Android 这些偏好看起来很奇怪？（向右移一点，字体大一点）

我不知道为什么DialogPreference创建的项目的位置会是 向右移动一点，字体大小。。。大一点

我有一个类NumberPickerPreference，它扩展了DialogPreference

package com.example
public class NumberPickerPreference extends DialogPreference{
          ......
}

和pref_general.xml作为首选项

  <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" >
  <PreferenceCategory
    android:title="@string/header_system">

    <!-- extends DialogPreference -->
    <com.example.NumberPickerPreference
        android:key="@string/key_refresh"          
        android:title="@string/title_refresh_time"
        android:dialogTitle="@string/title_refresh_time"
        android:summary="@string/summary_refresh_time"         
        android:negativeButtonText="@string/ui_cancel"
        android:positiveButtonText="@string/ui_ok" />


    <CheckBoxPreference   
        android:title="@string/title_reconnect_unlimit" 
        android:key="@string/key_reconnect_unlimit"
        android:summaryOn="@string/summary_reconnect_unlimit"  
        android:summaryOff="@string/summary_reconnect_unlimit"   
        android:disableDependentsState="true" />

  </PreferenceCategory>
  </PreferenceScreen>

public class SettingsActivity extends Activity {
   @Override
    protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          getFragmentManager().beginTransaction().replace(android.R.id.content, new GeneralPreferenceFragment()).commit();          
    }


    public static class GeneralPreferenceFragment extends PreferenceFragment {
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);                     
            addPreferencesFromResource(R.xml.pref_general);
        }
    }
}