[英]Update City Spinner with notifyDataSetChanged after state is selected
用户选择州后,如何更新我的城市微调器?
这两个字段都是使用DataCall.class
填充的, DataCall.class
返回JSON
数据并将信息解析为微调器的数组。
我下面的代码将城市adapter
设置为默认的“选择州”值,并且一旦用户选择了州,则应使用notifyDataSetChanged,因为城市微调器的默认数组已使用新的城市名称进行了更新。 我在下面的代码中注释了我遇到的错误。
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();
}
}
}
好吧,这就是我的建议,
首先,检查您是否在city_values
中获取值。 然后,通知适配器。... adapter2.notifyDataSetChanged();
最后是cityspinner.setSelection(0);
UPDATE:
我建议用ArrayList<String> instead of String[]
谢谢...
在分配new JSONArray()
的地方声明city_array
变量。 无论如何,您都是暂时使用它。 只需再次设置适配器。
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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