  at av.control.test.AVControlActivity$1.run(AVControlActivity.java:27) 
09-15 14:34:53.161: W/System.err(1209): Caused by: libcore.io.ErrnoException: connect failed: ETIMEDOUT (Connection timed out) 
09-15 14:34:53.182: W/System.err(1209):  at libcore.io.Posix.connect(Native Method) 
09-15 14:34:53.182: W/System.err(1209):  at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:85) 
09-15 14:34:53.191: W/System.err(1209):  at libcore.io.IoBridge.connectErrno(IoBridge.java:127) 
09-15 14:34:53.211: W/System.err(1209):  at libcore.io.IoBridge.connect(IoBridge.java:112) 
09-15 14:34:53.211: W/System.err(1209):  ... 7 more 
09-15 14:34:53.222: W/dalvikvm(1209): threadid=12: thread exiting with uncaught exception (group=0x409c01f8) 
09-15 14:34:53.241: E/AndroidRuntime(1209): FATAL EXCEPTION: Thread-121 
09-15 14:34:53.241: E/AndroidRuntime(1209): java.lang.NullPointerException 
09-15 14:34:53.241: E/AndroidRuntime(1209):  at av.control.test.AVControlActivity$1.run(AVControlActivity.java:39) 

Answer 1

您对

OutputStream os=socket.getOutputStream(); 

这是因为以下行给了一个例外，由于超时一个空指针异常。

socket = new Socket("192.168.1.74", 23); 

所以socket仍然是空的。如果没有创建套接字，我不认为你应该继续操作。因此请像下面那样更改您的代码

try { 
      socket = new Socket("192.168.1.74", 23); 
      dataOutputStream.Object BUFFER = null; 
      write(BUFFER); 
      String buffer="PWON\r"; 
      OutputStream os=socket.getOutputStream(); 
      os.write(buffer.getBytes()); 
     } catch (UnknownHostException e1) { 
      e1.printStackTrace(); 
     } catch (IOException e1) { 
      e1.printStackTrace(); 
     } 

此外，请检查你为什么超时。这可能是由于设备不在同一网络上，或端口未打开。