android 应用程序在调试时出现强制关闭的信息，造成这种情况的可能性有哪些以及具体的解决方法

主程序 Demo：
package softdevonline.Demo;

import java.io.IOException;

import org.ksoap2.SoapEnvelope;
import org.ksoap2.serialization.SoapObject;
import org.ksoap2.serialization.SoapSerializationEnvelope;
import org.ksoap2.transport.HttpTransportSE;
import org.xmlpull.v1.XmlPullParserException;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo.State;
import android.os.Bundle;
import android.provider.Settings;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class Demo extends Activity {

//String Text;
String LoginVertifyResult;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        if(checkNetworkInfo())
        {
         Button ConfrimButton=(Button)findViewById(R.id.Button1);
            ConfrimButton.setOnClickListener(new View.OnClickListener()
            {
         public void onClick(View v)
         {
         //LoadProgressDialog();
         showContent();
         }
            });
        }
    }

    private boolean checkNetworkInfo()
    {

ConnectivityManager conMan = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);//获取网络通讯类的实例
     //mobile 3G Data Network
State mobile=  conMan.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState();//TYPE_MOBILE=0
     //txt3G.setText(mobile.toString());
     //wifi
     State wifi = conMan.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState();//TYPE_MOBILE=1
     //txtWifi.setText(wifi.toString());

     //如果3G网络和wifi网络都未连接，且不是处于正在连接状态则进入Network Setting界面由用户配置网络连接

     if(mobile==State.CONNECTED||mobile==State.CONNECTING)
     {
     Toast.makeText(this, "移动网络已开启。", Toast.LENGTH_SHORT).show();
     return false;
     }
     else
     {
     if(wifi==State.CONNECTED||wifi==State.CONNECTING)
     {
     Toast.makeText(this, "Wifi已开启。", Toast.LENGTH_SHORT).show();
     return false;
     }
     Toast.makeText(this, "请开启无线网络！", Toast.LENGTH_SHORT).show();
     }

     Intent tmpIntent=new Intent(Settings.ACTION_WIRELESS_SETTINGS);
startActivityForResult(tmpIntent,0);
return true;
     //startActivity(new Intent(Settings.ACTION_WIRELESS_SETTINGS));//进入无线网络配置界面
     //startActivity(new Intent(Settings.ACTION_WIFI_SETTINGS)); //进入手机中的wifi网络设置界面
}

    private final String namespace="http://tempuri.org/";
    private String URL="http://192.168.10.11:8800/SmartWebService/Service1.asmx";
    private String method_name="LoginVertify";
    private String soap_action="http://tempuri.org/LoginVertify";
    private SoapObject soap;
//private SoapPrimitive soapPri;
private void showContent() {
// TODO Auto-generated method stub
try
{
//AndroidHttpTransport ht=new AndroidHttpTransport(URL);
//HttpPost request=new HttpPost(URL);
EditText tmpUserNameEditText=(EditText)findViewById(R.id.UserName);
     //tmpUserNameEditText.setText(Text);
String LoginName=tmpUserNameEditText.getText().toString();
     EditText tmpPasswordEditText=(EditText)findViewById(R.id.Password);
     String Password=tmpPasswordEditText.getText().toString();

HttpTransportSE ht=new HttpTransportSE(URL);
ht.debug=true;
SoapObject rpc=new SoapObject(namespace, method_name);
if(LoginName!=""&&Password!="")
{
rpc.addProperty("prmUserName", LoginName);
rpc.addProperty("prmUserPassword", Password);
}
SoapSerializationEnvelope envelope=new SoapSerializationEnvelope(SoapEnvelope.VER11);
envelope.bodyOut=ht;
envelope.dotNet=true;
envelope.setOutputSoapObject(rpc);
try
{
ht.call(soap_action, envelope);//运行到此出异常
soap =(SoapObject)envelope.bodyIn;
//Text=envelope.getResponse().toString();
//Log.e("xml", Text);

          Intent intent=new Intent();
     intent.setClass(Demo.this, Login.class);

          LoginVertifyResult=envelope.getResponse().toString();
          Bundle tmpbundle=new Bundle();
          tmpbundle.putString("LoginName", LoginVertifyResult);
          tmpbundle.putString("Password", Password);
          intent.putExtras(tmpbundle);

          /*
          if(LoginVertifyResult=="Success...")
     {

     }
          else
          {
          Bundle tmpbundle=new Bundle();
              tmpbundle.putString("LoginName",LoginVertifyResult);
              tmpbundle.putString("Password", "");
              intent.putExtras(tmpbundle);
          }
          */
          startActivity(intent);
}
catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
}
catch (XmlPullParserException e)
//catch(Exception e)
{
e.printStackTrace();
}
}}

配置文件：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="softdevonline.Demo" android:versionCode="1"
android:versionName="1.0.0">
<application android:icon="@drawable/icon" android:label="@string/app_name">
<uses-library android:name="com.google.android.maps"></uses-library>
<activity android:name=".Demo" android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<action android:name="android.net.conn.CONNECTIVITY_CHANGE"/>
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name="Login"></activity>
<activity android:name="GridViewDemo"></activity>
<activity android:name="Listview"></activity>
<activity android:name="ImageViewDemo"></activity>
<activity android:name="MapView"></activity>
</application>
<uses-sdk android:minSdkVersion="8" />
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<receiver android:name="com.blackboard.androidtest.receiver.ConnectionChangeReceiver"
          android:label="NetworkConnection"/>
</manifest>

Console：
[2011-08-02 10:48:01 - Demo] ------------------------------
[2011-08-02 10:48:01 - Demo] Android Launch!
[2011-08-02 10:48:01 - Demo] adb is running normally.
[2011-08-02 10:48:01 - Demo] No Launcher activity found!
[2011-08-02 10:48:01 - Demo] The launch will only sync the application package on the device!
[2011-08-02 10:48:01 - Demo] Performing sync
[2011-08-02 10:48:07 - Demo] Application already deployed. No need to reinstall.
[2011-08-02 10:48:07 - Demo] \Demo\bin\Demo.apk installed on device
[2011-08-02 10:48:07 - Demo] Done!

在运行到对Button的Click事件进行监听时，出现强制关闭。 --------------------编程问答-------------------- No Launcher activity found!

AndroidManifest.xml看看有没问题
看看activity有没注册对有没加下面这段



            <intent-filter>

                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />

            </intent-filter>

--------------------编程问答-------------------- 楼上的加了，还是强制关闭，应该不是这个原因 --------------------编程问答-------------------- 强制关闭的原因多了去了，我的经验是单步执行，肯定是某个地方出错了，没有被代码捕获到或者没有去捕获，才会直接强制关闭。

另外，如果涉及硬件环境，那必须确认是否有该硬件，然后是否赋予了访问这个硬件的环境，还有，就是可能涉及网络环境，是否确实满足你的预设要求。 --------------------编程问答-------------------- 网络有允许不，调试信息拿出来瞧瞧

补充：移动开发 ,  Android