Java 在android ToggleButton中放置onclicklistener时获取nullpointerexception

当我尝试在android e中的toggleButton中的侦听器中放置祝酒词时，get null pointer异常有人能帮我吗

代码如下：

private ToggleButton locationToggle;
    private Context context;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
        requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);
        setContentView(R.layout.settings);
        getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE,
                R.layout.title_bar);

        context = getApplicationContext();

        sensorAdapter = new SensorAdapter();

        ListView sensorListview = (ListView) findViewById(R.id.listViewSettings);
        sensorListview.setAdapter(sensorAdapter);

        locationToggle = (ToggleButton) findViewById(R.id.toggleButton1);

        // attach an OnClickListener
        locationToggle.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(context, "CARREGOU", Toast.LENGTH_LONG).show();
                // your click actions go here
            }
        });

public class SensorAdapter extends BaseAdapter {

    List<sensorItem> sensorList = getDataForListView();

    private ToggleButton locationToggle, photosToggle, soundToggle,
    orientationToggle, messagesToggle, batteryToggle, calendarToggle,
    accelerometerToggle, lightToggle, contactsToggle;

    @Override
    public int getCount() {
        return sensorList.size();
    }

    @Override
    public sensorItem getItem(int arg0) {
        return sensorList.get(arg0);
    }

    @Override
    public long getItemId(int arg0) {
        return arg0;
    }

    @Override
    public View getView(int arg0, View arg1, ViewGroup arg2) {

        if (arg1 == null) {
            LayoutInflater inflater = (LayoutInflater) Settings.this
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            arg1 = inflater.inflate(R.layout.listitem, arg2, false);
        }

        // TextView sensorName = (TextView)
        // arg1.findViewById(R.id.textView1);
        TextView sensorDescription = (TextView) arg1
                .findViewById(R.id.textView2);
        ImageView sensorImage = (ImageView) arg1
                .findViewById(R.id.imageView1);

        locationToggle = (ToggleButton) findViewById(R.id.toggleButton1);
        photosToggle = (ToggleButton) findViewById(R.id.toggleButton1);
        soundToggle = (ToggleButton) findViewById(R.id.toggleButton1);
        orientationToggle = (ToggleButton) findViewById(R.id.toggleButton1);
        messagesToggle = (ToggleButton) findViewById(R.id.toggleButton1);
        batteryToggle = (ToggleButton) findViewById(R.id.toggleButton1);
        calendarToggle = (ToggleButton) findViewById(R.id.toggleButton1);
        accelerometerToggle = (ToggleButton) findViewById(R.id.toggleButton1);
        lightToggle = (ToggleButton) findViewById(R.id.toggleButton1);
        contactsToggle = (ToggleButton) findViewById(R.id.toggleButton1);

        // attach an OnClickListener
        locationToggle.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(context, "CARREGOU", Toast.LENGTH_LONG).show();
                // your click actions go here
            }
        });

        sensorItem sensor = sensorList.get(arg0);

        // sensorName.setText(sensor.sensorName);
        sensorDescription.setText(sensor.sensorDescription);
        sensorImage.setBackground(sensor.sensorImage);

        return arg1;
    }

    public sensorItem getCodeLearnChapter(int position) {
        return sensorList.get(position);
    }

}

这是错误日志：

04-03 16:57:29.511: E/AndroidRuntime(10552): FATAL EXCEPTION: main
04-03 16:57:29.511: E/AndroidRuntime(10552): java.lang.RuntimeException: Unable to start activity ComponentInfo{main.inSituApp/main.inSituApp.Settings}: java.lang.NullPointerException
04-03 16:57:29.511: E/AndroidRuntime(10552):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
04-03 16:57:29.511: E/AndroidRuntime(10552):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
04-03 16:57:29.511: E/AndroidRuntime(10552):    at android.app.ActivityThread.access$600(ActivityThread.java:130)
04-03 16:57:29.511: E/AndroidRuntime(10552):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
04-03 16:57:29.511: E/AndroidRuntime(10552):    at android.os.Handler.dispatchMessage(Handler.java:99)
04-03 16:57:29.511: E/AndroidRuntime(10552):    at android.os.Looper.loop(Looper.java:137)
04-03 16:57:29.511: E/AndroidRuntime(10552):    at android.app.ActivityThread.main(ActivityThread.java:4745)
04-03 16:57:29.511: E/AndroidRuntime(10552):    at java.lang.reflect.Method.invokeNative(Native Method)
04-03 16:57:29.511: E/AndroidRuntime(10552):    at java.lang.reflect.Method.invoke(Method.java:511)
04-03 16:57:29.511: E/AndroidRuntime(10552):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
04-03 16:57:29.511: E/AndroidRuntime(10552):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
04-03 16:57:29.511: E/AndroidRuntime(10552):    at dalvik.system.NativeStart.main(Native Method)
04-03 16:57:29.511: E/AndroidRuntime(10552): Caused by: java.lang.NullPointerException
04-03 16:57:29.511: E/AndroidRuntime(10552):    at main.inSituApp.Settings.onCreate(Settings.java:64)
04-03 16:57:29.511: E/AndroidRuntime(10552):    at android.app.Activity.performCreate(Activity.java:5008)
04-03 16:57:29.511: E/AndroidRuntime(10552):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
04-03 16:57:29.511: E/AndroidRuntime(10552):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
04-03 16:57:29.511: E/AndroidRuntime(10552):    ... 11 more

