Java 如何在android spinner中添加提示?
我知道有很多问题与我的问题有关,我看过这些解决方案,但无法从中得到帮助。这就是为什么我要发布这个问题 我的Java 如何在android spinner中添加提示?,java,android,json,android-spinner,Java,Android,Json,Android Spinner,我知道有很多问题与我的问题有关,我看过这些解决方案,但无法从中得到帮助。这就是为什么我要发布这个问题 我的app正在从web服务获取json数据。下面是我的json结果 {"users":[{"Id":"1","Name":"Faisal"},{"Id":"2","Name":"Salman"},{"Id":"3","Name":"Asim"},{"Id":"4","Name":"Asad"},{"Id":"5","Name":"Mateen"},{"Id":"6","Name":"Omar"}
app
正在从web服务
获取json
数据。下面是我的json
结果
{"users":[{"Id":"1","Name":"Faisal"},{"Id":"2","Name":"Salman"},{"Id":"3","Name":"Asim"},{"Id":"4","Name":"Asad"},{"Id":"5","Name":"Mateen"},{"Id":"6","Name":"Omar"},{"Id":"7","Name":"Usama"}]}
根据以上数据,我在android spinner中仅显示名称
。下面是我的Config.java
code
public class Config {
//JSON URL
public static final String DATA_URL = "http://10.0.2.2:8000/MobileApp/index.php";
//Tags used in the JSON String
public static final String TAG_NAME = "Name";
public static final String TAG_ID = "Id";
//JSON array name
public static final String JSON_ARRAY = "users";
}
有关MainActivity.java
的信息,请参见下文
public class MainActivity extends AppCompatActivity implements OnItemSelectedListener {
//Declaring an Spinner
private Spinner spinner;
//An ArrayList for Spinner Items
private ArrayList<String> users;
//JSON Array
private JSONArray result;
//TextViews to display details
private TextView textViewResult;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//Initializing the ArrayList
users = new ArrayList<String>();
//Initializing Spinner
spinner = (Spinner)findViewById(R.id.spinner);
//Adding an Item Selected Listener to our Spinner
//As we have implemented the class Spinner.OnItemSelectedListener to this class iteself
// we are passing this to setOnItemSelectedListener
spinner.setOnItemSelectedListener(this);
//Initializing TextView
textViewResult = (TextView)findViewById(R.id.textView);
//This method will fetch the data from the URL
getData();
}
private void getData() {
//Creating a string request
StringRequest stringRequest = new StringRequest(Config.DATA_URL,
new Response.Listener<String>() {
@Override
public void onResponse(String response) {
JSONObject j = null;
try {
//Parsing the fetched Json String to JSON Object
j = new JSONObject(response);
//Storing the Array of JSON String to our JSON Array
result = j.getJSONArray(Config.JSON_ARRAY);
//Calling method getStudents to get the students from the JSON Array
getUsers(result);
} catch (JSONException e) {
e.printStackTrace();
}
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
}
});
//Creating a request queue
RequestQueue requestQueue = Volley.newRequestQueue(this);
//Adding request to the queue
requestQueue.add(stringRequest);
}
private void getUsers(JSONArray j) {
//Traversing through all the items in the json array
for(int i =0; i<j.length(); i++)
{
try
{
//Getting json object
JSONObject json = j.getJSONObject(i);
//Adding the name of the student to array list
users.add(json.getString(Config.TAG_NAME));
} catch (JSONException e) {
e.printStackTrace();
}
}
//Setting adapter to show the items in the spinner
spinner.setAdapter(new ArrayAdapter<String>(MainActivity.this,android.R.layout.simple_spinner_dropdown_item, users));
}
//Method to get student name of a particular position
private String getName(int position)
{
String name = "";
try
{
//Getting object of given index
JSONObject json = result.getJSONObject(position);
//Fetching name from that object
name = json.getString(Config.TAG_NAME);
} catch (JSONException e) {
e.printStackTrace();
}
return name;
}
//Method to get student Id of a particular position
