我想从doInBackground发送3个字符串到onPostExecute。
我设法获取数据,我可以在日志中看到它们。现在,一旦doInBackground完成执行,如何使用存储在Strings中的数据。
这是我的代码。
public class MainActivity extends AppCompatActivity {
private ProgressDialog pDialog;
// URL to get contacts JSON
private static String url = "http://example.com/test.php";
// JSON Node names
private static final String tag_info = "info";
private static final String tag_success = "Success";
private static final String tag_message = "message";
private static final String tag_output = "output";
// contacts JSONArray
JSONArray info = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Calling async task to get json
new fetchInfo().execute();
}
/**
* Async task class to get json by making HTTP call
* */
private class fetchInfo extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(MainActivity.this);
pDialog.setMessage("Please wait...");
pDialog.setCancelable(false);
pDialog.show();
}
@Override
protected Void doInBackground(Void... arg0) {
// Creating service handler class instance
ServiceHandler sh = new ServiceHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url, ServiceHandler.GET);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
info = jsonObj.getJSONArray(tag_info);
JSONObject c = info.getJSONObject(0);
// I want to use these 3 strings in onPostExecute
String success = c.getString(tag_success);
String message = c.getString(tag_message);
String output = c.getString(tag_output);
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
TextView successView = (TextView) findViewById(R.id.success_field);
successView.setText(success + " " + message + " " + output); // I want to print them here
}
}
}
答案 0 :(得分:1)
使用字符串数组
protected String[] doInBackground(String[]... passing) {
String[] result = new String[3];
result[0]= c.getString(tag_success);
result[1] = c.getString(tag_message);
result[2] = c.getString(tag_output);
return result; //return result
}
protected void onPostExecute(String result[]) {
String a = result[0];
}
答案 1 :(得分:0)
public class fetchInfo extends AsyncTask<Void, Void, String> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(MainActivity.this);
pDialog.setMessage("Please wait...");
pDialog.setCancelable(false);
pDialog.show();
}
@Override
protected String doInBackground(Void... params) {
ServiceHandler sh = new ServiceHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url, ServiceHandler.GET);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
info = jsonObj.getJSONArray(tag_info);
JSONObject c = info.getJSONObject(0);
// I want to use these 3 strings in onPostExecute
String success = c.getString(tag_success);
String message = c.getString(tag_message);
String output = c.getString(tag_output);
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
return output;
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
if (pDialog.isShowing())
pDialog.dismiss();
TextView successView = (TextView) findViewById(R.id.success_field);
successView.setText(s); // I want to print them here
}
}
答案 2 :(得分:0)
Bean类
public class BeanClass{
String message,success,output;
public BeanClass(String message,String success,String output){
this.message = message;
this.success = success;
this.output = output;
}
public String getMessage(){ return message;}
public String getSuccess(){ return success;}
public String getOutput(){ return output;}
}
将您的异步任务更改为
private class fetchInfo extends AsyncTask<Void, Void, BeanClass> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(MainActivity.this);
pDialog.setMessage("Please wait...");
pDialog.setCancelable(false);
pDialog.show();
}
@Override
protected Bean doInBackground(Void... arg0) {
// Creating service handler class instance
Bean result=null;
ServiceHandler sh = new ServiceHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url, ServiceHandler.GET);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
info = jsonObj.getJSONArray(tag_info);
JSONObject c = info.getJSONObject(0);
// I want to use these 3 strings in onPostExecute
String success = c.getString(tag_success);
String message = c.getString(tag_message);
String output = c.getString(tag_output);
result = new Bean(sucess,message,output);
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
return result;
}
@Override
protected void onPostExecute(Bean result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
if(result!=null){
TextView successView = (TextView) findViewById(R.id.success_field);
successView.setText(result.getSuccess() + " " + result.getMessage() + " " + result.getOutput()); // I want to print them here
}
}
}
答案 3 :(得分:0)
在声明
时执行此操作Public class Do Task extends AsyncTask<Void, Void, String>{
然后在doInBackground方法
protected String[] doInBackground(String[]... passing) {
return result; //change it to a string from null
}
然后在onPostExecute结果是你想要的字符串
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
}
如果您仍然遇到问题,请告诉我。如果有帮助,请告知我们。
答案 4 :(得分:0)
试试这个.......不需要传递
public class MainActivity extends AppCompatActivity {
private ProgressDialog pDialog;
// URL to get contacts JSON
private static String url = "http://example.com/test.php";
// JSON Node names
private static final String tag_info = "info";
private static final String tag_success = "Success";
private static final String tag_message = "message";
private static final String tag_output = "output";
// contacts JSONArray
JSONArray info = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Calling async task to get json
new fetchInfo().execute();
}
/**
* Async task class to get json by making HTTP call
* */
private class fetchInfo extends AsyncTask<Void, Void, Void> {
String success = "";
String message = "";
String output = "";
@Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(MainActivity.this);
pDialog.setMessage("Please wait...");
pDialog.setCancelable(false);
pDialog.show();
}
@Override
protected Void doInBackground(Void... arg0) {
// Creating service handler class instance
ServiceHandler sh = new ServiceHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url, ServiceHandler.GET);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
info = jsonObj.getJSONArray(tag_info);
JSONObject c = info.getJSONObject(0);
// I want to use these 3 strings in onPostExecute
success = c.getString(tag_success);
message = c.getString(tag_message);
output = c.getString(tag_output);
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
TextView successView = (TextView) findViewById(R.id.success_field);
successView.setText(success + " " + message + " " + output); // I want to print them here
Log.e("First Value", success);
Log.e("Second Value", message);
Log.e("Third Value", output);
}
}
}