选择状态后，使用notifyDataSetChanged更新City Spinner [英] Update City Spinner with notifyDataSetChanged after state is selected
本文介绍了选择状态后，使用notifyDataSetChanged更新City Spinner的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
用户选择状态后如何更新我的城市微调器？
这两个字段都使用 JSON 数据并将信息解析为微调器的数组。
Both fields are populated using a DataCall.class that returns JSON data and parses the info into an array for the spinner.
我的代码将城市 adapter 设置为defualt Select State值，一旦用户获得它应该使用的状态notifyDataSetChanged，因为使用新城市名称更新了城市微调器的默认数组。我收到的错误在下面的代码中得到了注释。
My code below sets the city adapter to a defualt "Select State" value and once the user gets selects the state it should use notifyDataSetChanged since the default array for the city spinner is updated with the new city names. The errors I am getting are commented in my code below.
public class SearchActivity extends Activity{
private static final String TAG = "MyApp";
ArrayAdapter<String> adapter2;
String city_values[] = new String[]{"Please select a state."};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.search_layout);
final Spinner zipspinner = (Spinner) findViewById(R.id.zipspinner);
final Spinner cityspinner = (Spinner) findViewById(R.id.cityspinner);
adapter2 = new ArrayAdapter<String> (this,android.R.layout.simple_spinner_item, city_values);
adapter2.setDropDownViewResource(R.layout.city_spinner_layout);
cityspinner.setAdapter(adapter2);
JSONArray jsonArray;
try {
String spinnerContentType = "state";
String spinnerURL = "getStoreState.php";
String spinner_data = DataCall.getJSON(spinnerURL,spinnerContentType);
Log.d(TAG, spinner_data);
jsonArray = new JSONArray(spinner_data);
final String[] array_spinner = new String[jsonArray.length()];
for (int i=0; i<jsonArray.length(); i++) {
String styleValue = jsonArray.getJSONArray(i).getString(0);
Log.d(TAG, styleValue);
array_spinner[i] = styleValue;
}
ArrayAdapter<String> adapter = new ArrayAdapter<String> (this,
android.R.layout.simple_spinner_item,array_spinner);
adapter.setDropDownViewResource(R.layout.state_spinner_layout);
zipspinner.setAdapter(adapter);
zipspinner.setOnItemSelectedListener(new OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> parent,View view, int pos, long id) {
int item = zipspinner.getSelectedItemPosition();
if(item != 0){
String item_value = array_spinner[item];
String spinnerContentType = "city";
String spinnerURL = "getStoreCity.php?state=" + item_value;
Log.d(TAG, spinnerURL);
String city_data = DataCall.getJSON(spinnerURL,spinnerContentType);
Log.d(TAG, city_data);
JSONArray cityArray = null;
try {
cityArray = new JSONArray(city_data);
} catch (JSONException e) {
e.printStackTrace();
}
final String[] city_spinner = new String[cityArray.length()];
for (int i=0; i<cityArray.length(); i++){
String styleValue = null;
try {
styleValue = cityArray.getJSONArray(i).getString(0);
Log.d(TAG, styleValue);
} catch (JSONException e) {
e.printStackTrace();
}
city_spinner[i] = styleValue;
}
city_values = city_spinner;
adapter2.notifyDataSetChanged();
String test_string = "NOTIFY UPDATE";
Log.d(TAG, test_string);
} else {
// finish();
}
}
public void onNothingSelected(AdapterView parent) {
// Do nothing.
}
});
cityspinner.setOnItemSelectedListener(new OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> parent,View view, int pos, long id) {
int item = zipspinner.getSelectedItemPosition();
if(item != 0){
}else{
}
}
public void onNothingSelected(AdapterView parent) {
// Do nothing.
}
});
}catch (JSONException e) {
e.printStackTrace();
}
}
}
推荐答案
public class SearchActivity extends Activity {
ArrayAdapter<String> adapter2;
String city_values[];
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.search_layout);
final Spinner zipspinner = (Spinner) findViewById(R.id.zipspinner);
final Spinner cityspinner = (Spinner) findViewById(R.id.cityspinner);
String city_values[] = new String[]{"Please select a state."};
adapter2 = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, city_values);
adapter2.setDropDownViewResource(R.layout.city_spinner_layout);
cityspinner.setAdapter(adapter2);
JSONArray jsonArray;
final JSONArray cityArray;
try {
String spinnerContentType = "state";
String spinnerURL = "getStoreState.php";
String spinner_data = DataCall.getJSON(spinnerURL, spinnerContentType);
jsonArray = new JSONArray(spinner_data);
final String[] array_spinner = new String[jsonArray.length()];
for (int i = 0; i < jsonArray.length(); i++) {
String styleValue = jsonArray.getJSONArray(i).getString(0);
array_spinner[i] = styleValue;
}
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, array_spinner);
adapter.setDropDownViewResource(R.layout.state_spinner_layout);
zipspinner.setAdapter(adapter);
zipspinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
int item = zipspinner.getSelectedItemPosition();
String item_value = array_spinner[item];
String spinnerContentType = "city";
String spinnerURL = "getStoreCity.php?state=" + item_value;
String city_data = DataCall.getJSON(spinnerURL, spinnerContentType);
cityArray = new JSONArray(city_data); //The final local variable cityArray cannot be assigned, since it is defined in an enclosing type
final String[] city_spinner = new String[cityArray.length()];
for (int i = 0; i < cityArray.length(); i++) {
String styleValue = cityArray.getJSONArray(i).getString(0); //Unhandled exception type JSONException
city_spinner[i] = styleValue;
}
city_values = city_spinner; //Unhandled exception type JSONException
adapter2.notifyDataSetChanged();
}
public void onNothingSelected(AdapterView parent {
// Do nothing.
}
});
} catch (JSONException e) {
e.printStackTrace();
}
}
}
现在尝试
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