Android开关小部件强制关闭

尝试在android中创建一个开关，默认状态为ON，OnCheckedChangeListener。但应用程序是强制关闭。怎么了？请帮忙。android开发中的新技术

package com.tiumca2013.smarthousecontrol;

import android.app.Activity;
import android.app.Fragment;
import android.bluetooth.BluetoothAdapter;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.Switch;
import android.widget.Toast;

public class MainActivity extends Activity{
private Switch switch1;

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

    switch1 = (Switch) findViewById(R.id.Switch1);

    switch1.setChecked(true); // force close

    switch1.setOnCheckedChangeListener(new OnCheckedChangeListener()        // force close again
    {   
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked)
        {
            if(isChecked)
                Toast.makeText(getApplicationContext(),"switch 1 ON",Toast.LENGTH_SHORT).show(); 
            else
                Toast.makeText(getApplicationContext(),"switch 1 OFF",Toast.LENGTH_SHORT).show(); 
        }
    });


   if (savedInstanceState == null) {
        getFragmentManager().beginTransaction()
                .add(R.id.container, new PlaceholderFragment())
                .commit();
    } 


}


@Override
public boolean onCreateOptionsMenu(Menu menu) {

    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

/**
 * A placeholder fragment containing a simple view.
 */
public static class PlaceholderFragment extends Fragment {

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main, container, false);
        return rootView;
    }
}

}

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使用Genymotion AVD而不是默认的AVD你有什么版本的android？4.1.2@commonware-我的DDMS logcat显示了数百个错误。在我看来，问题是NullPointException。当我使用try-catch块处理这个问题时，应用程序正在执行，没有任何错误，但再次执行switch1.setChecked（true）；它不起作用。