我正在尝试在我的代码中实现 SharedPreferences,它存储图像文件名。
这是我用来实现 SharedPreferences 的代码 -
private void setpath(String path2) {
// TODO Auto-generated method stub
System.out.println("sharedpreferences "+path2);
try{
SharedPreferences settings = getSharedPreferences(PREFS_NAME,0); //I am getting NullPointerException here.
SharedPreferences.Editor editor = settings.edit();
editor.putString("name",path2);
Log.v("path in setpath of MyFileOberver : ",path2);
editor.commit();
Intent i=new Intent(getApplicationContext(),ArrAdapter.class);
i.putExtra("path", path);
startActivity(i);
}
catch(Exception e)
{
Log.v("Exception in SharedPreferences : ",e.toString());
}
}
ArrAdapter.java:
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.fileeventlist);
info = new adapter(this);
listView = (ListView) findViewById(android.R.id.list);
setContentView(R.layout.fileeventlist);
SharedPreferences settings = getSharedPreferences (PREFS_NAME,0);
String newpath = "newpath";
this.path = settings.getString("name",newpath);
Log.v("New path in FileEvent : ",newpath);
}
logcat 显示以下消息 -
09-27 11:07:14.141: A/FileObserver(14481): Unhandled exception in FileObserver com.example.sample_fileobserver.MyFileObserver@b1178718
09-27 11:07:14.141: A/FileObserver(14481): java.lang.NullPointerException
09-27 11:07:14.141: A/FileObserver(14481): at android.content.ContextWrapper.getSharedPreferences(ContextWrapper.java:167)
09-27 11:07:14.141: A/FileObserver(14481): at com.example.sample_fileobserver.FileEvent.setpath(FileEvent.java:135)
我无法理解,我的代码哪里出错了。
提前致谢。