将JSONArray放入列表(Android)
我有一个项目,可以接受一个JSONObject并将其放入edittext,但我正试图找出如何更改它,以便它接受一个JSONArray并将其放入listView 这是我目前的代码:将JSONArray放入列表(Android),android,android-json,Android,Android Json,我有一个项目,可以接受一个JSONObject并将其放入edittext,但我正试图找出如何更改它,以便它接受一个JSONArray并将其放入listView 这是我目前的代码: public class Js extends Activity { private String url1 = "http://api.openweathermap.org/data/2.5/weather?q=chicago"; //private String url1 = "http://bisonsoft
public class Js extends Activity {
private String url1 = "http://api.openweathermap.org/data/2.5/weather?q=chicago";
//private String url1 = "http://bisonsoftware.us/hhs/messages.json";
private TextView temperature;//,country,temperature,humidity,pressure;
private HandleJSON obj;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_js);
//location = (EditText)findViewById(R.id.editText1);
//country = (TextView)findViewById(R.id.editText2);
temperature = (TextView)findViewById(R.id.editText3);
//humidity = (EditText)findViewById(R.id.editText4);
//pressure = (EditText)findViewById(R.id.editText5);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items
//to the action bar if it is present.
getMenuInflater().inflate(R.menu.js, menu);
return true;
}
public void open(View view){
//String url = location.getText().toString();
//String finalUrl = url1 + url;
//country.setText(url1);
obj = new HandleJSON(url1);
obj.fetchJSON();
while(obj.parsingComplete);
//country.setText(obj.getCountry());
temperature.setText(obj.getTemperature());
//humidity.setText(obj.getHumidity());
//pressure.setText(obj.getPressure());
}
}
public class HandleJSON {
//private String country = "temperature";
private String temperature = "clouds";
//private String humidity = "humidity";
//private String pressure = "pressure";
private String urlString = null;
public volatile boolean parsingComplete = true;
public HandleJSON(String url){
this.urlString = url;
}
/*public String getCountry(){
return country;
}*/
public String getTemperature(){
return temperature;
}
/*public String getHumidity(){
return humidity;
}
public String getPressure(){
return pressure;
}*/
@SuppressLint("NewApi")
public void readAndParseJSON(String in) {
try {
JSONObject reader = new JSONObject(in);
//JSONObject sys = reader.getJSONObject("main");
//country = sys.getString("temp");
JSONObject main = reader.getJSONObject("clouds");
temperature = main.getString("all");
//pressure = main.getString("pressure");
//humidity = main.getString("humidity");
parsingComplete = false;
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void fetchJSON(){
Thread thread = new Thread(new Runnable(){
@Override
public void run() {
try {
URL url = new URL(urlString);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(10000 /* milliseconds */);
conn.setConnectTimeout(15000 /* milliseconds */);
conn.setRequestMethod("GET");
conn.setDoInput(true);
// Starts the query
conn.connect();
InputStream stream = conn.getInputStream();
String data = convertStreamToString(stream);
readAndParseJSON(data);
stream.close();
} catch (Exception e) {
e.printStackTrace();
}
}
});
thread.start();
}
static String convertStreamToString(java.io.InputStream is) {
java.util.Scanner s = new java.util.Scanner(is).useDelimiter("\\A");
return s.hasNext() ? s.next() : "";
}
}
我已经尝试了一段时间,但是没有找到一个好的方法来通过解析数据的方式来实现。提前感谢您提供的任何帮助
以下是JSON:
"messages":["This is a demo message. Enjoy!","Another demonstration message stored in JSON format.","JSON stands for JavaScript Object Notation (I think)"]
你真正要问的是几个问题。你自己把它分解一下,我想你会过得轻松得多
public final class Weather {
public final String temperature;
public final String pressure;
public final String humidity;
public Weather(String temperature, String pressure, String humidity) {
this.temperature = temperature;
this.pressure = pressure;
this.humidity = humidity;
}
public static Weather valueOf(JSONObject json) throws JSONException {
String temperature = json.getString("temp");
String pressure = json.getString("pressure");
String humidity = json.getString("humidity");
}
}
为BaseAdapter
创建一个简单的子类,它接受您的Weather
并将其调整为您创建的自定义布局:
public final class WeatherAdapter extends BaseAdapter {
private final List<Weather> mWeatherList;
private final LayoutInflater mInflater;
public WeatherAdapter(Context ctx, Collection<Weather> weather) {
mInflater = LayoutInflater.from(ctx);
mWeatherList = new ArrayList<>();
mWeatherList.addAll(weather);
}
@Override public int getCount() {
// Return the size of the data set
return mWeatherList.size();
}
@Override public Weather getItem(int position) {
// Return the item in our data set at the given position
return mWeatherList.get(position);
}
@Override public long getItemId(int position) {
// Not useful in our case; just return position
return position;
}
@Override public View getView(int position, View convertView, ViewGroup parent) {
if (convertView == null) {
// There's no View to re-use, inflate a new one.
