嗨,大家好,我正在使用一个应用程序,我想更新我的列表视图,但是一切正常,只有列表视图没有更新,我不明白我在哪里做错了帮助我
代码是
public class MainActivity extends AppCompatActivity implements Spinner.OnItemSelectedListener{
private Spinner spinner;
private ArrayList<String> students;
private JSONArray result;
CallbackManager callbackManager;
ShareDialog shareDialog;
// listveiw data
private static final String TAG = MainActivity.class.getSimpleName();
String url = "http://www.example.com/json/json.php";
private ProgressDialog pDialog;
private List<Model> movieList = new ArrayList<Model>();
private ListView listView;
private CustomListAdapter adapter;
final Model model = new Model();
final Json_Data j_data = new Json_Data();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
FacebookSdk.sdkInitialize(getApplicationContext());
setContentView(R.layout.activity_main);
callbackManager = CallbackManager.Factory.create();
students = new ArrayList<String>();
spinner = (Spinner) findViewById(R.id.txtSpinner);
listView = (ListView) findViewById(R.id.list);
spinner.setOnItemSelectedListener(this);
getData();
listdata();
adapter = new CustomListAdapter(this, movieList);
listView.setAdapter(adapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
final TextView tv_id = (TextView) view.findViewById(R.id.title);
String txt = tv_id.getText().toString();
model.setItemText(txt);
Log.e(TAG, "====>" + txt);
_Dialog_Custom();
}
});
pDialog = new ProgressDialog(this);
pDialog.setMessage("Loading...");
pDialog.show();
}
public void listdata(){
JsonArrayRequest movieReq = new JsonArrayRequest(url,
new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray response) {
hidePDialog();
Log.e(TAG, response.toString());
for (int i = 0; i < response.length(); i++) {
try {
JSONObject obj = response.getJSONObject(i);
Model model = new Model();
String status = obj.getString("txt");
String cate = obj.getString("category");
model.setList_category(cate);
model.setTitle(status);
movieList.add(model);
} catch (JSONException e) {
e.printStackTrace();
}
}
adapter.notifyDataSetChanged();
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d(TAG, "Error: " + error.getMessage());
hidePDialog();
}
});
AppController.getInstance().addToRequestQueue(movieReq);
}
private void getData() {
StringRequest stringRequest = new StringRequest(Config.DATA_URL,
new Response.Listener<String>() {
@Override
public void onResponse(String response) {
JSONObject j_obj = null;
try {
j_obj = new JSONObject(response);
result = j_obj.getJSONArray(Config.JSON_ARRAY);
//Calling method getStudents to get the students from the JSON Array
getStudents(result);
} catch (JSONException e) {
e.printStackTrace();
}
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
}
});
RequestQueue requestQueue = Volley.newRequestQueue(this);
requestQueue.add(stringRequest);
}
private void getStudents(JSONArray j) {
for (int i = 0; i < j.length(); i++) {
try {
JSONObject json = j.getJSONObject(i);
students.add(json.getString(Config.TAG_USERNAME));
} 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, students));
}
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
String text_spinner = spinner.getSelectedItem().toString();
//Log.e("Selected value in","==>"+text_spinner);
j_data.setSpintext(text_spinner);
makeJsonArrayRequest();
Toast.makeText(MainActivity.this, "Get Value from spinner" +text_spinner, Toast.LENGTH_SHORT).show();
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
private void _Dialog_Custom() {
final Dialog dialog = new Dialog(this);
final String txt1 = model.getItemText().toString();
Log.e("Hello Dialog", ":=>" + txt1);
dialog.setContentView(R.layout.dialogbox);
dialog.setTitle("Share via");
dialog.setCanceledOnTouchOutside(true);
ImageButton _Fb_Sharebtn = (ImageButton) dialog.findViewById(R.id.share_facebook);
_Fb_Sharebtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (ShareDialog.canShow(ShareLinkContent.class)) {
// https://developers.facebook.com/docs/sharing/android
ShareLinkContent linkContent = new ShareLinkContent.Builder()
