填充微调使用JSON [英] Populating Spinner with JSON
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问题描述
我做了微调填充与JSON.But我得到一个错误的ArrayList中：世界人口不能得到解决。
I done a populating spinner with JSON.But I got a Error in ArrayList: WorldPopulation cannot be resolved.
public class MainActivity extends Activity {
JSONObject jsonobject;
JSONArray jsonarray;
ProgressDialog mProgressDialog;
ArrayList<String> worldlist;
ArrayList<WorldPopulation> world;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
new DownloadJSON().execute();
}
private class DownloadJSON extends AsyncTask<Void, Void, Void> {
@Override
protected Void doInBackground(Void... params) {
world = new ArrayList<WorldPopulation>();
worldlist = new ArrayList<String>();
jsonobject = JSONfunctions
.getJSONfromURL("http://www.androidbegin.com/tutorial/jsonparsetutorial.txt"); //JSON Functions cannot be resolved Error occured
try {
jsonarray = jsonobject.getJSONArray("worldpopulation");
for (int i = 0; i < jsonarray.length(); i++) {
jsonobject = jsonarray.getJSONObject(i);
WorldPopulation worldpop = new WorldPopulation();
worldpop.setRank(jsonobject.optString("rank"));
worldpop.setCountry(jsonobject.optString("country"));
worldpop.setPopulation(jsonobject.optString("population"));
worldpop.setFlag(jsonobject.optString("flag"));
world.add(worldpop);
worldlist.add(jsonobject.optString("country"));
}
} catch (Exception e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void args) {
Spinner mySpinner = (Spinner) findViewById(R.id.my_spinner);
mySpinner
.setAdapter(new ArrayAdapter<String>(MainActivity.this,
android.R.layout.simple_spinner_dropdown_item,
worldlist));
mySpinner
.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> arg0,
View arg1, int position, long arg3) {
TextView txtrank = (TextView) findViewById(R.id.rank);
TextView txtcountry = (TextView) findViewById(R.id.country);
TextView txtpopulation = (TextView) findViewById(R.id.population);
txtrank.setText("Rank : "
+ world.get(position).getRank());
txtcountry.setText("Country : "
+ world.get(position).getCountry());
txtpopulation.setText("Population : "
+ world.get(position).getPopulation());
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
}
});
}
}
}
这是同类型的ArrayList误差在code.In XML编码发生的一切多行是fine.Anybody告诉我怎么解决这个问题。
That Same kind of ArrayList error occured many lines in a code.In xml Coding Everything was fine.Anybody tell me how to solve it.
推荐答案
从链接张贴它看起来像一个不完整的教程。
From the link posted it looks like a incomplete tutorial.
//JSON Functions cannot be resolved Error occured
所以这本手册是缺少 JSONFunctions 类和世界人口类。
有以下并保持$ C $其余相同c。
Have the below and keep the rest of the code the same.
private class DownloadJSON extends AsyncTask<Void, Void, Void> {
{
@Override
protected Void doInBackground(Void... params) {
world = new ArrayList<WorldPopulation>();
worldlist = new ArrayList<String>();
try
{
HttpClient httpclient = new DefaultHttpClient();
httpclient.getParams().setParameter(CoreProtocolPNames.PROTOCOL_VERSION, HttpVersion.HTTP_1_1);
HttpGet request = new HttpGet("http://www.androidbegin.com/tutorial/jsonparsetutorial.txt");
HttpResponse response = httpclient.execute(request);
HttpEntity resEntity = response.getEntity();
String _response=EntityUtils.toString(resEntity);
Log.i("Response is......................",""+_response);
jsonobject = new JSONObject(_response);
jsonarray = jsonobject.getJSONArray("worldpopulation");
for (int i = 0; i < jsonarray.length(); i++) {
jsonobject = jsonarray.getJSONObject(i);
WorldPopulation worldpop = new WorldPopulation();
worldpop.setRank(jsonobject.optString("rank"));
worldpop.setCountry(jsonobject.optString("country"));
worldpop.setPopulation(jsonobject.optString("population"));
worldpop.setFlag(jsonobject.optString("flag"));
world.add(worldpop);
worldlist.add(jsonobject.optString("country"));
}catch(Exception e)
{
}
return null;
}
编辑：
public class MainActivity extends Activity {
JSONObject jsonobject;
JSONArray jsonarray;
ProgressDialog mProgressDialog;
ArrayList<String> worldlist;
ArrayList<WorldPopulation> world;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
new DownloadJSON().execute();
}
private class DownloadJSON extends AsyncTask<Void, Void, Void>
{
@Override
protected Void doInBackground(Void... params) {
world = new ArrayList<WorldPopulation>();
worldlist = new ArrayList<String>();
try
{
HttpClient httpclient = new DefaultHttpClient();
httpclient.getParams().setParameter(CoreProtocolPNames.PROTOCOL_VERSION, HttpVersion.HTTP_1_1);
HttpGet request = new HttpGet("http://www.androidbegin.com/tutorial/jsonparsetutorial.txt");
HttpResponse response = httpclient.execute(request);
HttpEntity resEntity = response.getEntity();
String _response=EntityUtils.toString(resEntity);
Log.i("Response is......................",""+_response);
jsonobject = new JSONObject(_response);
jsonarray = jsonobject.getJSONArray("worldpopulation");
for (int i = 0; i < jsonarray.length(); i++) {
jsonobject = jsonarray.getJSONObject(i);
WorldPopulation worldpop = new WorldPopulation();
worldpop.setRank(jsonobject.optString("rank"));
worldpop.setCountry(jsonobject.optString("country"));
worldpop.setPopulation(jsonobject.optString("population"));
worldpop.setFlag(jsonobject.optString("flag"));
world.add(worldpop);
worldlist.add(jsonobject.optString("country"));
}
}catch(Exception e)
{
}
return null;
}
protected void onPostExecute(Void args) {
// Locate the spinner in activity_main.xml
Spinner mySpinner = (Spinner) findViewById(R.id.my_spinner);
// Spinner adapter
mySpinner
.setAdapter(new ArrayAdapter<String>(MainActivity.this,
android.R.layout.simple_spinner_dropdown_item,
worldlist));
// Spinner on item click listener
mySpinner
.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> arg0,
View arg1, int position, long arg3) {
// TODO Auto-generated method stub
// Locate the textviews in activity_main.xml
TextView txtrank = (TextView) findViewById(R.id.rank);
TextView txtcountry = (TextView) findViewById(R.id.country);
TextView txtpopulation = (TextView) findViewById(R.id.population);
// Set the text followed by the position
txtrank.setText("Rank : "
+ world.get(position).getRank());
txtcountry.setText("Country : "
+ world.get(position).getCountry());
txtpopulation.setText("Population : "
+ world.get(position).getPopulation());
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
}
});
}
}
}
WorldPopulation.java
WorldPopulation.java
public class WorldPopulation {
String rank,country,population,flag;
public String getRank() {
return rank;
}
public void setRank(String rank) {
this.rank = rank;
}
public String getCountry() {
return country;
}
public void setCountry(String country) {
this.country = country;
}
public String getPopulation() {
return population;
}
public void setPopulation(String population) {
this.population = population;
}
public String getFlag() {
return flag;
}
public void setFlag(String flag) {
this.flag = flag;
}
}
activity_main.cml
activity_main.cml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<Spinner
android:id="@+id/my_spinner"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/rank"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/my_spinner" />
<TextView
android:id="@+id/country"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/rank" />
<TextView
android:id="@+id/population"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/country" />
</RelativeLayout>
对齐
这篇关于填充微调使用JSON的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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