java Android Intent不会发送值

Question

我读取数据，然后创建带有两个可能选项的菜单，当选择其中一个时，它会打开新的意图并显示数据。但正如我所见，它并没有传递courseName的价值。问题在于onCreateOptions菜单和onoptionItemSelected方法，因为它们不会从主onCreate方法中获取课程值。你能帮我告诉我怎么修吗

    String courseName = null;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.single_course_layout);

    Intent in = getIntent();
    courseName = in.getStringExtra("fullname");

    TextView label = (TextView)findViewById(R.id.label);
    label.setText(courseName);
    String summary = null;
    TextView summaryContent = (TextView)findViewById(R.id.summary);


    ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
    nameValuePairs.add(new BasicNameValuePair("cname",""+courseName));
    InputStream is = null; 
    String result = null;
    try{
            HttpClient httpclient = new DefaultHttpClient();
            HttpPost httppost = new HttpPost("http://ik.su.lt/~jbarzelis/Bdarbas/getCourseSummary.php");
            httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
            HttpResponse response = httpclient.execute(httppost);
            HttpEntity entity = response.getEntity();
            is = entity.getContent();
    }catch(Exception e){
            Log.e("log_tag", "Error in http connection "+e.toString());
    }
    try{
            BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                    sb.append(line + "\n");
                    System.out.println(line);
            }
            is.close();

            result=sb.toString();
    }catch(Exception e){
            Log.e("log_tag", "Error converting result "+e.toString());
    }

try{
    JSONArray jArray = new JSONArray(result);
    for(int ii=0;ii<jArray.length();ii++){
            JSONObject json_data = jArray.getJSONObject(ii);
            summary = json_data.getString("summary");
     }
    summaryContent.setText(summary);
} catch(JSONException e){
    Log.e("log_tag", "Error parsing data "+e.toString());
}

};

public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.menu, menu);
    return true;
};
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case R.id.users:     

            Intent in = new Intent(getApplicationContext(), AllCourseUsers.class);
            in.putExtra(courseName, "courseName");
            startActivity(in);
            break;

        case R.id.data:     Toast.makeText(this, "You will see data list!", Toast.LENGTH_LONG).show();
                            break;
         }
    return true;
}

Answer 1

你是在把这些价值观倒回去

in.putExtra(courseName, "courseName");

应该是

in.putExtra(key, value);

in.putExtra("courseName", courseName);