.setContentTitle("Hello Facebook")
.setContentDescription(
"The 'Hello Facebook' sample showcases simple Facebook integration")
.setContentUrl(Uri.parse("http://developers.facebook.com/android"))
.build();
shareDialog.show(linkContent);
}
}
});
ImageButton _Sharebtn_google = (ImageButton) dialog.findViewById(R.id.share_btn_google);
_Sharebtn_google.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent shareIntent = new PlusShare.Builder(MainActivity.this)
.setType("text/plain")
.setText(txt1)
.getIntent();
try {
startActivity(shareIntent);
} catch (ActivityNotFoundException ex) {
startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("https://play.google.com/store/apps/details?id=com.google.android.apps.plus&hl=en")));
}
}
});
ImageButton whtsapp_sahre = (ImageButton) dialog.findViewById(R.id.whatsapp_btn);
whtsapp_sahre.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent whatsappIntent = new Intent(Intent.ACTION_SEND);
whatsappIntent.setType("text/plain");
whatsappIntent.setPackage("com.whatsapp");
String result = txt1;
whatsappIntent.putExtra(Intent.EXTRA_TEXT, result);
try {
startActivity(whatsappIntent);
} catch (ActivityNotFoundException ex) {
startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("https://play.google.com/store/apps/details?id=com.whatsapp")));
}
}
});
ImageButton _Twwiterbtn = (ImageButton) dialog.findViewById(R.id.twwiter_btn);
_Twwiterbtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(Intent.ACTION_SEND);
String result = txt1;
intent.setType("text/plain")
.setPackage("com.twitter.android");
intent.putExtra(Intent.EXTRA_TEXT, result);
try {
startActivity(intent);
} catch (ActivityNotFoundException ex) {
startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("https://play.google.com/store/apps/details?id=com.twitter.android&hl=en")));
}
}
});
dialog.setOnCancelListener(new DialogInterface.OnCancelListener() {
@Override
public void onCancel(DialogInterface dialog) {
}
});
dialog.setOnDismissListener(new DialogInterface.OnDismissListener() {
@Override
public void onDismiss(DialogInterface dialog) {
}
});
dialog.show();
}
protected void onActivityResult(final int requestCode, final int resultCode, final Intent data) {
super.onActivityResult(requestCode, resultCode, data);
callbackManager.onActivityResult(requestCode, resultCode, data);
}
@Override
public void onBackPressed() {
super.onBackPressed();
Intent backintent = new Intent(getApplicationContext(), Main_Selected_Activity.class);
startActivity(backintent);
finish();
}
@Override
public void onDestroy() {
super.onDestroy();
hidePDialog();
}
private void hidePDialog() {
if (pDialog != null) {
pDialog.dismiss();
pDialog = null;
}
}
private void makeJsonArrayRequest() {
String spinner_data =j_data.getSpintext().toString().trim();
Log.e(TAG, spinner_data.toString());
String arrayurl = "http://www.example.com/jsoncategory.php?category="+spinner_data;
Log.e("Link is here","==>"+arrayurl);
ArrayList<String> newdata = new ArrayList<String>();
movieList = new ArrayList<Model>();
JsonArrayRequest movieReq = new JsonArrayRequest(arrayurl,
new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray response) {
Log.e(TAG, "link response=>" + response);
for (int i = 0; i < response.length(); i++) {
try {
JSONObject obj = response.getJSONObject(i);
String name = obj.getString("txt");
model.setList_category(name);
movieList.add(model);
}catch (JSONException e) {
e.printStackTrace();
Log.e("Hello error","==>"+e);
}
}
adapter.notifyDataSetChanged();
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d(TAG, "Error: " + error.getMessage());
hidePDialog();
}
});
AppController.getInstance().addToRequestQueue(movieReq);
}
}
请帮我
最佳答案
采用movieList.clear();
代替movieList = new ArrayList<Model>();
问题是关于创建新的数组列表。因此,当您要创建一个新的ArrayList(具有不同的地址)时,ArrayAdapter不会“知道”您。
排队adapter = new CustomListAdapter(this, movieList);
你推一些arraylist的地址。稍后在新的一行中,您将生成一个具有不同列表的新arraylist并对其进行处理。但是适配器可以与arraylist的“旧版本”一起使用。