用 JSON 填充 Spinner

Question

我发现了这个很棒的 JSON 为 Android 解析 tutorial 并且因为我对这个领域还很陌生，我想问一下如何用给定的数据。当用户单击名称时，其余名称将加载，然后当用户再次选择一个名称时，它必须保持活动状态。任何帮助将不胜感激！！！

public class MainActivity extends Activity {

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

        // we will using AsyncTask during parsing
        new AsyncTaskParseJson().execute();
    }

    // you can make this class as another java file so it will be separated from your main activity.
    public class AsyncTaskParseJson extends AsyncTask<String, String, String> {

        final String TAG = "AsyncTaskParseJson.java";

        // set your json string url here
        String yourJsonStringUrl = "http://demo.codeofaninja.com/tutorials/json-example-with-php/index.php";

        // contacts JSONArray
        JSONArray dataJsonArr = null;

        @Override
        protected void onPreExecute() {}

        @Override
        protected String doInBackground(String... arg0) {

            try {

                // instantiate our json parser
                JsonParser jParser = new JsonParser();

                // get json string from url
                JSONObject json = jParser.getJSONFromUrl(yourJsonStringUrl);

                // get the array of users
                dataJsonArr = json.getJSONArray("Users");

                // loop through all users
                for (int i = 0; i < dataJsonArr.length(); i++) {

                    JSONObject c = dataJsonArr.getJSONObject(i);

                    // Storing each json item in variable
                    String firstname = c.getString("firstname");
                    String lastname = c.getString("lastname");
                    String username = c.getString("username");

                    // show the values in our logcat
                    Log.e(TAG, "firstname: " + firstname
                            + ", lastname: " + lastname
                            + ", username: " + username);

                }

            } catch (JSONException e) {
                e.printStackTrace();
            }

            return null;
        }

        @Override
        protected void onPostExecute(String strFromDoInBg) {}
    }
}

Answer 1

从 json 创建列表，这样

List<String> list = new ArrayList<String>();
list.add(json element);
list.add(json element);
list.add(json element);


ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this,
    android.R.layout.simple_spinner_item, list);
spinner.setAdapter(dataAdapter);

Answer 2

Spinner 使用列表对象来提供数据。所以你应该有一个 Spinner 对象的支持列表。

在 for 循环之前，执行以下操作：

List<String> namesList = new ArrayList<String>();

然后在您的 for 循环中，将名称添加到此列表中：

//I'm assuming you are going to display only the first name
namesList.add(firstName);

然后创建一个将列表绑定到 Spinner 的 ArrayAdapter 对象。

ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, namesList);
yourSpinner.setAdapter(adapter);

Answer 3

感谢大家的帮助，但真正的解决方案在于需要在 OnPostExecute() 中添加以下代码：

Spinner yourSpinner= (Spinner) findViewById(R.id.yourSpinner);

ArrayAdapter<String> adapter = new ArrayAdapter<String>(<YourActivityNAme>.this, android.R.layout.simple_spinner_item, namesList);
yourSpinner.setAdapter(adapter);

用 JSON 填充 Spinner

Populate Spinner with JSON

android

json

spinner