我想不出这是怎么回事。始终为空指针异常

切换按钮位于listitem.xml文件中

编辑：

我更改了代码以初始化适配器内的切换按钮。代码如下：

private ToggleButton locationToggle;
    private Context context;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
        requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);
        setContentView(R.layout.settings);
        getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE,
                R.layout.title_bar);

        context = getApplicationContext();

        sensorAdapter = new SensorAdapter();

        ListView sensorListview = (ListView) findViewById(R.id.listViewSettings);
        sensorListview.setAdapter(sensorAdapter);

        locationToggle = (ToggleButton) findViewById(R.id.toggleButton1);

        // attach an OnClickListener
        locationToggle.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(context, "CARREGOU", Toast.LENGTH_LONG).show();
                // your click actions go here
            }
        });

public class SensorAdapter extends BaseAdapter {

    List<sensorItem> sensorList = getDataForListView();

    private ToggleButton locationToggle, photosToggle, soundToggle,
    orientationToggle, messagesToggle, batteryToggle, calendarToggle,
    accelerometerToggle, lightToggle, contactsToggle;

    @Override
    public int getCount() {
        return sensorList.size();
    }

    @Override
    public sensorItem getItem(int arg0) {
        return sensorList.get(arg0);
    }

    @Override
    public long getItemId(int arg0) {
        return arg0;
    }

    @Override
    public View getView(int arg0, View arg1, ViewGroup arg2) {

        if (arg1 == null) {
            LayoutInflater inflater = (LayoutInflater) Settings.this
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            arg1 = inflater.inflate(R.layout.listitem, arg2, false);
        }

        // TextView sensorName = (TextView)
        // arg1.findViewById(R.id.textView1);
        TextView sensorDescription = (TextView) arg1
                .findViewById(R.id.textView2);
        ImageView sensorImage = (ImageView) arg1
                .findViewById(R.id.imageView1);

        locationToggle = (ToggleButton) findViewById(R.id.toggleButton1);
        photosToggle = (ToggleButton) findViewById(R.id.toggleButton1);
        soundToggle = (ToggleButton) findViewById(R.id.toggleButton1);
        orientationToggle = (ToggleButton) findViewById(R.id.toggleButton1);
        messagesToggle = (ToggleButton) findViewById(R.id.toggleButton1);
        batteryToggle = (ToggleButton) findViewById(R.id.toggleButton1);
        calendarToggle = (ToggleButton) findViewById(R.id.toggleButton1);
        accelerometerToggle = (ToggleButton) findViewById(R.id.toggleButton1);
        lightToggle = (ToggleButton) findViewById(R.id.toggleButton1);
        contactsToggle = (ToggleButton) findViewById(R.id.toggleButton1);

        // attach an OnClickListener
        locationToggle.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(context, "CARREGOU", Toast.LENGTH_LONG).show();
                // your click actions go here
            }
        });

        sensorItem sensor = sensorList.get(arg0);

        // sensorName.setText(sensor.sensorName);
        sensorDescription.setText(sensor.sensorDescription);
        sensorImage.setBackground(sensor.sensorImage);

        return arg1;
    }

    public sensorItem getCodeLearnChapter(int position) {
        return sensorList.get(position);
    }

}

你有

setContentView(R.layout.settings);

你说

切换按钮位于列表项.xml文件中

那么这个

locationToggle = (ToggleButton) findViewById(R.id.toggleButton1);

---

失败导致

NullPointerException

ToogleButton

不属于

settings.xml

，您可以在当前视图层次结构中找到视图。

但listitem是设置中listview的一部分。我可以通过R.id.toggleButton1找到它。这没有错@JoaoFilipeClementeMartins为listview和为activity展开的布局不同，您可以在当前视图层次结构下找到视图。因此，如果

settings.xml

没有切换按钮，您会得到任何关于如何在settings.xml中工作的建议？因为这就是我需要的。也许我只是做得不对。@Joaofilpeclementematins你所做的是不可能的。在适配器本身中初始化并写入侦听器there@JoaoFilipeClementeMartins阅读