// This assumes you've created a layout "weather_list_item.xml"
// with textviews for pressure, temperature, and humidity
convertView = mInflater.inflate(R.layout.weather_list_item, parent, false);
// Cache the Views we get with findViewById() for efficiency
convertView.setTag(new WeatherViewHolder(convertView));
}
// Get the weather item for this list position
Weather weather = getItem(position);
WeatherViewHolder holder = (WeatherViewHolder) convertView.getTag();
// Assign text, icons, etc. to your layout
holder.pressure.setText(weather.pressure);
holder.temperature.setText(weather.temperature);
holder.humidity.setText(weather.humidity);
return convertView;
}
public static class WeatherViewHolder {
public final TextView pressure;
public final TextView humidity;
public final TextView temperature;
public WeatherViewHolder(View v) {
pressure = (TextView) v.findViewById(R.id.pressure);
humidity = (TextView) v.findViewById(R.id.humidity);
temperature = (TextView) v.findViewById(R.id.temperature);
}
}
}
公共最终类WeatherAdapter扩展了BaseAdapter{
私人最终名单mWeatherList;
私人最终布局平面图;
公共天气适配器(上下文ctx、集合天气){
mInflater=LayoutInflater.from(ctx);
mWeatherList=新的ArrayList();
mWeatherList.addAll(天气);
}
@重写公共int getCount(){
//返回数据集的大小
返回mWeatherList.size();
}
@覆盖公共天气getItem(内部位置){
//在给定位置返回数据集中的项
返回mWeatherList.get(位置);
}
@覆盖公共长getItemId(int位置){
//在我们的情况下没有用处;只返回位置
返回位置;
}
@覆盖公共视图getView(int位置、视图转换视图、视图组父视图){
if(convertView==null){
//没有重新使用的观点,膨胀一个新的。
//这假设您已经创建了布局“weather\u list\u item.xml”
//具有压力、温度和湿度的文本视图
convertView=mInflater.充气(R.layout.weather\u list\u项,父项,false);
//缓存使用findViewById()获得的视图以提高效率
setTag(新WeatherViewHolder(convertView));
}
//获取此列表位置的天气项目
天气=获取项目(位置);
WeatherViewHolder=(WeatherViewHolder)convertView.getTag();
//为布局指定文本、图标等
保持架压力设置文本(天气压力);
holder.temperature.setText(天气温度);
保持架.湿度.设置文本(天气.湿度);
返回视图;
}
公共静态类WeatherViewHolder{
公众舆论压力;
公共最终文本视图湿度;
公共最终文本视图温度;
公共天气视图支架(视图v){
压力=(文本视图)v.findviewbyd(R.id.pressure);
湿度=(文本视图)v.findviewbyd(R.id.湿度);
温度=(文本视图)v.findviewbyd(R.id.temperature);
}
}
}
< /代码> 首先,考虑将< <代码> JSONArray <代码>更改为<代码>字符串[]/COD>。查看以下代码块以获取示例:
String[] jsonMessages = jsonArrayToStringArray(yourJsonArray);
public String[] jsonArrayToStringArray(JSONArray arr){
List<String> list = new ArrayList<String>();
for(int i = 0; i < arr.length(); i++){
list.add(arr.getJSONObject(i).getString("name"));
}
return list.toArray(new String[list.size()]);
}
在这个ArrayAdapter
中,您使用的是预先创建的布局(这是非常基本的)。要为列表视图的每个元素创建更高级的视图,您需要制作一个自定义适配器。所以您想在列表视图中显示文本??like 1st item=这是一条演示消息。祝你愉快!。第2项=另一个以JSON格式存储的演示消息。你想要listview吗?是的,完全一样。你的问题是什么?如何解析JSON数据或如何将解析后的数据添加到列表中?你试过什么?列表在哪里?此url为“”。这只去芝加哥。正确的?如果我理解正确,您需要一个列表视图,其中每个元素都有城市名称和天气详细信息(温度、预确认、日出…)。或者你想显示一个只包含城市名称的列表,当用户点击一个城市时,一个新的活动将打开,他可以在那里看到关于该城市的所有详细信息?你想走哪条路?
ListView myListView = (ListView) findViewById(R.id.my_list_view);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, jsonMessages);
myListView.setAdapter(adapter);