[英]How to make a toast when parsing data from json is null or no result?
當我的表數據庫基於解析json為空時,我會舉杯敬酒。 我的意思是,當沒有結果或找不到數據時,敬酒“對不起,找不到數據”。 任何幫助將不勝感激。
這是我用於顯示數據的代碼
private void showEmployee(){
JSONObject jsonObject = null;
ArrayList<HashMap<String,String>> list = new ArrayList<HashMap<String, String>>();
try {
jsonObject = new JSONObject(JSON_STRING);
JSONArray result = jsonObject.getJSONArray(konfigurasi.TAG_JSON_ARRAY);
for(int i = 0; i<result.length(); i++){
JSONObject jo = result.getJSONObject(i);
String id = jo.getString(konfigurasi.TAG_ID);
String nama = jo.getString(konfigurasi.TAG_NAMA);
String pyg = jo.getString(konfigurasi.TAG_PENYELENGGARA);
String tmpt = jo.getString(konfigurasi.TAG_TEMPAT);
String tgl = jo.getString(konfigurasi.TAG_TGL);
String jam = jo.getString(konfigurasi.TAG_JAM);
String email = jo.getString(konfigurasi.TAG_EMAIL);
HashMap<String,String> employees = new HashMap<>();
employees.put(konfigurasi.TAG_ID,id);
employees.put(konfigurasi.TAG_NAMA,nama);
employees.put(konfigurasi.TAG_PENYELENGGARA,pyg);
employees.put(konfigurasi.TAG_TEMPAT,tmpt);
employees.put(konfigurasi.TAG_TGL,tgl);
employees.put(konfigurasi.TAG_JAM,jam);
employees.put(konfigurasi.TAG_EMAIL,email);
list.add(employees);
}
} catch (JSONException e) {
e.printStackTrace();
}
ListAdapter adapter = new MySimpleArrayAdapter(this, list);
listView.setAdapter(adapter);
}
這是postexcetude代碼:
private void getJSON(){
class GetJSON extends AsyncTask<Void,Void,String>{
ProgressDialog loading;
@Override
protected void onPreExecute() {
super.onPreExecute();
loading = ProgressDialog.show(TampilSemuaPgw.this,"Mengambil Data","Mohon Tunggu...",false,false);
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
if(s == null || s.length() == 0){
Toast.makeText(getApplicationContext(), "No Data",Toast.LENGTH_LONG).show();
}
// Dismiss the progress dialog
if (loading.isShowing())
loading.dismiss();
JSON_STRING = s;
showEmployee();
}
@Override
protected String doInBackground(Void... params) {
RequestHandler rh = new RequestHandler();
String s = rh.sendGetRequest(konfigurasi.URL_GET_ALL);
return s;
}
}
GetJSON gj = new GetJSON();
gj.execute();
}
KeLiuyue的更新代碼 :
@Override
protected String doInBackground(Void... params) {
RequestHandler rh = new RequestHandler();
String s = rh.sendGetRequest(konfigurasi.URL_GET_ALL);
return s;
}
@Override
protected void onPostExecute(String s) {
try {
JSONObject jsonObject = new JSONObject(s);
JSONArray jsonArray = jsonObject.getJSONArray("result");
if(jsonArray.length() == 0){
Toast.makeText(getApplicationContext(), "No Data", Toast.LENGTH_LONG).show();
if (loading.isShowing()){
loading.dismiss();
}
return;
}
} catch (JSONException e) {
e.printStackTrace();
}
Log.e("TAG",s);
// Dismiss the progress dialog
if (loading.isShowing())
loading.dismiss();
JSON_STRING = s;
showEmployee();
}
在您的代碼中嘗試一下。
@Override
protected String doInBackground(Void... params) {
RequestHandler rh = new RequestHandler();
String s = rh.sendGetRequest(konfigurasi.URL_GET_ALL);
return s;
}
@Override
protected void onPostExecute(String s) {
// edited here
try {
JSONObject jsonObject = new JSONObject(s);
JSONArray jsonArray = jsonObject.getJSONArray("result");
if(jsonArray.length() == 0){
Toast.makeText(getApplicationContext(), "No Data", Toast.LENGTH_LONG).show();
if (loading.isShowing()){
loading.dismiss();
}
return;
}
} catch (JSONException e) {
e.printStackTrace();
}
Log.e("TAG",s);
// Dismiss the progress dialog
if (loading.isShowing())
loading.dismiss();
JSON_STRING = s;
showEmployee();
}
1.在doInBackground
方法中確定返回值是否為空
2.在onPostExecute
方法中確定參數值是否為空
您需要調試此問題,為什么您的吐司不顯示:
您已正確將show Toast代碼放入onPostExecute
現在進行調試,首先放置一個Log來知道s的值,無論它是null還是空。
如果是,仍然沒有顯示Toast,請在Toast之前將對話框關閉對話框移開並進行檢查。
如果Toast仍然不顯示調試調試showEmployee()方法的功能。
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