private String getId (int postion)
{
String Id="";
try{
JSONObject json = result.getJSONObject(postion);
Id = json.getString(Config.TAG_ID);
} catch (JSONException e) {
e.printStackTrace();
}
return Id;
}
//this method will execute when we pic an item from the spinner
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
//Appending the values to textview for a selected item
// textViewResult.setText("");
textViewResult.setText("Hi " + getName(position) + " your ID is " + getId(position));
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
textViewResult.setText("");
}
}
当我运行应用程序时,将显示以下结果
根据Selin Marvan K的建议,我有以下几点
//Getting json object
JSONObject json = j.getJSONObject(i);
//Adding the name of the student to array list
users.add("Select a name");
users.add(json.getString(Config.TAG_NAME));
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
//Appending the values to textview for a selected item
// textViewResult.setText("");
if(!getName(position).equals("select a name")) {
textViewResult.setText("Hi " + getName(position-1) + " your ID is " + getId(position-1));
}
//textViewResult.setText("Hi " + getName(position) + " your ID is " + getId(position));
}
public void已选择(AdapterView父视图、视图视图、int位置、长id){
//将选定项的值附加到textview
//textViewResult.setText(“”);
如果(!getName(position).equals(“选择名称”)){
textViewResult.setText(“Hi”+getName(position-1)+“您的ID是”+getId(position-1));
}
//textViewResult.setText(“Hi”+getName(position)+“您的ID是”+getId(position));
}
下面是我看到的结果
它不应该在第一次运行时也在下拉列表中显示文本
它确实显示了我的提示,但结果仍然显示了我的名字和id。当我选择第二个名字时,第三个名字和id将显示出来
我不知道该怎么办。任何帮助都将不胜感激我想斯宾纳没有任何暗示
但我有一个小解决方案
if(!getName(posission).equals("select a name"))
{
textViewResult.setText("Hi " + getName(position-1) + " your ID is " + getId(position-1));
}
public void onItemSelected(AdapterView<?> parent, View view, int position,long id) {
//Appending the values to textview for a selected item
// textViewResult.setText("");
if(!getName(posission).equals("select a name"))
{
textViewResult.setText("Hi " + getName(position-1) + " your ID is " + getId(position-1));
} }
你的代码是
users.add(json.getString(Config.TAG_NAME));//this will add name to user array list
在将用户名添加到arraylist之前,请在下面输入代码
将提示添加到数组中
users.add("your hint");
eg:users.add("select name");
我想它会帮助你使用if条件
if(!getName(posission).equals("select a name"))
{
textViewResult.setText("Hi " + getName(position-1) + " your ID is " + getId(position-1));
}
public void onItemSelected(AdapterView<?> parent, View view, int position,long id) {
//Appending the values to textview for a selected item
// textViewResult.setText("");
if(!getName(posission).equals("select a name"))
{
textViewResult.setText("Hi " + getName(position-1) + " your ID is " + getId(position-1));
} }
在MSelected()函数中
if(!getName(posission).equals("select a name"))
{
textViewResult.setText("Hi " + getName(position-1) + " your ID is " + getId(position-1));
}
public void onItemSelected(AdapterView<?> parent, View view, int position,long id) {
//Appending the values to textview for a selected item
// textViewResult.setText("");
if(!getName(posission).equals("select a name"))
{
textViewResult.setText("Hi " + getName(position-1) + " your ID is " + getId(position-1));
} }
public void已选择(AdapterView父视图、视图视图、int位置、长id){
//将选定项的值附加到textview
//textViewResult.setText(“”);
如果(!getName(posission).equals(“选择名称”))
{
textViewResult.setText(“Hi”+getName(position-1)+“您的ID是”+getId(position-1));
} }
也许这有助于让我知道它是否有效。@SoumyaRauth当然我会马上告诉你的while@SoumyaRauth我无法理解解决方案:(好的,我会尝试让你知道它没有帮助我,它显示了空喷丝头对不起,我的坏,我的xampp
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