这是我的代码，我非常努力地在微调器中显示项目，但一切都是徒劳的列表显示时按微调箭头但不选择并且不显示在 Toast 中，所以请帮助我并指导我错在哪里
public class MakeComplain extends AppCompatActivity implements
OnItemSelectedListener {
private Spinner spinner,spinner1,spinner3;
private TextView txtCategory;
private ArrayList<String> Station;
private JSONArray result;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_make_complain);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
spinner1 = (Spinner) findViewById(R.id.station);
spinner3 = (Spinner) findViewById(R.id.generator);
spinner = (Spinner) findViewById(R.id.complain);
spinner1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
//Get data from the list which you had set to the adapter of spinner1
Toast.makeText(MakeComplain.this, "Spinner1 Item Clicked: "+position, Toast.LENGTH_SHORT).show();
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
spinner3.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
//Get data from the list which you had set to the adapter of spinner3
Toast.makeText(MakeComplain.this, "Spinner3 Item Clicked: "+position, Toast.LENGTH_SHORT).show();
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
ArrayAdapter arrayAdapter = ArrayAdapter.createFromResource(this, R.array.Complain, android.R.layout.simple_spinner_item);
spinner.setAdapter(arrayAdapter);
spinner1.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, this.fetchTwitterPublicTimeline()));
spinner3.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, this.fetchGeneratorList()));
}
public ArrayList<String> fetchTwitterPublicTimeline()
{
final ArrayList<String> listItems = new ArrayList<String>();
new Thread(new Runnable() {
@Override
public void run() {
try {
URL url = new URL("http://bigbi.com/cs/Station.php");
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
//urlConnection.setRequestProperty("User-Agent", "Mozilla/5.0");
InputStream stream = urlConnection.getInputStream();
InputStreamReader reader = new InputStreamReader(stream);
BufferedReader bufferedReader = new BufferedReader(reader);
String line;
while ((line = bufferedReader.readLine()) != null) {
JSONArray ja = new JSONArray(line);
for (int i = 0; i < ja.length(); i++) {
JSONObject jo = (JSONObject) ja.get(i);
listItems.add(jo.getString("name"));
}
}
bufferedReader.close();
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}).start();
return listItems;
}
public ArrayList<String> fetchGeneratorList()
{
final ArrayList<String> listItems = new ArrayList<String>();
new Thread(new Runnable() {
@Override
public void run() {
try {
URL url = new URL("http://biges.com/12/get.php");
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
//urlConnection.setRequestProperty("User-Agent", "Mozilla/5.0");
InputStream stream = urlConnection.getInputStream();
InputStreamReader reader = new InputStreamReader(stream);
BufferedReader bufferedReader = new BufferedReader(reader);
String line;
while ((line = bufferedReader.readLine()) != null) {
JSONArray ja = new JSONArray(line);
for (int i = 0; i < ja.length(); i++) {
JSONObject jo = (JSONObject) ja.get(i);
listItems.add(jo.getString("gen_no"));
}
}
bufferedReader.close();
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}).start();
return listItems;
}
public void onItemSelected(AdapterView<?> parent, View view, int position,
long id) {
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
}
}
请尝试这个，
spinner1.setAdapter(new ArrayAdapter<String>(this, R.layout.spinner_item, fetchTwitterPublicTimeline()));
spinner3.setAdapter(new ArrayAdapter<String>(this, R.layout.spinner_item,fetchGeneratorList()));
单击项目可以添加。
public void onItemSelected(AdapterView<?> parent, View view, int position,
long id) {
Toast.makeText(getActivity(), "Item clicked",
Toast.LENGTH_LONG).show();
}
你错过了两件事。
-
您尚未添加用于选择项目的侦听器。添加以下内容以添加侦听器。
spinner.setOnItemSelectedListener(this);如果需要，可以为其他微调器添加相同的内容。
-
添加用于在方法中显示 toast 的代码
onItemSelected()。像这样的东西Toast.makeText(this, "Item Clicked", Toast.LENGTH_SHORT).show();
您已经为微调器实现了 onItemSelect 的侦听器，但您没有将 onItemSelect 设置为微调器，因此请像这样更新您的 onCreate：
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_make_complain);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
spinner1 = (Spinner) findViewById(R.id.station);
spinner3 = (Spinner) findViewById(R.id.generator);
spinner = (Spinner) findViewById(R.id.complain);
spinner1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
//Get data from the list which you had set to the adapter of spinner1
Toast.makeText(this, "Spinner1 Item Clicked: "+position, Toast.LENGTH_SHORT).show();
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
spinner3.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
//Get data from the list which you had set to the adapter of spinner3
Toast.makeText(this, "Spinner3 Item Clicked: "+position, Toast.LENGTH_SHORT).show();
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
//Get data from the list which you had set to the adapter of spinner
Toast.makeText(this, "Spinner Item Clicked: "+position, Toast.LENGTH_SHORT).show();
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
ArrayAdapter arrayAdapter = ArrayAdapter.createFromResource(this, R.array.Complain, android.R.layout.simple_spinner_item);
spinner.setAdapter(arrayAdapter);
Station=this.fetchTwitterPublicTimeline();
spinner1.setAdapter(new ArrayAdapter<String>(this, R.layout.spinner_item,R.id.txt, this.fetchTwitterPublicTimeline()));
spinner3.setAdapter(new ArrayAdapter<String>(this, R.layout.spinner_item,R.id.txt, this.fetchGeneratorList()));
}
我单独在这里将 setOnItemSelectedListener 设置为微调器，因为如果我们像您一样覆盖一种方法，那么您将无法找出哪些微调器项目选择是回调。
因此，为此删除实现的
实现 OnItemSelectedListener 来自您的活动，相对而言，它也被覆盖了方法，并按照我的回答进行操作。